Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

This paper presents a vision with practical advice and examples of how different neighbourhoods and corridors and more broadly whole cities can be adapted/future-proofed for the arrival of autonomous vehicles of various types, giving due attention to the vexed problem of how to do it to achieve sustainability (embracing social equity, respect for the opinions of various stakeholders and many other factors).

The paper is written by two very experienced and renowned emeritus professors from Australia who, as they point out in their paper, also have done extensive practical consulting work in the urban planning and transport fields in Australian cities. This combination of academic expertise and practical experience in advising various levels of government in Australia on topics related to the subject matter of the current paper, lends an authenticity and practical value to the work presented in the paper. Personally, I have used John Black’s Urban Transport Planning text from 1981 for decades in my own teaching. It is one of the clearest and most useful texts on the subject.

I thus came to review this paper with high expectations, although also with some degree of trepidation about the basic assumption of needing to get ahead of the game in preparing cities for the arrival of AVs, a technology that at present is still fraught with many problems. From a personal perspective, I can think of many more urgent issues that remain insufficiently considered and inadequately dealt with despite decades of attempts in trying to achieve greater sustainability in the urban planning and transport field. So, I was a little curious about why this particular matter of AVs seems to deserve some “urgency” in the light of the still many technological, legal, moral and other unresolved matters they present.

So, an initial problem with the paper in my view, is that it does not address at all any of these many unsolved issues with AVs. It is easy to Google this and come up with many hits both in the grey and peer-reviewed literature. Some that I found perhaps worthy of examination and maybe inclusion in the paper are:

Ethics and Information Technology (2020) 22:1–13

https://doi.org/10.1007/s10676-019-09506-1

ORIGINAL PAPER

Autonomous vehicles, trolley problems, and the law

Stephen S. Wu1

Published online: 24 December 2019

© Springer Nature B.V. 2019

https://www.futurity.org/autonomous-vehicles-av-ethics-trolley-problem-2863992-2/

There are others that discount the trolley problem per se, but focus on many other unsolved matters that surround the deployment of AVs.

BOOK

Autonomous Vehicle Ethics: The Trolley Problem and Beyond 

Get access 

Ryan Jenkins (ed.),

David Cerný (ed.),

Tomás Hríbek (ed.)

Published: 22 September 2022

https://www.brookings.edu/articles/the-folly-of-trolleys-ethical-challenges-and-autonomous-vehicles/

That said, the paper moves on with the assumption that AVs will be part of the urban system, though they give no timeframe for that. I have some scepticism here since there is a lot of hype about EVs and their market penetration and how they are going to revolutionise the sustainability of urban transport systems, if only all the petrol and diesel cars on the road could be replaced with EVs (already way too many, as the authors rightfully acknowledge, because they see AVs as a way of radically reducing urban car ownership). EVs, despite their many advantages over Otto cycle and diesel engines, in practice are highly problematic right from the beginning (e.g. sourcing the rare metals/minerals in sometimes slave-like conditions involving child labour), right through high embodied energy and cradle-to-grave resource issues. And they are not achieving anywhere near the market penetration hoped for, perhaps except in Norway and some Dutch cities such as Amsterdam. And yet, EVs are now a quite well-established and proven technology, with many competing consumer offers, whereas AVs are nowhere near this yet.

So how far ahead do we look in trying to reshape cities for new technologies before trying much harder to develop even a semblance of sustainability by reducing car ownership and use through the many current practical physical planning and urban design measures available to us, and the as yet poorly deployed economic/financial disincentives for cars like those applied in Singapore and now Shanghai, Beijing and other Chinese cities?

The failure to disincentivise cars through rational economic arguments, policies and tools is the elephant in the bedroom in transport planning, which tends to make, at least partially, a mockery of so many well-intentioned efforts to reduce car use with carrots rather than sticks. I would argue that by reducing car ownership and use through every possible available means first, would much better prepare any urban fabric for the arrival of AVs, since the need and demand for them would already have been, hopefully, decimated! I am sure both authors do not need to have these approaches spelled out.

So, to summarise so far, I would recommend that the authors add a section that tries to summarise:

(a) the current readiness of autonomous vehicles (from a variety of angles) to be deployed on roads and for this I would include buses and regular cars and (b) make a case for why it is so important to adapt cities to AVs when so many other legitimate and urgent ways of reducing car ownership and use first, are not acknowledged in the paper.

Now to the details of the paper. I shall make first some substantive conceptual comments and then some editorial comments.

Conceptual

(1)   Line 55-56. Here the different types of corridors are mentioned. Many inner-city streets in Melbourne are good examples of Type II and they have trams (see later comments about public transport). For readers, I believe it would be good to illustrate these corridor types with three photos from the Australian context to show the differences (perhaps even annotated to point out the features of importance).

(2)   Line 81: The use of the terms “transport-oriented local centres” (TOC) and “transport-oriented development” (TOD is confusing in my view. Any urban centre is transport-oriented and any urban development is transport-oriented by some description, because of, in the very least, the need to provide basic road access to every property. The proper term is Transit-Oriented Development (TOD) using the American abbreviated term for public transport. Or more latterly, the term Transit-Adjacent Development has been used where development does not quite fulfil the former. This term is an issue throughout the paper, and I am sure that the authors meant public transport-oriented development because this ties in much later in the paper where the authors emphasise public transport a little. I think it must be fixed throughout, in text and in all the diagrams.

(3)   Line 120 – the use of the term trade-offs is not applicable where sustainability is concerned. Sustainability has never been about trading-off or balancing social, economic and environmental factors off against each other. Sustainability has always been about simultaneously uplifting or improving all three factors together.

(4)   Line 211 – what did the MATSIM work in Singapore find?

(5)   Line 260 – I do not understand the sentence beginning: The rationale…

(6)   Line 297 - I feel that this is unfair wording. Pedestrians are fundamental to any urban environment and the higher their modal share the more livable generally will be the public realm. I think it is not right to cast the presence of pedestrians as a problem for a movement corridor. I do not think the authors meant it this way, or at least I hope they did not, but the wording is open to misinterpretation.

(7)   Line 314 - the risk of pedestrians to the safe functioning of AVs seems around the wrong way and suggests that AVs are the main thing to be considered. Cities are meant to be for people. Again, I cannot imagine the authors meant for this interpretation, but it is poorly worded and could be construed in this way.

(8)   Figure 2 – It says parking restrictions affect business. Which way? Do they really negatively impact business? If the corridor is kept on the movement economy through foot, bike and public transport, then businesses do fine or even better than if they are car dependent, if the livability and attractiveness of the street is improved by parking limitations (which normally it should be). Business definitely perceives parking restrictions as a threat but if projects are well done, often pedestrianisation or traffic calming projects result in businesses asking that the restrictions be extended to them because those inside the project very often do much better.

(9)   Lines 353-356 - Again, there seems to be a perhaps unintended bias here towards the rights of AVs in the way the argument is cast. If AVs are to play a part in cities, then they need to be good enough to recognise people and be able to minimise problems, especially sudden and unexpected problems, not the other way around. As Lewis Mumford once said in the 1960s "Does the city exist for people or for cars?”

(10)                       Line 453 TOD and TOC…this is definitely meant to be Transit-Oriented since these acronyms are always translated as such.

(11)                       Table 1 – Strangely, this table has no mention at all of public transport, walking or cycling.

(12)                       Table 2 – under Safety – I think again this wording is ill-considered, perhaps again not intentionally by the authors. But let’s be clear here. Pedestrians have been the basis of cities for 10,000 years or so. The car as a mass consumption item and urban transformative technology, only began less than 100 years ago, so personally I find it a little absurd to suggest that humans have to be reprogrammed to allow AVs to operate. The AVs have to be advanced enough and “programmed” correctly before introducing them. Do humans have to be reprogrammed to stop using their mobile phones in an unsafe way? Maybe there is a bit of basic safety education required here, but if cities were truly designed around the needs of pedestrians the risk of errant mobile phone behaviour would be very much reduced. And maybe if cities were more interesting and inviting to pedestrians, everybody would not be walking around with their faces in their phones, which I could well-imagine might at least be a future partial cause of AV/pedestrian conflict!

(13)                       Line 497 – the sentence starting here makes an unsupported claim about the economics being able to work.

(14)                       Lines 499-500 – Good, BUT but the way the paper is written this is not made clear enough because of the focus on AVs (mainly private or shared or AV taxis, I am not really sure so far).

(15)                       Line 500 – mentions autonomous metro. First of all, does it have to be autonomous? Isn’t a regular subway/metro with a driver also good enough for a great public transport service in a hub? And why is it only autonomous buses? What about trackless tram potential?

(16)                       Figure 6 – In the diagram the only visible public transport is a local bus – what about streets like in Melbourne that function well with trams and/or the authors could consider showing a rail station too to coincide with the preceding text.

(17)                       Line 513 – The data seem to imply that 70% of people use cars, all single occupancy…is that right? Seems to me that this is not a step towards sustainability.

(18)                       Figure 7 – In part 2 and 3 of this figure where would the essential strong transit orientation happen? Where would the metro station be or a light rail line?

(19)                       Lines 533-541 - I think there is a need to try to generalise here and not to assume Australia. Some of the text seems to relate to Australian projects but in a paper of this nature the context is missing and therefore the authors I think inadvertently write as though there is a well-informed Australian readership.

(20)                        Line 557 - Does this mean a metro as in train, because the text so far has been somewhat ambiguous as to where, how and what type of public transport fits into mobility hubs? Buses are the most obvious so far, the way it is written.

(21)                       Line 573 – Isn’t the aim to increase accessibility not mobility per se? Since the advent of the car we have been replacing easy accessibility to, for example, a corner shop (300 to 400 metre walk that a child could do) with a 3 to 5 km drive in a car to a suburban shopping centre (mobility).

(22)                       Line 593 - The more you do this, the less need there is for private transport per se, apart from bikes, e-bikes and feral transport.

(23)                       Line 597 - How do you coordinate this over a multitude of LGAs in any city?

(24)                       Lines 599-601 Does not this assume a high level of competence and knowledge which may not be present in every case?

(25)                       Line 606 - Low density is a loaded term which means different things in different places around the world. Low density in Australian cities is about 4 persons per ha up to say 20 per ha. Densities in Mumbai, which are around 300 per ha or more, for example, would be considered low if they were 40 to 50 per ha. On the contrary most Australian cities would consider the latter densities quite aspirational! This is where the paper falls into assumptions about the nature of the readership and I think needs to be clarified.

(26)                                       Line 612 - I think this is irrelevant to have a 1976 population for a paper 50 years later! I can see how it relates to the Figure which contains the area, but has it changed (population?), what does it look like now? Maybe an aerial photo?

(27)                                       Line 622 - 50-60 km/h is not a low-speed environment universally or even especially low speed anywhere...In Europe most residential streets are 30 km/h, with Verkerhsberuhigung areas at 10 km/h, so again I think that the paper must be careful not to appear normative when it is only referring to Australia.

(28)                       Lines 624-626 What? This is being done already, even when there are no AVs to speak of?? Really? Can this be clarified?

(29)                       Line 636 - What are we talking about here? Is this a theoretical place or a real place? The seeming jump from a real example to possibly a speculative one is confusing and needs clarification.

(30)                       Line 637 - What kind of public transport services?...again it appears to be solely bus-based. Even Canberra has light rail today.

(31)                       Lines 638-639 - There are today possibilities for autonomous rail rapid transit on street such as trackless trams. I think it is wrong to be always assuming buses as the basis of public transport. At least the writing appears to suggest this. If I am being unfair here, then please improve the writing.

(32)                       Figure 9 - I am intrigued to hear from the authors what they would consider to be acceptable or aspirational modal splits % for walk, bike (including e-bike or lightly motorised modes) plus, public transport (maybe split between bus and rail modes) and finally motorised private transport including all AV trips. I think this is critical otherwise it could look like they are redesigning cities for a preponderance of cars (see previous comment), just that they are AV and maybe not all privately owned.

(33)                       Lines 648-649 - This wording is insensitive in my view. Pedestrians are not the cause of problems, they are the solution. Vehicles are the problem, autonomous or not. So, while the paper pays some ambiguous priority to pedestrians and their needs, some of the wording betrays a seeming bias towards "car mobility", which I think is inappropriate in a Sustainability journal regardless of whether AVs reach any level of penetration in urban systems within say the next 10 years, or not. Certainly, electric car penetration rates have been lacklustre in most countries despite all the "silver bullet" hype about electro-mobility. If the authors are not guilty of this bias towards private motorised mobility, then it is up to them to strengthen what on many occasions is a sloppily written piece of work with a preponderance of errors that simply should not be there if they took serious care with this paper.

(34)                       Line 649 – Again, the wording here is strange. In the previous sentence pedestrians are the major CAUSE of problems and now there is concern about the risks that AVs present TO pedestrians. The AVs DO present a risk to pedestrians not the other way around. Jane Jacobs would turn over in her grave at the suggestion that somehow cities must adapt to AVs when AVs are the interlopers, as was the car in the first instance, when it destroyed so many traditional urban fabrics. And it was our collective acquiescence to the car's demands that is the major source of many urban problems today. Pedestrian and cycle traffic is a solution, as is public transport, especially rail, and cities should be being optimised for them not for AVs. I am hoping that this is what the authors intended, but the paper is I think quite schizophrenic/ambiguous, which in turn I think suggests a somewhat ad hoc and inadequate process in putting it together.

(35)                       Figure 10 – “pedestrians in a different world”… what does this mean? Also Figure 10 is shown as Figure 6 in the diagram. Again, sloppy proof-reading.

(36)                        Lines 663-664 – Here, there is the same assumption that this paper is all about Australia. While it has been developed in an Australian context, many readers would not know much about Queensland or Tasmania, so I think it is better to try to generalise this a bit better. The way it is written now appears to have dropped material in from Australian reports without due consideration to how it works in a paper of wider import in an international journal.

(37)                       Lines 667-668 - The priority here seems to slip through again that this is all about improving things for cars. Granted, it is preceded by warm and fuzzy talk about making things clearer and nicer for pedestrians, but then it flips to accommodating faster AVs. Why? What is the real, core aim here? What is the overall vision? It seems to me that in the end the paper is more about autonomous mobility than it is about genuine positive change in cities, prioritising other desperate needs for saner, more equitable, and sustainable urban fabrics which tries in every way possible to minimise cars and car speeds per se, not to try to make things better for AVs. If this is not the intention of the authors to be cast in this light, then there needs to be a thoroughgoing look at the whole paper and how it hangs together as a coherent argument.

(38)                       Line 669 - And what is the other photo? Why explain just the top photo?

(39)                       Figure 11 - The bottom photo is distorted...compressed vertically if you look at the man in the photo.

(40)                       Line 717 - I did not at all get that all the AVs in the preceding text are taxis!! If this is a summary, then it needs to be made much clearer that the "vision" in the paper is not of private AVs or even shared AVs, but it is now just autonomous taxis!!

(41)                       Line 718 - I did not get any strong sense that somehow this whole effort is all about shifting demand to public transport!! For me as a summary, it does not gel at all well with what I have read so far.

(42)                       Line 720 – this is the first time that the term basement rail systems is mentioned and none of the diagrams feature it.

(43)                       Figure 12 - Do you really trust air taxis when 1000s are killed on the roads even after the car has been around for 125 years or so. I think technologically the authors are getting a bit ahead of themselves.

(44)                       Figure 12 again: How can this vision be about increasing demand for public transport when in Figure 12 there is one reference to public transport in the whole thing (full autonomous metro)...no buses, no light rail. It seems to be all about shifting to AVs. The paper for me is schizophrenic and does not have any clear, consistent theme that links through the whole writing process, especially not about sustainability. It has all the hallmarks of a patched together job from the authors' previous reports without any dedicated effort to smooth it all together into a coherent piece that is truly about improving urban sustainability.

(45)                       Line 728 - what is being referred to here?...AV taxis, AV shared cars, personal AV cars, AV buses, fully autonomous metro, autonomous on-street light rail e.g. trackless trams. All the way through the paper, there is a lot of confusion about what the authors are really talking about.

(46)                       Line 736 - The main change has been how such areas have been impacted by cars in the first instance. Is it not a much better idea to devote thought and effort to how to fix the problems imposed by cars per se, rather than jumping on a band wagon about how we can plan to again adapt urban fabrics for the next wave of electric, autonomous vehicles which, anyway, are so far still a bit in the same realm as Elon Musk's hyperloop dream.

(47)                       Lines 746-758 - Where in this text is there anything about increasing the demand for public transport?

(48)                       Line 763 - I do not think this has been achieved...perhaps Australia, New Zealand, the USA and Canada, but there is a lot more world out there with dramatically different cities to these car-centric places.

(49)                       Lines 763-765 – This sentence I find staggering. I do not think traditional cities with narrow streets deserve or require this kind of vandalism.

(50)                       Lines 777-780: This is written as though it means something to the non-Australian reader or even the non-informed Australian reader. The problem seems to be that these pieces of text may have been taken out of context of another document or other consulting work that the authors have informed readers of in general terms in the paper and then have pasted into this paper as though they fitted without the needed context.

(51)                       Line 784 - Nice idea but how much private mobility (presumably the authors here mean private mobility in autonomous cars of some description) compared to walking, cycling and public transport? What is the authors’ vision of some idealised modal split? Is it 20% private transport (AVs etc), 25% walking, 25% cycling and 30% public transport? What are we talking about here to be clear how all the ideas about reshaping urban systems for AVs plays out in practice? Without this more solid vision, based on some data, the importance of which is emphasised in other parts by the authors, they risk leaving this AV transformation of neighbourhoods and cities up in the air and open to all manner of interpretation. This might range from a continuation of excessive car dependence, as in evidence in the USA and Australia in particular, or some more radical reshaping of cities with higher densities and mixed land uses (which the authors seem to favour and which leads to very much reduced modal split to private transport). This ultimately determines the paper's worthiness to be badged up with Sustainability credentials.

(52)                       Line 785 – I think this discussion should appear logically from what precedes it. For this reader, nowhere did I get this kind of strong message about public transport. AND this statement is ambiguous because there are many forms of public transport, buses, LRT, metro, suburban rail, regional rail, ferries...what kind of public transport is being emphasised here and how does it relate to AVs.

(53)                       Lines 786-787 - This is confusing since a little way back the authors were talking about fully autonomous taxi services, now they are talking of AVs provided presumably as shared mobility services. Which will it be, Both perhaps? This all needs to be sorted out in the paper.

(54)                       Lines 789-790 - I really don't get this. Is this going too far?

(55)                       Lines 790-793 - For me this goes too far off song in relation to the rest of the paper. For this to be relevant I feel that somewhere in the paper these kinds of rather futuristic ideas would need to have at least been brought up.

(56)                       Line 795 - A bit presumptuous that all would be on board this thought. I think the most that can be said is ”one possible future for cities.”

(57)                       Line 815-816 – Like what?

(58)                       Lines 821-822 - This is a good point but for me in the main body of the paper it was not apparent, especially the rail aspect. There needs to be a much clearer enunciation throughout of how central public transport is to their aims and importantly what TYPE of public transport and where. All the obvious on-street public transport in the paper is buses which overlooks a quiet LRT revolution, including in Adelaide, Sydney, Canberra and at least the Gold Coast area of "Brisbane"...and of course around the world as well. The paper only mentions metro (as in rail) twice in 34 pages!! Maybe trams are avoided since they may pose another level of complexity on the smooth operation of AVs?

(59)                       Line 824 – reducing private vehicle usage - Great but to what extent...any vision of that? How does it gel with 700 AVs per 1000 early in the paper.

(60)                       Last section - As it is customary not to introduce new ideas and references in what is strictly a conclusion to a piece of work, I would suggest that this last paragraph be sub-headed as Suggestions for further research.

Editorial

This paper is very badly proofread which really surprises me given the calibre of the authors. At times I felt like I was reading a poorly presented thesis.

Line 81: provide not providing.

Line 112 that that.

Lines 185 and 186 – Toyota not Toyoto and is not ais.

Lines 220/221 – detailed not detail and described not desibed.

Line 244 – too not to

Line 320 – in any transition, not the.

Line 365 – accidents and Precincts are joined.

Line 366 – providing not proving

Line 377 – are not is

Table 1 – local place not plac (top left hand)

Table 1 – What they can achieve…”the disabled” has long been relegated to the dustbin of offensive caricatures. I believe the current term is “differently-abled” and not even “people with disabilities”.

Line 488 – the “sentence” starting Line 488 is not a sentence.

Line 493 – surrounded not surrounding.

Figure 6 caption – precinct, not precincts.

Line 512 – turn out I think must have a hyphen or maybe it is one word these days.

Line 543 – We believe, not we belief.

Line 552 – remove space between could and become.

Line 566 – remove space between appropriate and clothing.

Line 583 – vehicles not vehicle.

Lines 615-617 – not a sentence!

Line 623 – do not does

Line 635 – Two cases of This illustration.

Line 648 – Type II corridors not Type corridors

Line 694-710 – This whole block of text repeats from previously and is astoundingly bad proofreading!

Line 717 – serviced not servived

Line 812 and 813 – be not abe and accommodated not commodated.

Line 837 – provide, not provides

Summary

In summary, I could not recommend publication of this paper in its present form. I think it essentially needs to be re-written to make it clearer where the authors stand in their vision of AVs in the city and the roles of public transport, walking and cycling. I have tried to give as detailed guidance as possible on this.

In terms of the written quality, there are far too many errors which indicate possibly a cobbled together piece of work without any effort at genuine proofreading. The use of material from Australian consulting projects appears to have been dropped in without any serious effort to smooth all this out in how it appears to readers. There are too many assumptions about knowledge of Australian cities. If it remains focussed on Australian cities, then readers need to be given better background and guidance in understanding it. Or they generalise it better just using Australian examples.

Finally, I feel that the paper would benefit from photographs to better illustrate many of the concepts in the paper about mobility hubs and corridor types etc.

The authors state that many people commented/read this paper. Based on my reading of it, they seem to have let the authors down.

 

Comments on the Quality of English Language

There are a very surprisingly large number of errors indicating poor proofreading and one big block of text repeats (see detailed comments)

Author Response

please see the attachment

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

This study presents a comprehensive perspective necessary for urban built form in anticipation of the advent of an automated society, and has useful information for the future development of research in this field. While many references are cited to develop the argument, there are also discussions based on the authors' findings. However, as there are few similar studies, it is highly worth publishing.

The following is a list of references and parts of the text that need to be corrected.

1) Line 185: The correct word is "Toyota", not "Toyoto".

2) Line 191: As a Japanese case study, the Tokyo Metropolitan Government has published "How to Create a City for an Automated Driving Society" (in Japanese), which may be a good reference. However, since it is in Japanese, whether or not to cite it is left up to the authors.

https://www.toshiseibi.metro.tokyo.lg.jp/bunyabetsu/kotsu_butsuryu/jido_unten.html

3) Line 193: There is no citation in this sentence, so it is desirable to add one. Since the documents and meeting minutes of this review meeting are available on the following web site, it is desirable to indicate the URL as a reference.

https://www.mlit.go.jp/toshi/toshi_gairo_tk_000079.html

4) Line 500: As a transportation plan, the description regarding the relationship with other transportation modes is insufficient. How about adding the necessity of AV and its role from an urban planning perspective?

5) Line 549: It seems necessary to optimize the transportation network including AV and public transportation. How about describing it more carefully?

6) Lines 692-710: This sentence is exactly the same as lines 549-567. It needs to be reconsidered.

 

Author Response

Response to Reviewer 2

Reviewer 2

Dear Authors,

Thank you for your response which, in the main, was adequate. I write to you with a single issue that remains unresolved and speaks to your own reputations and that of the esteemed journal. The second sentence of the abstract remains problematic. I urge the authors to write in terms of probabilities or likelihoods. >>>>This correction in the Abstract has been made

A literature review found no evidence that there is any understanding of what it takes to plan land uses for the transition to fully autonomous vehicles at the precinct level, nor any conceptual agreement on the nature of the transformation of roads and their frontages. The methodology is based on the authors’ previous research and development into road friction and impact that led to the production of Australian government guidelines as summarised in Section 2. A case study of the City of Unley, South Australia, demonstrates the principles of risk analysis and risk management. Examples are then given on how to modify road movement corridors and adjacent land-use precincts in low-density, car-dependent environments, in high density mixed land-use areas, in consolidating residential lots along movement corridors, and in areas with mobility hubs, all illustrated using conceptual sketches and plans. The conclusion suggests directions for further research of which collaborative workshops are needed involving different disciplinary perspectives to the land-use planning approach advocated in this paper.

 

Equally, I suggest the authors apply qualifications to their arguments. For example, do the authors have unfettered access to all of the research undertaken by Google and Tesla, much of which could be protected by non-disclosure agreements. >>>>>No we have not accessed any information from research undertaken by Tesla or Google (the first author owns and drives a Tesla)

Did the authors search the journals written in Chinese? >>>> We do not read Chinese and have not attempted to use Google Translator on AV papers in Chinese. However, our topic is about land-use planning for AVs and if the reviewer can point us to a paper in Chinese on this very specialised topic then we will consider its context.

I respectfully request the authors to modify the language accordingly.

Preparing for Fully Autonomous Vehicles in Australian Cities: Land-Use Planning - Adapting, Transforming, and Innovating

 

Hans Westerman ¹ and John Black ^2,*

Citation: To be added by editorial staff during production. Academic Editor: Firstname Lastname Received: date Revised: date                                     Accepted: date Published: date Copyright: © 2024 by the authors. Submitted for possible open access publication under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/).

¹    University of New South Wales, Sydney; [email protected]

²    University of New South Wales, Sydney; [email protected]

*   Correspondence: [email protected]: Tel.: 61 418203905

Abstract:
Abstract:
A literature review found no evidence that there is any understanding of what it takes to plan land uses for the transition to fully autonomous vehicles at the precinct level, nor any conceptual agreement on the nature of the transformation of roads and their frontages. The methodology is based on the authors’ previous research into road friction and impact that led to the production of Australian government guidelines as summarised in Section 2. A case study of the City of Unley, South Australia, demonstrates the principles of risk analysis and risk management. Examples are then given on how to modify road movement corridors and adjacent land-use precincts in low-density, car-dependent environments, in high density mixed land-use areas, in consolidating residential lots along movement corridors, and in areas with mobility hubs, all illustrated using conceptual sketches and plans. The conclusion suggests directions for further research of which collaborative workshops are needed involving different disciplinary perspectives to the land-use planning approach advocated in this paper.

 

Keywords: Autonomous vehicles; land-use planning; road friction and impact risk assessment; mobility hubs with autonomous vehicles

 

1. Introduction

According to Duarte and Ratti [1], autonomous vehicles “offer the first opportunity to rethink urban life and city design since cars replaced horse-powered traffic and changed the design of cities for a hundred years”.

Self-driving cars (AVs) are already being trialled in the field,autonomous vehicles are offering taxi services in San Francisco and Los Angeles, California, and Toyota’s Woven City near Shizuoka, Japan, will have people and fully autonomous vehicles mixing on surface roads.We suggestthat as this vehicle technology matures there are opportunites for a new level of integrated land-use and transport management with the modification of road frontages, the introduction of multi-modal mobility hubs, and advances in AI and communication technology.The importance of land-use planning to complement a transition to autonomous vehicles is demonstrated in this paper.

 

Currently, no evidence can be found that there is any understanding of what it takes to plan land uses for thetransition of fully autonomous AVs into the urban fabric nor any conceptual agreement on the nature of the transformation of roads and their frontages, precincts and mobility hubs, and the options as to how to safely introduce AVs to avoid risks to people. This paper introduces how such modifications to urban spaces can be achieved with an emphasis on personal fully autonomous vehicles, community-owned AVs , public transport services and AV taxi services. Road frontages and abutting land-use activities represent a microcosm of the myriad of issues facing socio-technical systems interacting throughout the city [2]. This specific microcosm contains unwanted vehicular impacts such as the intrusion of road traffic noise and harmful vehicle emissions; accidents involving pedestrians, cyclists, and vehicles in the road space; and the unnecessary “friction of land-use activities” imposed on the free-flow of vehicles through driveway, parking and un-parking manoeuvres, and pedestrians crossing the road at undesignated places [3,4, 5, 6].

 

The analysis of “friction and impact” is based on our previous research into Australian cities and suburbswhere driving is on the left-hand side of a road, and this provides

a

 

a starting point for a risk-based approach to land-use planning for future cities with AVs. Whilst fieldwork with video cameras recording all personal and vehicle interactions in the defined roadspace was deployed to establish friction and impact, advances in data collection and systems models would be now a more appropriate methodology.  When road corridors are classified by function it is clear there are three types: Type I, where vehicular movement corridors are paramount; Type II where both movement and property access are important in the corridor, such as commercial strings along sub-arterial roads; and Type III, where access to properties dominate, such as streets in residential suburbs, or in industrial estates. Precincts are more complex in scale and land-use function but can be classified into precincts with low-residential density, medium-residential density, high-residential density, industrial precincts, and multi-activity precincts with residential, commercial, retail and entertainment land uses where people and vehicles mix in confined spaces. Corridors and precincts produce a matrix into which different physical solutions need to be found for the safe adaptation of new transport technologies, and what to do about modifying buildings and site access, offering mobility for the elderly [7],other sections of the community and not compromising current urban transport and urban planning objectives [8].

 

The methodology involves a search of literature on autonomous vehicles and the urban built form, and a review of how autonomous vehicles have been deployed, and are planned to be, deployed in cities. In applying the systems engineering approach to risk we draw on our extensive professional and academic experience in researching and writing guidelines for Australian government agencies, such as local area traffic management [9], sharing the main street and the environmental adaptation of roads and their frontages [10], and for body corporates - Guide to Future-ready Apartments [11]. The first author was Chief Planner and Associate commissioner with the then National Capital Development Commission, Canberra, and both authors have acted as independent consultants to national, state, and local governments and community organisations on various strategic and action planning studies. We have been involved in planning and building new towns and working with communities, so we understand the complexities in managing change and the system approach [12, 13. 14].

 

Based on the literature review, we have found no evidence so far that anyone is approaching the introduction of AVs into the urban built form from the following six perspectives: a risk management framework; a fundamental understanding of the existing urban structure and the road environment (studies of retrofitting would be the nearest, but without insight into barriers to overcome in an economic, property, governance, infrastructure and financial context); insight into the management of existing mixed-use road corridors (especially Type II); creating mobility hubs as the new autonomous multi-modal, transit-oriented local centres providing: autonomous connectivity, equitable access for anyone, at anytime, anywhere, with local business services and community facilities above the ground floor transport hub;  managing precinct AV (including waste disposal) operations below, above and at ground; and changing the need for private car ownership through public perception and practice by creating a financially attractive, functionally efficient and superior alternative to current mode choices.

 

The significance of finding successful pathways to accommodate autonomous vehicles in the city, such as the approach suggested in this paper, is obvious in terms of sustainability objectives. At its most basic level, it is the role of governments to efficiently and safely allocate (road) space to different users. This takes the form today of road hierarchy policies with residential areas being protected by engineering design devices from the intrusion of fast-moving vehicles, the designation of lanes for high-occupancy vehicle or buses, reducing space for motor vehicles to insert tram tracks or cycle paths, or excluding vehicles entirely from certain streets. The land-use planning processes described in this paper are aimed to be an aid to policy makers in their deliberations with stakeholders and the wider community about the future of AVs in the city.

 

The structure of the paper is as follows. The methodology of the literature review and the perspective on urban planning, including the role of precincts and corridors, together with the essential element of stakeholder and community consultation is presented in Section 2 – Materials and Methods. This section clarifies risk associated with friction and impacts in precincts and corridors illustrated with a case study of Unley City in South Australia. This methodology has been updated by the authors to include fully autonomous vehicles. The results section (3) illustrates the adaptation of a land-use strategy into a risk management strategy and explains the risk management of AVs in precincts and corridors along with examples drawn from different types and precincts and corridors – low density suburbs, . This is followed by a discission (Section 4) and a conclusion (section 5) that summarises the paper and identifies areas of further research.

2. Materials and Methods

2.1. Literature Review

 

The methodology used in the construction of this paper involves a search of related literature on autonomous vehicles and the urban built form. An enormous volume of literature has been published on autonomous vehicles, and a Google Scholar® search using key words “autonomous driving vehicles” retrieved 1.32 million items. By adding additional qualifiers with the key words “autonomous driving vehicles, integration into cities, and built form” the search yielded 102,000 results. Working through the abstracts from the most recent articles listed, and culling by title, we continued until we believed that all of the themes had been exhausted (Section 3). Whilst we cannot be certain that that outside of Australia some researchers may have already published future proof guidelines on planning AVs in urban areas, the peer review process should identify such literature. As our ideas became more solidified it was necessary to include “mobility hubs” into the literature search.

 

To achieve the millennium sustainable development goals, an important theme in the academic literature on urban planning, is the focus on policy options to achieve more sustainable cities in terms of economic efficiency, environmental performance, and social justice. This follows closely the ground-breaking report by the Brundtland Commission [15]. Policy evaluation entails trade-offs amongst competing objectives where one of the goals of urban planning is the formulation of regulations (and codes of practice) that minimise the externalities of government and private development. Whilst urban land-use and transport planning is a mature field of practice, understanding the broader impacts of autonomous vehicles on the city is an emerging area of research with the purpose of this literature review being to identify broad themes currently being investigated.

 

The advantages of AVs in the city are explored by Olayode [16]. One prediction is that only 6 per cent of personal vehicles sold in the world by 2035 will possess even a limited version of autonomous vehicle (AV) technology described as "Level 4" under the SAE J3016 [17]. However, it is now opportune to think seriously and systematically on details about fully AVs in the future city. There are visionary architects who illustrate ideas of the future, and this brings to the fore building design and building management systems as well as the role of body corporates (strata managers), in the future proofing of residential and commercial precincts.

 

There are no shortages of essays by architects on the design of future cities [18] and there are also a few books on this topic [19, 20]. At the scale of a free-standing house the Renault car company commissioned an architectural firm that integrates an AV into the built fabric [21]. Whilst it is probable that some architectural firms are considering how to integrate AVs into buildings at the precinct level, search of research data bases does not retrieve any publications. It is most likely that urban governments have prepared precinct master plans that include future transport technologies. For example, in Sydney, the New South Government, Landcom [22] has published a report based on a literature review, of the factors to consider when planning future precincts that have AVs in operation, but neither the New South Wales Infrastructure Plan [23], nor the Roads Future 2056 document [24] add anything of substance as to how AVs might function in the city.

 

One obvious research theme is the questioning by urban planners of how to manage the “disruptive” technology of fully autonomous driving vehicles [25]. There is a critical role of urban planning, regulations, and policy making for mitigating any disruptive impacts of autonomous driving technology. “Ultimately, the future role of AVs in influencing urban form and structure is not so much dependent on the technology and level of automation of vehicles but rather on the regulation of this technology and the governance of cities and regions” [26, p 132). Similarly, Legacy and others [27] reviewed an extensive literature base, and conducted interviews with public-sector planners to determine the conceptual gaps in the framing of AV technology and the city. The authors raise questions about the role that urban planning can play in the rollout of AVs in anticipation, and in the mediation, of unwanted built environment and socio-spatial impacts. Focus groups conducted in Manchester (England) and Melbourne (Australia) confirm that a significant role of urban governance is to mediate the politics and resolve contestations in critical areas: data management and privacy; cybersecurity; viable business models; and ownership arrangements [28]. In a case study of a desired vision for Turin, Italy, Brovarone and others [29] formulated a package of measures allocated over a 30-year time horizon to govern the transition to autonomous driving towards urban liveability and sustainability.

 

All policies and projects require detailed evaluation against general goals and more specific objectives and recommendations made to decision makers in the summary form of a business case. Currently, the main area of research is the costs and benefits associated with the modification of existing infrastructure [30]. A study by Maheshwari and Axhausen [31] investigated how the technological shift in transport towards AVs might impact on the sustainability of cities or otherwise based on a review of the literature. There are potential cost savings by narrowing vehicle lanes on roads and in parking lots. As the needs for safe and efficient operation of AVs and connected AVs may differ in at least some aspects from the needs of human road users, Austroads [32] identified several potential physical infrastructure improvements that appear valuable for supporting AV uptake, but which have more challenging economic investment cases. The report concluded only traffic signals, signage, and line markings had strong B/C ratios of greater than 3.4, whereas the implementation of remote AV parking facilities and mobility hubs had a marginal B/C ratio of 1.2. Further research is in progress, but we have not been able to find data on the economic costs and benefits of any entire precinct transformation.

 

A dominant theme in the literature is speculation about the impacts of fully autonomous vehicles (and traditional vehicles) at the metropolitan scale [33]. A major contribution was made by Yigitcanlar and others [26] who summarised diverse views on the likely impacts of AVs based on optimistic and pessimistic perspectives. Topics covered: the built environment and land use; environmental sustainability; intermodal traffic regulations; transport network design; network information systems; sensitive data management; public transport; parking; and automated cooperation. AVs offer the potential to reduce the urban space requirements for roads and parking, to create more space for high-quality, liveable areas, but AVs might also lead to greater motorisation and the availability to perform leisure or work activities while travelling in AVs that could increase the number of trips and travel distances, encouraging urban traffic congestion and sprawl. According to González-González and others [34], these findings point to the need for a mixed land-use policy, the clustering of urban facilities and services, the restriction of motorised access in cities and the adoption of shared high-quality multi-model transport. A matrix of new transport technologies arranged by their suitability and efficiency to perform various origin-destination tasks in the city has led to a schematic layout of a future city with autonomous vehicles [35].

 

There is a long history of visionary statements on planned cities of the future. For example, Le Corbusier designated 7 types of roadways (plus a cycleway) for different precincts in his plan of a new Indian city in Chandigarh [36]. A contemporary example of a city under development that fully integrates AVs into the built form of cities is the Toyoto Motor Company and Woven Planet Holdings, Inc. (Woven Planet) “Woven City.”. It ais located on a 71-hectare disused site adjacent to the former Higashi-Fuji Plant site of Toyota Motor East Japan, Inc in Susono City, Shizuoka Prefecture, Japan. Only fully autonomous, zero-emission vehicles will be allowed to travel on the main streets. Woven City will have three types of streets interwoven with each other on the ground level: one dedicated to automated vehicle driving; one to pedestrians; and one to pedestrians using personal mobility vehicles. Underground there will be roads used to transport goods and waste [37]. The Japanese Ministry of Land, Infrastructure, Transport and Tourism has, since 2017, a working group studying cities that are compatible with automated driving, and a report in Englih is expected later in 2024 (Professor Morimoto, pers. com.)

 

Publications on the impact of AVs at the sub-metropolitan scale are less common, but parking is one of themes that has been given attention. If we assume that private car ownership declines in the future, and is replaced by on-demand, autonomous vehicle taxi services, then parking in front of houses and apartments can be transformed into pedestrian spaces or bicycle lanes. In residential areas with more dense buildings there will be no need for parking, and, in busy commercial centres, the need for parking stations can be eliminated. Parking will exist as charging stations on the periphery of the city [38]. One of the most comprehensive frameworks to study the future of the motor car, with its planning principles, regulatory mechanisms, and policy instruments, has been devised by the MIT Urban Mobility Lab (https://mobility.mit.edu). For example, one important topic is the future of parking, addressed through regulatory powers of land-use zoning and policy instruments, such as reducing the provision for parking spaces, and examining alternative uses of that land.

 

One of the few publications on autonomous vehicles and precincts is by a site engineering and design company, Utilities One, who set out key elements of precinct green design. However, the section devoted to designing for AV integration is limited to efficient site planning, including designing roads that optimise traffic flows and minimise congestion [39]. The most comprehensive examination of aspects of urban planning and design for precincts is by Maheshwari [40] who constructed scenarios around autonomous vehicles and all modes of transport for a precinct in Singapore using the MATSim mathematical model [41]. This research opens the door for further studies of AVs in precincts based on other types of performance criteria including risk to road users and pedestrians..

 

An emerging theme in the literature on smart cities is the concept of a “mobility hub”. A “mobility hub” is a recent term replacing a “multimodal interchange” and is widely seen as a physical place where different transport modes interconnect in a seamless way for the traveller. The numerous definitions of mobility hubs are given in {42, 43}. Arup/RISE [44, p.10)) point out “the mobility hub framework and its programming are based on the idea of mobility and service elements” such as coffee shops, small-scale retailing and personal services complementing each other. Illustrations of mobility hubs are provided for several cities of the world. Based on an analysis of 20 mobility hub networks across the world, Arnold and others [45] highlight the diversity of their objectives, design, and features. Detail examples of mobility hubs in the Netherlands are desibed in [46]. These studies focus on current operations and do not consider how mobility hubs can transition into a future with autonomous vehicles.

 

Whilst we have not attempted to find out if there are any relevant overseas urban design guidelines that include AVs, we have carefully examined Australian Government documents without discovering anything novel. Current State Government urban design guidelines are devoid of issues relating to the impact of new transport technologies, such as AVs, on urban form and function. The most progressive guideline is The ACT Urban Design Guide that acknowledges the need to provide charging infrastructure for electric vehicles, including in apartment buildings for residents and visitors in anticipation of the future electrification of the vehicle fleet [47]. The New South Wales equivalent guide places emphasis on walking, cycling and public transport in precincts [48], but makes no mention of transitions to new transport technology, which is surprising given its recent publication date. Similarly, Section 2 of the Victorian Urban Design Guidelines - Movement Network – places emphasis on the movement of pedestrians and cyclists and how they interact with motorists, including safety in car parks [49]. However, there is no mention of how to design for future transport technologies. Schedule 1 – Design Principles of the Western Australia Government guidelines mentions pedestrian movement as a priority over vehicles and the design of vehicular transport routes should “integrate safety requirements in a manner that mitigates negative impacts on pedestrian amenity” [50, p. 11], in Brisbane, Queensland, Northshore Hamilton is a priority development area, yet the documentation for developments remains silent about AVs [51].

 

In multi-occupancy buildings, strata title to individual premises is a common legal arrangement. These buildings are managed by a body corporate comprising representatives of property owners with an elected chairperson, or with a professional building manager [52]. Legislation makes it clear of the duties and function of a body corporate (for example, in Queensland, Australia, the Body Corporate and Community Management Act 1997). Westerman [11] argues that the functions of current body corporate committees are too narrow and should take a more strategic planning view of how to respond appropriately to future challenges such as climate change or the introduction of autonomous vehicles.

 

The research gaps that we have identified from the search of the literature is that there are no urban planning design guidelines, nor urban land-use and transport planning processes that focus on the integration of autonomous vehicles at the precinct scale and corridors of Type II level. There appear to be no urban design guidelines on how to accommodate AVs into the urban fabric, nor any case studies that evaluate the costs and benefits of AVs. At this level, and assuming high-density developments, the individual building becomes of interest with facility managers increasingly turning to AI to optimise green building performance. Building managers and body corporates must be pro-active and anticipate the integration of AVs and mobility as a service (MaaS) into their strategic planning. There are no policies and examples of risk management at the Type II corridor level, aimed at reducing the impact of unpredictable human behaviour on AVs.

2.2. Urban Planning Perspective

 

The methodology is from an urban planning perspective informed by our collective experience in researching and writing guidelines for Australian government agencies, such as local area traffic management The rationale for these works is on systems engineering flow diagrams. We have also given extensive professional consulting advice to all levels of government in Australia in planning new towns and urban areas available only in non-peer reviewed reports. The underpinning principles are the recognition of movement corridors and precincts and the need to analyse friction and impact. There are two fundamental requirements in the development of urban areas: (i) to provide for through movement, and (ii) to protect living areas and areas of activity from traffic and its associated safety and environmental impacts. It is not possible to have protection, such as traffic calming, without providing alternative routes for the efficient movement of goods and people. The purpose of this policy tool is to protect local environments from through traffic by creating precincts, and to facilitate through movement by establishing transport corridors. 

 

Precincts have mostly been understood to be neighbourhoods and it is, indeed, one form of precinct, but the interpretation of precincts is broader. Precincts may constitute residential areas, commercial centres, campuses, institutions, and many other land-use associations. What they have in common is a cohesion and quality which allow activities to function within a local environment and with an intrinsic amenity and unifying quality. In New South Wales, state-significant precincts are areas with state or regional planning significance because of their social, economic, or environmental characteristics.

 

Experience of the dynamics of demographic change shows that precincts based on a fixed formula, such as neighbourhoods based on a primary school catchment, create major difficulties when household composition and size change. The economics of local shopping centres also changed when supermarket dominated centres arrived. Precincts may be organic entities but are always part of a larger whole in an ever-changing relationship. There will always be strong linkages with functions and activities beyond a precinct. Adequate provision of interconnections is, therefore, essential.

 

The successful planning of urban areas as precincts and corridors can achieve various objectives. Planning can protect local environments from through traffic. Planning can provide a basis for traffic calming within precincts. It can create local environments with a high level of safety and amenity. Planning can facilitate the planning and development of transport routes for through movement. Importantly, when considering fully autonomous vehicles, planning can provide a basis for integrated design and management of transport routes and their environment. The introduction of a new technology should enhance and improve these basic system concepts.

 

2.3. Understanding Friction and Impact

 

Whilst the distinction between precincts and movement corridors (and the three functional road classifications) is clear, the reality of cities is that they are highly complex when identifying the spatial boundaries of any case study. It is worth pausing a moment to comprehend the challenge of establishing precincts and corridors, as illustrated in an aerial view of the inner suburbs of Adelaide, Australia (Figure 1). This involves defining and addressing issues at the regional, district and local levels. In a future context, improved suatainability is achieved through a greater use of public transport and green modes of transport, but here we address friction and impact when some AVs are present. We need to know more about how to reduce pedestrian incidents in an AV shared environment, such as in Figure 1. This includes reducing exposure to public and private AVs, and autonomous trucks, increasing clarity of these vehicles, and improving visibility for a safer shared space. This checklist, in turn, influences the categorisation of movement corridors from a risk perspective.

 

 

Figure 1. The Complexity of Urban Precincts and Movement Corridors, City of Unley, Adelaide

(Source: Google Maps with text superimposed by H. L. Westerman)

 

Figure 1 summarises a process for arriving at the future readiness stage. The central workspace is detailed but not necessary for a general presentation. It is important to show that there is a context in each case, and these can be quite complex. There is always a present, and an existing, plan for ‘the’ future. The picture immediately raises the question: where are the precincts and corridors? It also is indicative of a process for resolving it: understanding the regional context, the district context and then dealing with any issues of precinct boundaries and corridor types which arise.

 

‘Friction’ (in contrast to ‘impact’) is used to identify and measure the incidence of events and situations affecting the risk of pedestrians to the safe functioning of AVs in a shared space. There are different kinds and levels of friction (Figure 2), and - depending on what we want to achieve – friction can be ameliorated or removed entirely. For example, if some of the corridors need major adaptive work because of frontage friction, some of the businesses now dependent on conventional vehicle access may require relocation into a precinct. In other words, this in-depth investigation may be an opportunity for innovation in grouping autonomous business vehicles. Workshops with stakeholders and community representatives are obviously needed here, as there is a lot at stake the any transition period.

Figure 2. Example of a Type II Corridor Friction and Impact Analysis When Transitioning AVs Into a Precinct

(Source: based on [53])

 

The AV strategy will show what is needed to achieve an optimal relationship between AVs and existing, and future, communities: fix, adapt, transform, or invent, or some combination. Adaptation, transformation, or innovation may vary throughout the urban area and have different time frames. There will be hard decisions on how that can be programmed. ‘Optimal outcome’ is measured in L (short for Level of Service) and maximum speed. A process of securing an overall strategy can be envisaged with priority areas determined on the basis of need and opportunity. Key elements in this process are risk management of corridors, including the effort required to achieve the strategic overall outcome. This needs a citywide authority with a task, a team, resources and a requirement to produce an annual future readiness update. It represents a commitment to a systemic renewal of the city. This mandate is not just for roads and streets, but for precincts and corridors. That is a large and significant commitment which needs public understanding and support.

 

The central message is that the identification methodology for urban structure and corridors must embrace the existing infrastructure and how to get more information on the role, and future, of a certain corridor where there is a problem. This will provide a handle on where modifications should be considered. Figure 3 illustrates the approach needed for a friction and risk analysis for the study area of Unley shown in the photograph of Figure 1 that includes a schematic map of the area, diagrams of Type II corridors illustrating friction and impact, and the strategy based on this analysis [53].

Figure 3. Friction and Risk Analysis for the City of Unley, Adelaide, South Australia

(Source: [53])

 

2.4. Risk Management and Autonomous Vehicles

 

In the case of urban transport there are numerous areas of potential risk that need to be addressed in order to future proof cities. The following list of principles in risk management require attention when detailed investigations of AVs are conducted.

 

 2.4.1 Risk management drives everything

Human error is the main cause of AV accidents. Risk management begins with minimising human exposure to AVs where impact could be serious because of speed. Impact management comes down to visibility and reaction time with speed and distance being the deciding factors. It follows that the contact space needs to minimise the risk of exposure and that AV are recognised by humans.

 

• AVs have their own distinctive presence 

Accident risk between AVs and pedestrians must be reduced towards zero. Colourful, recognisable from afar, distinctive in respect of function, understood by children and octogenarians. Autonomous public transport vehicles can be colour coded too, but the smallest vehicles must be the most distinct and noticeable.

 

• Using precincts and corridors

Within defined precincts pedestrians and cyclists must take priority over AVs and speed limits are one mechanism to lower risk of accidents. Precincts are coherent areas for living, working, recreation and other activities without vehicular traffic passing quickly through them. AVs can be accommodated within precincts proving their speeds are low and there is space and time for pedestrians to respond to vehicles whenever needed. Corridors are for movement between precincts.

 

Corridors come in two basic forms. Type I have no access to abutting land uses and are solely for movement. Type II corridors provide access to property as well as movement for vehicles. With current access, driveways, pavement activities and design, and parking arrangements, visibility of AVs by pedestrians is impaired. There are greater risks when speeds are higher and humans are distracted by frontage activities, or unaware of their immediate surrounds.

 

• Precincts have their own foot-print

Risks of accidents can be reduced when the community in a precinct are involved in rule making. From the type of land use it is possible to determine the demand level and what type of AVs is needed in a precinct, and how these transport demands can be served in a low speed and low risk environment. It is straightforward to establish rules for that precinct and to involve the local community in rule making. For example (as a starting base for a discussion) access courts have a maximum of 10 km/h; access streets have a range of 25 - 30 km/h with light colour markings for AV lanes; and connector streets say 40-50 km/h maximum with darker colours for designated AV lanes and autonomous bus lanes.

 

• Buildings have access courts 

Building forecourts can be designed with people safety in mind. Buildings have access courts where AVs come when called and callers wait and board. There is space and capacity for the transfer of disabled passengers. Access courts are not to be used by service vehicles. Depending on precinct design, an access court can serve several buildings provided there is adequate capacity. There will need to be design standards developed so that precincts and access courts are properly laid out and can function correctly and safely. Autonomous vehicles (public and private) can be designed such that the whole of the kerb-side body opens to allow easy access for passengers and their luggage.

 

• Precincts have their own management system

By putting the onus of precinct management at the local level can contribute to lowering risk of accidents. Precincts are a useful basis for allocating space, managing AVs, providing fast charging access for electric and hydrogen fuel cell vehicles, managing service vehicles and for setting rules. An AV precinct access plan should be prepared before they are implemented. If there is a Precinct Public Body Corporate, they should take on these functions.

 

• Performance for responding to calls requires a local mobility centre

Vehicle and passenger access to and from a mobility hub must be free from obstructions and congestion, and be able to deliver a transport service within, say, two minutes of a call booking. That is a tough call to implement and needs discussion locally. AVs are maintained, charged, cleaned. The centre provides a 24/7 service including for people with special needs. There are connections with regional transport services.

 

• Quality of service

There are risks that AVs will not perform to the service standards required to meet community expectation. Mobility hubs can be inserted in established areas, and also provide commercial and community servicesabove. The service would be so efficient that the need to own, park, operate and service personal vehicles disappears. Local parking codes for new developments can be relaxed and unit cost reduced. Owners can take a share in the Mobility Hub and claim benefits. The precinct community can create a Co Op to operate the mobility hub.

 

The quality of mobility services is central from an efficiency, social, equity and sustainability perspective for the future of the city. Mobility hubs should remain public property, but they can be leased for long-term development with conditions of building approval and operations. With development rights above, they are likely to become a sought-after investment and produce a community return.

 

• Type I corridors (assuming that they have controlled access) can be shared with AVs. 

Risk of collisions along main roads can be reduced through good design. Blue lines can be painted on the pavement to define an AV lane for fully autonomous vehicles with cruise and lane control. If autonomous trucks become prevalent, there is an option to create a separate lane (or carriageway altogether).

 

• Type II corridors need special treatments

Type II corridors are very common in urban areas and require thoughtful design elements to reduce pedestrian – vehicular traffic accident risk. They can have functional and active frontages and are therefore difficult to management with all of the potential pedestrian/vehicle conflicts. Parking manoeuvres and driveways present hazards so Type II corridors are no places for access driveways and parked cars. There can be space for pedestrians and cyclists, but the use of the corridor space must be very clearly designated. Pedestrians and cyclists have their own paths. There will be many pick-up-points on laneways to the rear. There are opportunities for autonomous buses on designated lanes in the movement corridor, but the stops have to be located near intersections so that pedestrians can get across conveniently. 

 

• Risk management plans for selected corridors

Risk management, and optimising AV performance, require that friction be reduced, or, in some cases, eliminated altogether. A draft of the risk management plan should be on exhibition and reviewed at public meetings. Until the plan has been implemented and signed off, AV provisional speeds should be restricted to fit existing conditions and never exceed 60 km/h and pick-up-and drop-off points should be clearly identified and illuminated. There should be a designated AV lane with a strong colour and illuminated signs in place. When the management plan is approved, AV speeds can be raised in accordance with proposals in the plan. Performance is monitored and includes viewing videos of behaviour in different conditions.

3. Results

The previous section has explained the methodology of deploying “friction and impact” in the analysis of road corridors, and the important mapping of issues that have been identified. Based on such findings the problem to address is how do AVs fit into these road corridors, frontage land uses and precincts. Section 2.4 has identified some of the risk factors to consider and some of the risk management tools. In applying the methodology, it is necessary to formulate a strategy plan for implementation, and this is illustrated for the City of Unley. During our deliberations on this matter, it became apparent to us that the new concept of a “mobility hub” was essential in order to successfully transition AVs into cities so as to achieve their potential in complementing public transport services. Section 3.2 elaborates on this future new type of land use. Planning strategies and mobility hubs requires a vision, actions and options (3.3). Finally, several examples of suburbs, precincts and movement corridors are given.

• • Strategy Plan for Implementation

 

To effectively manage existing road corridors with adjacent mixed-use developments requires a strategy plan for implementation that is best explained with an example. The strategy for the study area of the City of Unley is presented in Figure 4. This work was commissioned before we were aware of the changes in transport technology and the potential of fully autonomous vehicles. The built form remains much the same and therefore the process that we introduce in the next section can be used today for studying the impact of and transitioning to AVs.

 

Figure 4. Strategy Proposed for the City of Unley Precincts and Movement Corridors

(Source: [53])

 

Figure 5 is an example from Unley where one of the most complex corridors had strategies to balance the transport functions with a range of friction frontages. There are also public transport nodes. Application of risk management principles presents different levels of performance along the corridor. The outcome is transformation with variable speed and pavement measures. But the big winner is the new hub with TOD (or TOC).

 

Figure 5.  Corridor Strategy for City of Unley, 2002 and 2024 (With AVs)

(Source: H.L. Westerman).

 

• Mobility Hubs

 

We suggest that one of the most significant responses to the advent of AV is to introduce an innovative concept that has the potential to transform perceptions and behaviour about transport - the mobility hub. The mobility hub will be created in precincts where AVs are waiting to be called, despatched, returned to be cleaned, charged, and maintained. Whilst we are unaware of any operational facilities of this kind, we speculate on what they can achieve, their potential benefits, and the potential returns on investment of a mobility hub (Table 1).

 

Table 1. The Concept of a Mobility Hub for Autonomous Road Vehicles

 

Function	Explanation
Mobility Hubs as local plac to connect	They connect with other hubs as local transport nodes in a regional network. They can evolve in a contemporary form of community centres. They become a requirement in local planning schemes and remain in public hands as an investment for the community. When approved and built they can help transform the urban form and become the contemporary, local version of transport-oriented development (TOD, TOC or an amalgam of the now defunct local commercial/retail centres.
What they can achieve	Affordable, accessible, and instant mobility as a service.  Inclusive mobility with opportunities for the disabled, young and old. Available 24/7, always present in the advent of an emergency situation. Reduction in the need to provide long-term and overnight parking spaces. Influences the community mindset about the need for car ownership and a garage with one or two spaces.
Potential benefits	Change the behaviour towards a more sustainable transport system. Invest in the mobility for everyone. Opportunity for families to offset basement parking space in an apartment building with shares in the mobility hub or for the free use of services (up to a capped level). Results in more affordable housing because there is no parking construction. No circulating of waiting cars as mobility hubs are ubiquitous in the city.
Investment and return	Provision of a mobility hub should become an urban planning requirement. The hub is a site with street access; space below for despatch, receive, hold, clean, charge AVs. There is space above for business or community centres with potential for business services dealing with people (e.g. gym, pubs, coffee shops, bars, medical centres). There is potential for drone parcel reception on top of the mobility hub. The development site is offered as a long-term lease with conditions, or an option to form a local CO-OP or sub-lease

(Source: Authors)

 

There is no established planning process for mobility hubs in Australia, but we can work from first principles to suggest a possible approach. First, there needs to be clarity in the preconditions and assumptions for any strategic planning of precincts and mobility hubs. Before delving into strategic options, it's important to grasp a few key points (Table 2). These assumptions relate to knowledge, road safety, legal considerations, dependency on mapping data and uncertainty management.

 

 

 

 

 

Table 2. Strategic Planning Assumptions for Autonomous Vehicles in the City

 

Domain	Strategic Planning Assumption
Knowledge	Autonomous driving technology is still under development in Australia. Mixed traffic with humans will likely continue as a transitional phase.
Safety	Accidents may result fr om erratic human behaviour from pedestrians or cyclists. Human drivers react at least four times slower than autonomous systems. AVs can become safer after accident analyses, advances in programming and AI. The question of how to educate human behaviour when in the environment of a future mobility hub.
Legal Considerations	In accidents, determining who is in control is crucial. If driverless, the manufacturer may be liable; if a human driver is present, they could be considered at fault.
Dependency on Mapping Data	AVs heavily depend on precise, real-time mapping data to navigate and make decisions.
Uncertainty Management	The fast-evolving nature of AV technology suggests the need for a system that starts in a highly secure mode and can adapt with improved performance and acceptance. Managing uncertainty can be achieved by employing rules that are applicable to specific times and locations, providing a practical approach to address dynamic situations.

(Source: Authors)

 

A strategic planning process for precincts (the geographical entity that creates the demand for travel), mobility hubs, and corridors is proposed that involves community engagement through a series of workshops. With the arrival of autonomous vehicles and new forms of transport such as drones or autonomous buses, metros and ferries, the choice of transport mode changes and the planning process must reflect this change. Noting the uniqueness of precincts in terms of future modes available and the kinds of corridors, existing and planned. The outcome of this planning process is a revised strategy plan and action plan that integrates AVs into precincts and mobility hubs. There will be hubs of different scale, but one conceptual map will illustrate thispoint (Figure 6).

 

Figure 6. Conceptual Plan of Mobility Hubs with Different Scales and Primary Functions

(Source: H. L. Westerman)

 

Mobility hubs have the potential to become important elements with future precincts that accommodate autonomous vehicles. The schematic plan in Figure 7 shows the location of a mobility hub surrounding by retail and community activities at the periphery of a precinct. The layout clearly identifies the land-use activity spaces and the movement spaces for all users. The precinct hub can then serve as a ‘fine grain’ interchange system connected to a larger district and regional transit-oriented centre. The mobility hub will become a local transit-oriented centre (LTOC). There will be lots of them - which is a big financial investment. The economics can work because each hub has development rights and a community focus. Although it is also a development and a design challenge, we can foresee a company specially set up to plan, design, lend, build and lease. Furthermore, facilitating seamless transfer through hubs increases public transport use between them. We can shift from an AV to an autonomous bus or metro to avoid congested sections of the city and then transfer to an AV again for the last leg. It is important to test these concepts by developing and building a prototype in consultation with an existing community.

 

 

Figure 7. Example of a Precinct with a Mobility Hub (A Major Mobility Hub would be Connected to Metro or Heavy Rail)

(Source: H. L. Westerman)

 

As we have yet to locate in the literature an illustration of a mobility hub for autonomous vehicles, we have drawn up an indicative plan of its ground floor and vertical layout (Figure 8) and hypothesise on its person traffic generation numbers to illustrate the first steps in a traffic impact analysis. Note in the diagram that there is drive-in drive out to the mobility hub and given in Australia that the road rules are drive on the left, left turn in and left turn out minimises conflicts on the road. Until we have authentic data, we assume 1000 people need about 700 cars per peak hour (equivalent to 12 cars per minute). AVs get full use during the peak demand. Thereafter, there is under-used capacity and vehicles are available for other trip  purposes such as deliveries.

 

Parking demand may not change much overall, but the parking location is changed radically. A little private space may remain in existing buildings and provided in new buildings, but the bulk is now concentrated in the hubs and reserve areas. Coping with 700 cars for 1000 people at peak is a substantial task. The hub could have a large, automated space or a smaller one with holding areas nearby, provided the 2 min performance target is achievable. There is another option for parking in new areas. We can plan a precinct to create an entire interconnected basement. Buildings have their own entity at ground level and above. The precinct basement is owned by the precinct body corporate and leased long term to the mobility hub leaseholder. It also creates an opportunity for a below ground autonomous waste collection system. This option may not be possible in established areas unless there is a proposal for integrated redevelopment.

 

. 

 

Figure 8. (1) Hypothetical Plan of a Mobility Hub for Autonomous Vehicles;  (2) How the Mobility Hub can become a Local Transit-Oriented Development with Autonomous Vehicles; and (3) Tenure Arrangements.

(Source: H. L. Westerman)

 

There is scope for development above such as medical clinics, gym, a pub (no worries about alcohol testing), cafes, offices, library, and community space (Figure 8-2). On top there is an opportunity for air taxis and drone deliveries (Figure 8-3). In certain circumstances, and depending on airspace constraints as designated by air traffic control, the roof of a mobility hub may be suitable for the receipt of drone deliveries. There is an important variant for parking. We could allow waiting AVs to park in Type II corridors or on some streets (as at present vehicles can now), but this is not supported because (a) it is contrary to the principle of risk minimisation, (b) movement corridors are public investments and (c) during the transition phase towards autonomous movement, the parking lane should be used to safely manage mixed conditions by designating lanes. Parcel deliveries at ground level can be provided via an Australia Post machine, or from any authorised delivery service.

 

Finally, there is the question of who owns the mobility hub. We belief that the site itself should be in public ownership with tenants leasing the building (Figure 8-3). The key should be long-term leases for hub-associated businesses and roof top activities subject to performance measures being met. There should be community title for community spaces. For example, there can be a 99-year renewable lease for upper-level development providing that affortable housing is built, and a 40-year lease if the space is commercial.

 

In this paper we have focused on the role of AVs to meet personal trip needs, but we also need to focus on optimising this new technology and fine tune government and industry priorities from an autonomous transport network perspective. Connectivity at the mobility hub offers longer-term prospects in transport mode choice. For example, in Brisbane a metro E bus with high frequency and capacity has been implemented: it could  become autonomous when it has its own right of way and without introducing friction into the movement corridor. Friction typically occurs in high-density people locations where a driver is currently essential. As congestion sets in, the metro E bus must be friction free from people crossing the road: it must have a separate right of way above or below ground. In this future scenario, when public transport is given priority for all origin-destination people movements, we can change the AV trips to redirect the passenger to the nearest hub, seamlessly connect to the nearest metro ,and pick up another AV at a prescribed point of changeover.

 

All of this entails a highly effective and advanced communication system to connect transport service providers and the user. This can achieve mobility management with intra-transport mode changes whenever and wherever is required by the user. We might speculate that a Bureau of Mobility Briefing (BOMB) has been established jointly by government and industry to coordinate travel demand and supply. When a user engages with this new technology and specifies a desired journey from an origin to a destination at a specified time an itinerary is provided on where to change vehicles, arrival destination time, and to notify the passenger on route of any relevant updates. Information on weather conditions in the locality is important for a variety of reasons (appropriate  clothing and wet weather protection) and can warn in advance of flooded roads and precincts that might persuade the user to deter from making that journey.

 

• Managing Autonomous Vehicles in Precincts and Corridors

 

Vision

Future readiness can be described as strategic insight combined with an action plan. It starts with a vision. We suggest that one suitable vision is to increase mobility, reduce travel distances and costs and contribute to a more sustainable transport system with less environmental impact and lower accident rates. This needs to be implemented progressively and cumulatively, while respecting the past and leaving options for the future.

 

Action Areas 

The overall aims of the project must be determined and quantified but as a minimum involve: safety; mobility; accessibility (including economic and social accessibility based on equity); system responsiveness and security. Actions for precincts include delineating precincts; AV performance areas; buildings and spaces to modify; and rules activation. For movement corridors, there are necessary actions for potential AV corridors; risk identification; risk management; speed performance targets; and rules activation. The design of mobility hubs includes concept planning; their status and scope; and how they might evolve as fully autonomous vehicle gain acceptance into the urban transport market.

 

 Options

Level 1:  Fix existing corridor or precinct – with simple adjustments, information sharing, signs, illumination, and vehicle or pedestrian priorities.

Level 2: Adaptation - increase AV visibility, existing space reallocation, existing access points moved where possible, remove on street parking, add bollards and colour pavement for designated autonomous vehicle and autonomous bus lanes.

Level 3: Transformation - applicable to corridors with mixed movement and access functions, provide access lanes, on street parking, pavement activity where the plan is to improve transport performance for AVs. Transformation also includes transitioning to a higher capacity no friction corridor, including redevelopment and higher densities.

Level 4: Innovation - introducing core elements to future proof the city for seamless autonomous movement. Mobility hubs come in this category.

 

There are options for precincts and governance. A local authority may establish precinct committees for advice, and, perhaps, be responsible for implementation of the rules and undertaking any improvements to make that happen. Another model is a formal arrangement, such as a community title. This would require a Precinct Body Corporate (PBC), elected by the precinct community with power to raise levies, control AVs, establish the rules, adapt and reconstruct to enable proper functioning with funding, and to respond to issues which require change. Such a PBC may also be empowered to play a role in establishing and overseeing the management of a local mobility centre, which becomes a “place of connection” in more ways than just mobility, as a symbol of local identity. That has the potential to be transformative in local community building. Some examples of precinct types and movement corridors follow.

 

• Ubiquitous Low-density Residential Precincts with Type III Roads

 

To illustrate the potential of system design, let us consider the different levels of intervention in precincts and corridors. First, in low-density, suburban residential neighbourhoods where dwelling lots have off-street parking, and streets have generous widths, only a level 1 intervention is needed. An example of a functional road hierarchy of streets, footpaths, and cycle paths together with the physical layout of a Canberra suburb, Watson, is shown in Figure 9. The population (in 1976) of 4,261 has a gross residential density of 3.7 dwellings per hectare. 

 

Watson is a classic example of neighbourhood planning at the time, but there has been change. The local centre became little more than one or two local small-scale businesses. The plan allows four precincts but a mobility hub to replace the almost defunct local centre that could cater for all of the local population and satisfy the travel response within a 2-minute criterion. There are driveways but visibility is good. The rules could start at 40 km/h and depending on public response be increased to 50 km/h later. Minimum intervention is required with simple adjustments in this low-speed environment. Lanes for AVs and autonomous buses require distinctive colour paints, as does bike lanes. Pick-up and drop-off points in local activity centres need space allocation, illumination, and signage. The local government (Australian Capital Territory) works with representatives of the community in determining the specifics of the road rules, as an illustration of community consultation for autonomous vehicles.

Watson passes the test because its original design allowed the option of a mobility centre in an excellent location and conforms with the principles of traffic calming and local area traffic management.

A model of the financial viability of a fully autonomous vehicle fleet in Canberra provides strong evidence that under a wide range of car operational characteristics and journey demand levels, such a fleet can provide an extremely high level of service much cheaper than private cars and existing public transport. A personal communication from Kent Fitch at UNSW Canberra points out that fleet of 34,000 fully autonomous sedans can service 1.1 million “on-demand” door-to-door journeys per day, with 95 per cent of journeys starting within one minute of the request being received and do so at fares much lower than the cost of undertaking the same journeys by private car. This initiative would support about 2800 full-time-equivalent jobs and generate an annual surplus of about $125 million (in 2013 prices) - enough to provide free transport for almost 100,000 journeys per day, all without requiring any rate-payer funding. Of course, for the long-term future, an economic evaluation of public transport and fully autonomous taxis would be required based on a life-cycle analysis of vehicle fleet purchase costs, labour inputs, operational costs and maintenance costs.

 

 

 

 

Figure 9. Road Hierarchy and Pedestrian/Cycle Paths in Canberra Suburb of Watson, 1976

(Source: [12, Figure 9.4, p. 211])

 

• High-density Residential and Commercial Precincts

 

This illustration is based on a new high-density precinct (Figure 10). This illustration is based on an existing ‘main street’ in transition.  Commercial activities are experiencing declining fortunes because of access and parking restrictions. However, there are public transport services and a need for affordable housing in medium-density form. It provides an internal access court for picking up and delivering passengers. There is provision for AVs and a fully autonomous bus service in a designated lane for AV’s. Walking, cycling, and e-scooters are other important transport modes for shorter distance travel.

 

 

Figure 10. Conceptual Plan for Linked Precincts where there are Main Streets

(Source: H. L. Westerman)

 

• Type II Corridor Treatments

 

Type corridors come in many forms and are the weak link in a new AV system. There are all kinds of risks and pedestrians are a major cause. Figure 11 identifies the risk-related factors for pedestrians in a Type-II movement corridor. Questions arise about managing the problem without a fundamental overhaul. Removing frontage property access and lanes for commercial vehicles, frontage parking, pavement activity are all in the too hard basket.

 

 

 

Figure 11. Frontage-Related Risk Factors Associated with Pedestrian Behaviour in a Type-II Corridor

(Source: H.L. Westerman) 

 

There are steps in the renewal process of Type II corridors. For example, a trellis and raised planter boxes, combined with the removal of on street parking reduces the risk exposure level considerably (Figure 12). The example is an effective form of adaptation. Raised planter boxes can also clarify pedestrian space without concealing it from AVs. They can be part of the local community garden growing herbs, tomatoes and chillies (note: you may need a body corporate for that). A pergola along footpaths comes with two bonuses: (1) climate proofing with sun protection, and (2) the ‘new economy’ - an opportunity to use the structure for growing oranges and lemons in Queensland and for apples and pears in Tasmania. Developing and implementing a streetscape intervention complements how risk to pedestrians might be reduced by improving visibility and simplifying footpath use. We can add a trellis or other landscape elements to improve pedestrian conditions in the face of increasing heat and glare. It adds value to the pedestrian environment at an implementation cost, but the benefit is a movement corridor that can accommodate faster- moving AVs. The photograph at the top of Figure 12 is a Copley Wolff Design Group custom trellis as part of the 2nd Street District streetscape, in Austin, Texas, USA.

.

Figure 12. Examples of Corridor Risk Management through Streetscape Design

 

• Integrated Redevelopment

 

There are also options in future proofing Type II corridors through integrated redevelopment of land uses and their frontages [6, Fig C-C 14-7]. This is an example of a level 3 intervention that is transformative by involving acquisition (generally by consent) of land, the pooling of land titles, including space at the rear to create a viable new precinct. Landowners get a brand-new apartment in return with an enhanced environment, and a payment for their cost of the changeover. There would be no vehicular access to the front, and fewer spaces for private cars. Everyone gets better and affordable living quarters. With this conversion scheme, the new development is attractive, affordable, and equitable. It changes the appearance of urban areas too (Figure 13). This transformation requires government policies and urban design guidelines to refashion urban precincts with AVs. For each Type II corridor, there need to be assurances that road safety is not an issue, and where there are problems, a risk management plan is formulated. By removing current friction along roads and their frontages – driveways and parking manoeuvres - faster AVs become safe and efficient operations across the city. 

 

Figure 13. Diagrammatic Illustration of Consolidating Sites Along a Type II Road Corridor

(Source: based on [6, Fig C-C, 14-7])

 

In this paper we have focused on the role of AVs to meet personal trip needs, but we also need to focus on optimising this new technology and fine tune government and industry priorities from an autonomous transport network perspective. Connectivity at the mobility hub offers longer-term prospects in transport mode choice. For example, in Brisbane a metro E bus with high frequency and capacity has been implemented: it could  become autonomous when it has its own right of way and without introducing friction into the movement corridor. Friction typically occurs in high-density people locations where a driver is currently essential. As congestion sets in, the metro E bus must be friction free from people crossing the road: it must have a separate right of way above or below ground. In this future scenario, when public transport is given priority for all origin-destination people movements, we can change the AV trips to redirect the passenger to the nearest hub, seamlessly connect to the nearest metro, and pick up another AV at a prescribed point of changeover.

 

All of this entails a highly effective and advanced communication system to connect transport service providers and the user. This can achieve mobility management with intra-transport mode changes whenever and wherever is required by the user. We might speculate that a Bureau of Mobility Briefing (BOMB) has been established jointly by government and industry to coordinate travel demand and supply. When a user engages with this new technology and specifies a desired journey from an origin to a destination at a specified time an itinerary is provided on where to change vehicles, arrival destination time, and to notify the passenger on route of any relevant updates. Information on weather conditions in the locality is important for a variety of reasons (appropriate  clothing and wet weather protection) and can warn in advance of flooded roads and precincts that might persuade the user to deter from making that journey.

 

•  

 

                 

 

 

4. Discussion

Future readiness for AVs is measured by the level of intervention achieved through local risk management. There are four levels of intervention:

1. Fix - minimal, easy, practical; examples: signs; line marking, colour coding.
2. Adaptation - regulatory control and physical modifications: create precincts with local access areas, access courts, designated pick-up points; select corridors as movement routes and modify them through corridor risk management.
3. Transformation - redevelopment with inbuilt risk minimisation; example removing access and parking, Integrated redevelopment to higher densities.
4. Innovation - local mobility hubs - with the prospect of high-speed response time, enhanced connectivity, and behavioural change with economic, sustainable or social consequences. There is a practical benefit of reducing parking requirements in buildings, including residential properties, and improving housing affordability.

 

There are management models associated with each level of intervention. The more embracing or consequential, the more intervention from higher levels of government is required. As with Canberra’s land tenure model, or the role of the Economic Development agency in Queensland (EDQ) working in association with the transport agencies and the development industry to produce outcomes for the Northshore Hamilton precinct, the more integration within the agencies, the more and better funding options will occur, and the sooner the results of transitioning to AVs will be seen. Community participation is central at all levels and procedures will be created as AV planning guidelines are formulated.

 

 

As we are unaware of any practical examples of system design and risk for urban fully autonomous vehicles in precincts of cities, we offer a few insights. Future readiness means that there is a flexible system plan for land uses in place which enables the AVs to start even at a minimal level, with extension and upgrading as resources permit. Since precincts vary globally, careful classifications are essential for context. Investigating corridor profiles on friction and impact is crucial as they establish the rules for AV performance. Areas for priority intervention will be identified, an interim management plan can be put in place, and options discussed with the local community and businesses. Successful adaptation and transformation require collaboration among property owners, developers, and government agencies. Model rules and design guidelines will be necessary, adapting to future research and development. All this will take time but presents an opportunity to rethink the quality and presentation of precinct areas which have changed from their original character.

 

Transitions take place over long periods of time so the risk management framework must be embedded within agile government [54] with its continuous cycle of readjusting goals and objectives and policies and programs against system performance indicators. To make this land-use planning process clearer, we have provided examples at the suburban scale, the precinct level of a city and its movement corridors, noting, of course, that each precinct has its own distinctive context with its own movement corridors (classified into three types).

 

Based on the case studies of AVs in the future urban form in section 4, we can summarise as to the potential contribution of new transport and information technologies to achieve greater sustainability in cities (Figure 13). Vehicles will be powered by renewable energy sources, either by electric batteries or hydrogen fuel cells, thereby eliminating harmful tailpipe emissions. The mobility hub servived by fully autonomous taxi services provides on-demand twenty-four hour services for all giving equity in access to mobility and shifting demand towards road-based and rail public transport, complemented with AI information. This has implications for reducing private vehicle ownership and lowering space requirements for parking. There are further opportunities to develop mobility hubs as transit oriented developments with basement rail systems and aerial services on the roof. AVs will operate in precincts so there are opportunities for community engagement and management. Movement corridors link precincts so risk management plans will be formulated to reduce traffic and pedestrian accidents.

Figure 13. Potential Contribution of Autonomous Vehicles to Urban Sustainability

(Source: Authors)

 

 

There is one more important issue: autonomous transport can become a significant opportunity for rethinking traditional approaches to urban transport planning.  These speculative ideas include: private mobility without the need to own cars; movement corridors are for movement – not for parking vehicles; public transport is the fundamental basis for friction free mass mobility and to achieve sustainable cities; disconnecting a requirement for on-site parking in apartment buildings and introducing a requirement to provide mobility vehicles and services in residential mobility hubs; creation of options for mobility service parking in the basements of adjoining buildings and connected to the hubs; details of travel itineraries provided by a central authority on suitable AV routings, including transfer to inter-city rail and airports, and on any weather warnings; and giving advice on relocation and reconstruction of homes and apartments in response to climate change.

 

If the land-use planning concepts discussed in this paper come to fruition we should speculate on a plausible modal split for fully autonomous private vehicles and taxis, public transport, and other non-motorised forms of transport. Supported by apps with real-time information on alternative modes, their costs and routes, there is likely be be more multi-modal trips with more transfers. Autonomous taxis are already operational so their market share is most likely to expand with more people realising their availability and reliability makes the private ownership of motor vehicles unnecessary. Mobility hubs with shared private fully autonomous vehicles properly financed and managed by a body corporate may be an attractive proposition for some sections of the community, especially with an ageing population. In the case of Australia with its high car ownership and use, it is hard to imagine that shared AVs and AV taxis would make up 30 per cent of the urban travel market with walking, cycling, e-bikes and scooters making up an aspirational 20 percent of the market.

5. Conclusions

In this paper we have “some lamp posts” to illuminate our future: it is a journey and a long one at that. Sustainability acquires a new dimension when a system view is taken, including land use, transport, property, infrastructure, environment, funding, economic and social priorities. In exploring future proofing of cities for change, including new transport technology, there is an extraordinary opportunity to influence how and where vehicles are deployed because of the advances in information technology and AI. The context of travel demand and supply is changing so that autonomous vehicles can influence a shift in behaviour: the need for car ownership; parking provision; public parking and transport space; time and mode of travel; access and equity issues; priorities in transport system provision; and congestion management. There is always the critical question of transitioning to what society wishes to achieve and how it can be done practically, with all the vested property interests, services, spaces, and activities. A smart (and more sustainable) land use/transport system with AVs has the potential to influence trip demand, transport mode and time of travel and to take account of minimising congestion.

 

Future readiness of an urban system can be described as strategic insight combined with an action plan. System specification involves visions, aims, options and design principles. System design involves data requirements, data analysis, levels of policy intervention (of which four can be identified) and operational rules. Practical applications depend on the context of the corridor/precinct under consideration, the extent of interventions, the roles and responsibility of stakeholders, the consultation necessary on actions to be taken and the rules to be promulgated, and the introduction of mobility hubs as an innovation. We believe that fully autonomous vehicles can abe satisfactorily ccommodated in the urban built form, but it must be “horses for courses”. When there are humans around the rules must be AVs operating only in low speed environments. Rules can be applied (after consultation) for each precinct/corridor, valid at the time of entry and exit of these vehicles There also are larger issues which can change how we plan, change, and rebuild our cities.

 

The literature review has demonstrated that, from different disciplinary perspectives, researchers are addressing the challenges associated with new transport technologies and the city, but we have not identified any contributions that focus on the essential building blocks of urban form and function – namely land-use precincts and movement corridors – except, perhaps, by the research conducted on precincts in Singapore [40]. Facilitating seamless transfer through mobility hubs increases public transport use between them, where convenient transfers can be made from an AV to an autonomous bus or metro, and so avoid congested sections and then transfer to an AV again for the final leg of the journey. This will demonstrably improve the environmental sustainability of cities by reducing private vehicle usage. The precinct mobility hub can then serve as a ‘fine grain’ interchange system connected to a larger district and regional transit-oriented centres. Our view is not one of constant expansion or extravagant urban features, but sustainable growth within our long-term capacities, aiming for cities that rely on renewable resources for the long haul, and, significantly, how it is possible to connect with each other – where humans remain in control in an increasingly digitised, and AI driven world.

 

Leadership, informed ideas by other researchers, and new societal behaviour, will contribute to making cities more sustainable and responsive to climate change and affordable living. As with the case of place making in the planning literature, people are placed at the centre of any planning exercise, so stakeholder and public consultations are essential to advance the concepts proposed in this paper. Already, a draft of this paper has been circulated to some of our land-use and transport planning colleagues for comment and critique, including staff at the Department of State Development, Queensland, who have a precinct ripe for a transition to accommodate fully autonomous vehicles. In terms of wider consultation, peer-reviewed published articles provides the forum to engage a wider audience and to stimulate further publications on the topic. Groups are working on this topic, for example, the European Union funded projects on the European Horizon of the Autonomous Driving (SUaaVE - https://www.suaave.eu/4-new-projects-on-the-european-horizon-of-the-autonomous-driving/ ) and the Urban Mobility Lab at MIT (https://mobility.mit.edu/av ). Further advances could be achieved through convening stakeholder workshops in Australia, and in other countries.

 

A direction for further research is a precinct case study to illustrate the principles and processes described in this paper. This would include the formulation of draft urban design guidelines that incorporate fully autonomous transport systems into precincts, and to disseminate this document for critique and comment from government, industry, and community stakeholders. Another direction is to develop a strategic plan with AVs for a precinct. The traffic modelling could apply the Aimsun commercial package for the autonomous vehicle platform [55] or the MATSim microsimulation model [40.  Chapter 9]. Based on a clear understanding of their operational differences, traffic simulation models can be applied to test the interactions of autonomous vehicles with pedestrians at the basement roadways of mobility hubs. It will allow the traffic impact assessment of mobility hubs as a new form of land use. Data collection can be incorporated into existing traffic impact assessment guidelines. Other examples of further research include how high-rise buildings that contain a high percentage of elderly residents can be transitioned into the shared use of AVs and the options to incentivice residents to give up private vehicle ownership.

.

Supplementary Materials: The following supporting information can be downloaded at: www.mdpi.com/xxx/s1, Figure S1: title; Table S1: title; Video S1: title.

Author Contributions: The conceptual work on AVs and the urban form was undertaken by HLW who produced the illustrations. The literature search and methodology were undertaken by JAB who wrote the first draft of the manuscript.  All authors have read and agreed to the published version of the manuscript.”

Funding: “This research received no external funding”

Institutional Review Board Statement: None

Data Availability Statement: No new data were created,

Acknowledgments: The authors acknowledge funding research over the years from the Australia Federal Office of Road Safety, Austroads, and the New South Wales Roads and Traffic Authority (now Transport for NSW). We thank Andrew Lamb, Economic Development Queensland, for sharing information about the challenges of transforming the site of Hamilton Northshore in a precinct for the future. We have sent a draft of this manuscript to some of our academic and professional colleagues and thank the following who have provided comments that have helped improve the final version: Emeritus Professor David Banister, Transport Studies Unit, Oxford University; Andrew Lamb, Economic Development Queensland; Dr Tanvi Maheshiwari, Monash University; Emeritus Professor Kazuaki Miyamoto, Tokyo City University; Professor Akinori Morimoto, Waseda University; Professor Taha Hossein Rashidi, UNSW Sydney; Dr Kam Tara, Urban Research and Planning Pty Ltd., Kobe; and Ms Jasmine Westerman, property manager, Queensland. The authors thank the five anonymous referees for their highly detailed comments that have forced us to rethink our approach and to extensively revise the manuscript.

 

 

Conflicts of Interest: “The authors declare no conflicts of interest.”

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DOI: 10.1080/01441647.2018.1466835DOI: 10.1080/01441647.2018.1466835.

28. Cugurullo, F., Acheampong, R. A., Gueriau, M. and Dusparic, I. (2021) “The transition to autonomous cars, the redesign of cities and the future of urban sustainability”. Urban Geography,42 (6), pp. 833-859. DOI: 10.1080/02723638.2020.1746096.
29. Brovarone, E. V., Scudellari, J. and Staricco, L. (2021) “Planning the transition to autonomous driving: A policy pathway towards urban liveability”. Cities, 108, 102996  https://doi.org/10.1016/j.cities.2020.102996.
30. Manivasakan, H., Kalra, R., O'Hern, S., Fang, Y-H., Xi, Y-F and Zheng, N. (2021) “Infrastructure requirement for autonomous vehicle integration for future urban and suburban roads – Current practice and a case study of Melbourne, Australia”. Transportation Research Part A: Policy and Practice,152, pp. 36-53. https://doi.org/10.1016/j.tra.2021.07.012.
31. Maheshwari, T. and Axhausen, K. W. (2021) “How will the technological shift in transportation impact cities? A review of quantitative studies on the impacts of new transportation technologies”. Sustainability, 13 (6), 3013. https://doi.org/10.3390/su13063013.
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36. Rodríguez-Lora, J.-A., Rosado, A. and Navas-Carrillo, D. (2021) Le Corbusier’s urban planning as a cultural legacy. An approach to the case of Chandigarh”. Designs, 5, 44. https://doi.org/10.3390/designs5030044 .
37. Black, J. (2022) A Short History of Transport in Japan from Ancient Times to the Present. Open Book Publishers, Cambridge, UK. https://www.openbookpublishers.com/product/1536.
38. Malysheva, E. V. (2020) “Impact of automated vehicles on urban form”. IOP Conference Series: Materials Science and Engineering, 753 032013.
39. Utilities One (2023) “The impact of autonomous vehicles on projectsite (sic) design”. Utilities One, 28 August 2023. https://utilitiesone.com/the-impact-of-autonomous-vehicles-on-projectsite-design. 
40. Maheshwari, T. (2020) An Urban Design Response to the Technological Shift in Transportation
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41. Horni, A. Nagel, K. and Axhausen, K. W. (eds) (2016) The Multi-Agent Transport Simulation MATSim. Ubiquity Press, London.
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Author Response File: Author Response.pdf

Reviewer 3 Report

Comments and Suggestions for Authors

Dear Authors,

There are many good aspects to this manuscript, and I would like to acknowledge your considerable contribution to planning for the transition to AVs. This paper could be presented as highly useful case study research based on Adelaide's suburb of Unley, South Australia. There are potentially a number of principles of planning for AVs that are generalizable, that could be derived from this case and through comparison with other cases available in the literature. It would seem to me that this is an area where you have good potential to contribute. However, a substantial reworking of the manuscript would be required. As it stands, there are several deficiencies.

The main problems are that:

A. The paper lacks a sound case for the novelty of the research. Despite the claim in the second sentence of the abstract, there is actually strong evidence in the literature to the contrary. The fact that this claim can be so easily refuted is one of the main reasons for suggesting a change of methodology to theory development via case study research.

B. The research aim is not clearly articulated. This is typically done by outlining a research question. A research question that fits with case study research could be "What are the important city planning principles for transition to AVs?"

C. Background theory is not well defined or discussed. Theory detailing the fundamental principles of city vehicular transport planning by a well cited author would be ideal. I note that the co-author has a textbook in this area and may be able to suggest suitable theoretical background, especially some landmark papers that include principles of vehicular transport planning. Then the manuscript could develop and augment these principles into ones that are in line with a transition to AVs.

D. The method is not clearly described nor is it replicable. The method should be concisely written, it should support the research question and it should be possible for another researcher to get the same result by following the method.

E. Supporting evidence for claims is quite weak. Every time a claim is made, support the claim with a reference from a peer reviewed paper, or at least a logical argument. Perhaps both.

F. There are several sections throughout the manuscript where there are unacceptably long sections copied from other sources. This is unprofessional scholarship and must be addressed before the manuscript can be accepted anywhere. I list the instances individually with comments:

1. Lines 145 to 147 inclusive. Even though quotation marks are used, the convention for these types of passages, where exact wording to convey precise meaning is not so important, is to paraphrase.

2. Lines 154 to 155 inclusive. Even though a citation is given, the lack of quotation marks is unprofessional, but the common convention, again, would be to paraphrase.

3. Lines 174 to 177 inclusive. Several phrases are taken directly from the article "Toward Policies to Manage the Impacts of Autonomous Vehicles on the City: A Visioning Exercise" by Staricco et al without acknowledgement.

4. Lines 186 to 191 inclusive. Similar issue as outlined in item 2.

5. Lines 197 to 200 inclusive. Similar issue as outlined in item 2.

6. Lines 264 to 273 and lines 277 to 288 inclusive. Similar issue as outlined in item 3.

7. Figure 1. Permission may be needed from Google.

8. Figures 2 and 3. Even though you are the author, permission to use these figures might be needed from the sponsor of the report from which they originate.

The best part of this article is the rich information and practical planning guidelines provided by way of case study. It could be developed as a rich and deep illustration of the principles of city planning for AVs via a well described case study.

I wish the authors success with publishing.

Kind regards from your reviewer.

Comments on the Quality of English Language

Some minor spelling issues were detected, so proof-reading the manuscript as the final step is recommended.

Author Response

please see the attachment

Author Response File: Author Response.pdf

Reviewer 4 Report

Comments and Suggestions for Authors

The theme of the paper is innovative and probably suitable for this journal provided that the contribution of AVs in the sustainability of an urban environment is more clearly presented. The following comments need to be considered during the revision stage:

1_ First, the reviewer is confused about which is the correct type for this paper; an article, a review, or a perspective? Please consult the editorial office.

2_ In the last three paragraphs of the introduction, the authors attempt to address the originality of their paper. However, a clear objective statement is missing. What is actually being investigated? Please mention it clearly at the end of the introduction.

3_ One way to increase the sustainability in urban road environment and simultaneously improve the road safety performance is to transform signalized intersections into roundabouts that are quite popular in Australia. The reviewer would like to see some relevant discussion points, i.e., https://doi.org/10.3390/vehicles6010019

4_ Please enlist specific recommendations about how governments and urban planners can push towards adaptivity and innovation in the domain of AV inclusion in an urban environment.  

5_ Current challenges about the interaction of AV and conventional vehicle fleet is absent. Please try to elaborate with the impact of speed, geometric road design, surface condition status, etc.

6_ Please improve and adapt the structure of the paper, e.g., the title of section 2, line 104, is irrelevant to your content.

7_ Make sure all figures and headings are part of your own work, or else cite them properly. Make the fonts homogenous. Figure 10 has another numbering (i.e., 6). Please fix such issues.

8_ Overall, language revisions are needed within the text, to increase its readability. The format is outdated. Please fix it. 

Comments on the Quality of English Language

Revisions are needed.

Author Response

please see the attachment

Author Response File: Author Response.pdf

Reviewer 5 Report

Comments and Suggestions for Authors

1. please add more keywords related with method used in your study.

2. Please carefully proofread the manuscript for the purpose of readability. E.g., it is very difficult to follow sentences from line 23 to line 29, which was too long to understand.

3.  The figure 1 title was too long, while higher resolution image for figure 2 was in need.

4. The authors were recommended to add more explanations about model used in the study. More specifically, in section 2 add more theoretical explanations.  

5. The following studies were recommend to be properly cited: [1] Efficiency of DECA on ship emission and urban air quality: A case study of China port[J].Journal of Cleaner Production, 2022.DOI:10.1016/j.jclepro.2022.132556. [2] Quantifying Arctic oil spilling event risk by integrating an analytic network process and a fuzzy comprehensive evaluation model, Ocean & Coastal Management, vol. 228, p. 106326.

Comments on the Quality of English Language

English can be improved.

Author Response

please see the attachment

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors The authors have made a much better effort here to produce a more logical and easier to read paper. I have read the new paper from beginning to end and believe it is getting close to being recommended for publication. Before this can happen, the authors need to address the following key points and editorial problems. As I have spent so many hours on dealing with this paper, I request that the response to these points be given systematically, point by point, as provided to them, with what and where changes have been made citing each point, line number, figure or table, so I can see quickly where the changes have been made. Non-editorial/substantive Line 55: Parking crossovers represent a major risk to pedestrians, especially children and other vulnerable people. Line 132: Strange that there is nothing about human safety. Line 214: Should you not be talking about accessibility primarily, rather than mobility per se? Table 1: Quality of service offered by AVs. This can only happen where the alternatives are such that they mitigate against growing and unachievable demand for AV private mobility. If not the fleet of AVs required to meet demand would grow and grow to meet the level of current car use, and we would be back to the old paradigm of essentially car-dominance, just a different technology. Line 250: The paper up to now is definitively about Australia so a clear statement at the beginning is needed to say that all the suggestions, discussion etc are based on Australian perspectives but that the generic principles can perhaps, with due care to local conditions, be more widely applied. Table 2 under Uncertainty Management: There remains the issue of how programmers of AVs make moral decisions about how an AV should react in an emergency with pedestrians and cyclists. Does it opt to injure or kill the latter or does it opt to protect its own occupants. Can it be programmed to do both? Very difficult wicked problem. Line 261 not just autonomous but also non-autonomous Line 267 (paragraph) This worries me. Are the authors suggesting that electric privately owned vehicles will become so attractive with renewable energy that we just have a simple transition of the excessive car fleet of today to electric vehicles, or are they saying that their vision of shared AVs and AV taxis with radically reduced private car ownership (electric or otherwise) will just be greatly enhanced by electric propulsion through renewably generated electricity? This needs to be clarified, because if the former it shoots their vision in the foot. Figure 1: Mode shift remains vague and more words need adding here. Mode shift to PT, and NMM would be appropriate. The AV vision in this paper should be a mopping up operation to cater for whatever trips that are leftover than cannot be satisfied by the PT and NMM, not an opened-ended, supply side expansion scenario for AV mobility. ALSO---transport oriented development not fixed in figure. Figure 5: Are type II roads really having 80 km/h or 90 km/h as per the right- hand part of this diagram. I cannot envisage any Type II road as in Figure 4 possibly accommodating these kinds of speeds. Are the authors really sure about this? Think of Melbourne inner city with all its Type II roads...do cars speed along them at 80 or 90 km/h. Well maybe so, but such drivers need to be sanctioned or the road made impossible to achieve such speeds. Line 353: What are S-Lanes? Line 408: Can the authors address how shared AVS or taxi AVS would be able to meet the demand for private motorised mobility in a suburban setting like this which is currently dominated by cars. Probably 80 to 90 percent of all daily trips by cars. How could this situation achieve suppressed private car ownership and more limited shared AVS and taxis to meet demand? Would not AVs have to simply cater for existing high levels of car use? Figure 11: PuDo is an unfortunate acronym when combined with a precinct dog walk and wheel way. I honestly thought when first seeing it that it was linked:-) Sorry, could not resist that one!! Line 451: and presumably enhance the economic attractiveness of businesses due to increased pedestrian attractivity. Line 462: is there any public transport and what is the role of walking and cycling in this example? I only see talk about cars and private mobility here, yet there must be potential for more sustainable modes too? Line 486: Rail modes are ideally suited to the type of land use and vision implied here. Why are they not mentioned? Indeed, the use of TOD IMPLIES rail because if you look at the literature on TOD it is virtually NEVER solely bus-based, neither conventional nor autonomous, and only sometimes BRT (e.g. Curtiba, Bogota). Figure 16: This figure has not been revised to show transit-oriented development and not transport-oriented development. BUT the most glaring admission in this TOD is the failure to mention any public transport and especially no mention of any urban rail which simply would have to underpin the kind of public transport demand that this density and mixed land use would generate. Line 557: and walking and cycling. There is also an electric revolution in bikes at present (not just cars), especially in Europe so one would think that part of this vision would be e-bikes or so called pedelecs, which are radically changing people's ability to choose a bike for more trips. The authors are only concerned with electric cars which is not complete in my view. Figure 17: Still transport-oriented development. Needs to be changed to be consistent. The figure still is biased towards private mobility in AVs and so does not connect very well with the earlier descriptions. Final comment: A key thing that I think is missing from the paper that would seal its sustainability credentials is to suggest a vision for modal split. The authors have stressed throughout the whole paper the critical nature of data. Modal split is probably the most basic piece of data that reveals a city's transport priorities. We all know that modal split data are available across the world for whole cities and even parts of cities. At present in Australia total daily trip by cars are still up in the 80% or higher level, with a meagre 20% or less by PT and NMM. This is not sustainable even with EVs or AVs. Surely the authors have some view about where this should sit in the future. Would 50% by cars (i.e. in shared AVs or AV taxis, as in their vision of radically reduced car ownership), be a fair position and the remaining 50% by the other modes? My overall impression is that the authors are a bit grudging in their commitment to genuine sustainable transport and rather see a future of still high private mobility but in AVs and EVs designed to solve sustainability problems in transport, with a secondary role for other modes. For genuine sustainability, which is what this journal prides itself on, I think the authors should be more transparent about their genuine commitment to sustainable transport. I know that modal split is peculiar to specific locations and varies, but the paper is prepared to speculate spectacularly about AVs and EVs in the future, so I don't see it as a big stretch or ask to speculate on a vision for future modal splits. And the PT vision is still very bus-biased which does not at all match with their more radical mobility hubs. Any search of the literature will clearly show that the most significant TODs have to be primarily rail based to cope properly with demand and provide a genuine speed advantage.

 

Comments on the Quality of English Language Editorial Line 134: traffic Line 137 remove a "to" Line 184 should specify Australian State Governments Line 212: What is the empty table? Table 2 under Safety - the word "near" is missing" Line 260: dominated Figure 2: the second block in red is cut-off and needs fixing. Figure 3: Captions not correct...photos are Figure 4 Line 300: superfluous full stop. Line 307: the missing before New Line 308: examples after Safety. Line 315: have not has and missing full stop. Figure 6 resolution is poor Line 390. Figure 9 not 10 Line 451: 13 not 12 Figure 13: Still no location for second photo and it is vertically compressed I think. Table 3: What they can achieve: differently-abled not disabled which is no longer acceptable. Line 484: their not its Line 565: and not an Line 571: in not into

 

Author Response

Response to Reviewers

Reviewer Comment	Authors’ Response
Reviewer 1 The authors have made a much better effort here to produce a more logical and easier to read paper. I have read the new paper from beginning to end and believe it is getting close to being recommended for publication.	In addition to responding to specific criticisms, parts of the paper have been reorganised (see tracked changes) – notably the first paragraph to the introduction making it clearer that the originality is about land-use planning; an insert to Section 3 that introduces that section; a new figure 6 illustrating mobility hubs by scale/function; and potential contribution of AVs (now fig. 13) into Discussion section
Non-editorial/substantive Line 55: Parking crossovers represent a major risk to pedestrians, especially children and other vulnerable people.	Not found at Line 55
Line 132: Strange that there is nothing about human safety.	Corrected at line 126
Line 214: Should you not be talking about accessibility primarily, rather than mobility per se?	The literature cited does not talk about accessibility but we have added it into line 216 “…to improve accessibility.
Table 1: Quality of service offered by AVs. This can only happen where the alternatives are such that they mitigate against growing and unachievable demand for AV private mobility. If not the fleet of AVs required to meet demand would grow and grow to meet the level of current car use, and we would be back to the old paradigm of essentially car-dominance, just a different technology.	We accept the point about car dominance with the AV technology instead, but this is certainly not the future we envisage. AVs are not a substitution for current vehicle technology because AVs come with new AI and communication technology. Mobility hubs are essential to keep them off the street (except when in use) and connect users to public transport. They can serve human needs of all ages better. They save money as people do not have to own a vehicle that is substantially underused by many owners. There is enhanced safety through corridor risk management and reduced on street parking. The system potentially has a new level of integrated urban transport management.   We have added: “They connect with other hubs as local transport nodes in a regional public transport network that is appropriately funded”.
Line 250: The paper up to now is definitively about Australia so a clear statement at the beginning is needed to say that all the suggestions, discussion etc are based on Australian perspectives but that the generic principles can perhaps, with due care to local conditions, be more widely applied.	This is an important point. The title has been changed to reflect the contents more accurately: Preparing for Fully Autonomous Vehicles in Australian Cities: Land-use Planning Adapting, Transforming, and Innovating The Introduction now includes: “The analysis of “friction and impact” is based on our previous research into Australian cities and suburbs where driving is on the left-hand side of a road, and this provides a starting point for a risk-based approach to land-use planning for future cities with AVs”.
Table 2 under Uncertainty Management: There remains the issue of how programmers of AVs make moral decisions about how an AV should react in an emergency with pedestrians and cyclists. Does it opt to injure or kill the latter or does it opt to protect its own occupants. Can it be programmed to do both? Very difficult wicked problem.	Analysis of California accidents involving AVs suggest that 70 percent of injuries are sustained in the vehicle and 30 percent involve other road users. AV manufacturers are aware of this and will strive to improve the safety programs. We are no experts on these matters but Table 2 are a series of assumptions and so we have stated: “AVs can become safer after accident analyses, advances in programming and AI. The question is how to educate human behaviour when in the environment of a future mobility hub”.
Line 261 not just autonomous but also non- autonomous	Line 263 reads: “A dominant theme in the literature is speculation about the impacts of fully autonomous vehicles (and traditional vehicles) at the metropolitan scale [33]”.
Line 267 (paragraph) This worries me. Are the authors suggesting that electric privately owned vehicles will become so attractive with renewable energy that we just have a simple transition of the excessive car fleet of today to electric vehicles, or are they saying that their vision of shared AVs and AV taxis with radically reduced private car ownership (electric or otherwise) will just be greatly enhanced by electric propulsion through renewably generated electricity? This needs to be clarified, because if the former it shoots their vision in the foot.	We are merely summarising what the literature says the literature. Our vision for AVs is reduction in private vehicle ownership and greater use of AV taxis especially to mobility hubs well served by public transport.
Figure 1: Mode shift remains vague and more words need adding here. Mode shift to PT, and NMM would be appropriate. The AV vision in this paper should be a mopping up operation to cater for whatever trips that are leftover than cannot be satisfied by the PT and NMM, not an opened-ended, supply side expansion scenario for AV mobility.	Figure 1 does not imply an open-ended, supply side expansion scenario for AV mobility: it addresses what to do with the AVs that are present in that corridor. The main point is the problem of defining corridors and precincts However, we have added at line 391: “In a future context, improved sustainability is achieved through a greater use of public transport and green modes of transport, but here we address friction and impact when some AVs are present”.
ALSO---transport oriented development not fixed in figure.	We hope we have corrected this throughout the manuscript
Figure 5: Are type II roads really having 80 km/h or 90 km/h as per the right- hand part of this diagram. I cannot envisage any Type II road as in Figure 4 possibly accommodating these kinds of speeds. Are the authors really sure about this? Think of Melbourne inner city with all its Type II roads...do cars speed along them at 80 or 90 km/h. Well maybe so, but such drivers need to be sanctioned or the road made impossible to achieve such speeds.	Fig 5 shows an AV dedicated lane at 50 km/hr
Line 353: What are S-Lanes?	Traffic management technique with line markings that eliminate on-street parking from the kerbside line in order to create a right-hand turning lane at a traffic -controlled intersection on a main road. However, there is no reference now to S-lanes
Line 408: Can the authors address how shared AVS or taxi AVS would be able to meet the demand for private motorised mobility in a suburban setting like this which is currently dominated by cars. Probably 80 to 90 percent of all daily trips by cars.                                   How could this situation achieve suppressed private car ownership and more limited shared AVS and taxis to meet demand? Would not AVs have to simply cater for existing high levels of car use	Not found at Line 408 but Line 752. We have addressed this in another paper, so the explanation is given here A model of the financial viability of a fully autonomous vehicle fleet in Canberra provides strong evidence that under a wide range of car operational characteristics and journey demand levels, such a fleet can provide an extremely high level of service much cheaper than private cars and existing public transport. A personal communication from Kent Fitch points out that a fleet of 34,000 fully autonomous sedans can service 1.1 million “on-demand” door-to-door journeys per day, with 95 per cent of journeys starting within one minute of the request being received and do so at fares much lower than undertaking the same journeys by private car. This initiative would support about 2800 full-time-equivalent jobs and generate an annual surplus of about $125 million (in 2013 prices) - enough to provide free transport for almost 100,000 journeys per day, all without requiring any rate-payer funding. Of course, for the long-term future, an economic evaluation of public transport and fully autonomous taxis would be required based on a life-cycle analysis of vehicle fleet purchase costs, labour inputs, operational costs and maintenance costs.   Fitch’s simulation supports view that AVs can suppress private ownership
Figure 11: PuDo is an unfortunate acronym when combined with a precinct dog walk and wheel way. I honestly thought when first seeing it that it was linked:-) Sorry, could not resist that one!!	We acknowledge the humour
Line 451: and presumably enhance the economic attractiveness of businesses due to increased pedestrian attractivity.	Activity
Line 462: is there any public transport and what is the role of walking and cycling in this example? I only see talk about cars and private mobility here, yet there must be potential for more sustainable modes too?	Not line 462. At line 793 we have added: “. Walking, cycling, e-bikes, and e-scooters are other important transport modes for shorter distance travel”.
Line 486: Rail modes are ideally suited to the type of land use and vision implied here. Why are they not mentioned? Indeed, the use of TOD IMPLIES rail because if you look at the literature on TOD it is virtually NEVER solely bus-based, neither conventional nor autonomous, and only sometimes BRT (e.g. Curtiba, Bogota).	Not486 metro mentioned on line 627 and in figure 6.
Figure 16: This figure has not been revised to show transit-oriented development and not transport-oriented development.  BUT the most glaring admission in this TOD is the failure to mention any public transport and especially no mention of any urban rail which simply would have to underpin the kind of public transport demand that this density and mixed land use would generate.	Not fig. 16 but fig 8 but title corrected to transit-oriented development       See response at line 793 above
Figure 17: Still transport-oriented development. Needs to be changed to be consistent. The figure still is biased towards private mobility in AVs and so does not connect very well with the earlier descriptions.	Figure 7 may appear biased towards private mobility but this is an example of a lower-order hub. Higher-order mobility hubs can be built around metro or heavy rail stations as implied by the new title to Fig. 7
A key thing that I think is missing from the paper that would seal its sustainability credentials is to suggest a vision for modal split. The authors have stressed throughout the whole paper the critical nature of data. Modal split is probably the most basic piece of data that reveals a city's transport priorities. We all know that modal split data are available across the world for whole cities and even parts of cities. At present in Australia total daily trip by cars are still up in the 80% or higher level, with a meagre 20% or less by PT and NMM. This is not sustainable even with EVs or AVs. Surely the authors have some view about where this should sit in the future. Would 50% by cars (i.e. in shared AVs or AV taxis, as in their vision of radically reduced car ownership), be a fair position and the remaining 50% by the other modes?	Vision for modal split is covered in discussion
My overall impression is that the authors are a bit grudging in their commitment to genuine sustainable transport and rather see a future of still high private mobility but in AVs and EVs designed to solve sustainability problems in transport, with a secondary role for other modes	Whilst the reviewer is entitled to that impression, the main thrust of the paper is about land-use planning to accommodate the inevitable introduction of AVs into the urban fabric. Whist AVs are not seen as a major driver of sustainability, there potential contribution is now summarised in the Discussion Section in Fig 13. Metros and heavy rail are mentioned where relevant in mobility hubs
I think the authors should be more transparent about their genuine commitment to sustainable transport. I know that modal split is peculiar to specific locations and varies, but the paper is prepared to speculate spectacularly about AVs and EVs in the future, so I don't see it as a big stretch or ask to speculate on a vision for future modal splits.	If the land-use planning concepts discussed in this paper come to fruition we should speculate on a plausible modal split for fully autonomous private vehicles and taxis, public transport, and other non-motorised forms of transport. Supported by apps with real-time information on alternative modes, their costs and routes, there is likely be be more multi-modal trips with more transfers. Autonomous taxis are already in operation so their market share is most likely to expand with more people realising their availability and reliability makes the private ownership of motor vehicles unnecessary. Mobility hubs with shared private fully autonomous vehicles properly financed and managed by a body corporate may be an attractive proposition for some sections of the community, especially with an ageing population. In the case of Australia with its high car ownership and use, it is hard to imagine that shared AVs and AV taxis would make up 30 per cent of the urban travel market with walking, cycling, e-bikes and scooters making up an aspirational 20 percent of the market.

Comments on the Quality of English Language

 

Editorial Line

 

Based on the master manuscript that the publishers sent us the following editorial lines do not match. Hopefully our final proof reading has picked up all minor errors.

 

 134: traffic Line 137 remove a "to" Line 184 should specify Australian State Governments Line 212: What is the empty table? Table 2 under Safety - the word "near" is missing" Line 260: dominated

 

Figure 2: the second block in red is cut-off and needs fixing. Fig 2 is complete

 

Figure 3: Captions not correct...CORRECTED

 

photos are Figure 4 – WE DO NOT UNDERSTAND THE COMMENT AS THERE IS NO PHOTO

 

Line 300: superfluous full stop. Line 307: the missing before New Line 308: examples after Safety. Line 315: have not has and missing full stop.

 

Figure 6 resolution is poor – ORIGINAL IS SHARP – PERHAPS EDITORS CAN ENLARGE FIG 6

 

Line 390. Figure 9 not 10  - ALL FIGURE NUMBERS NOW CORRECT

 

Line 451: 13 not 12 Figure 13:

 

Still no location for second photo and it is vertically compressed I think. LOCATION ADDED TO FIGURE The lower photograph in Figure 11 is that of Sherwood Road, Toowong in Brisbane, Australia. Yes Figure had been compressed

 

Table 3: What they can achieve: differently-abled not disabled which is no longer acceptable. No Table 3 in revision

 

Line 484: their not its Line 565: and not an Line 571: in not into

Reviewer 3 Report

Comments and Suggestions for Authors

Dear Authors,

Thank you for your response which, in the main, was adequate. I write to you with a single issue that remains unresolved and speaks to your own reputations and that of the esteemed journal. The second sentence of the abstract remains problematic. I urge the authors to write in terms of probabilities or likelihoods. Equally, I suggest the authors apply qualifications to their arguments. For example, do the authors have unfettered access to all of the research undertaken by Google and Tesla, much of which could be protected by non-disclosure agreements. Did the authors search the journals written in Chinese? I respectfully request the authors to modify the language accordingly.

Kind regards.

Author Response

No comments were received

Reviewer 4 Report

Comments and Suggestions for Authors

No comments. 

Comments on the Quality of English Language

Moderate changes. 

Author Response

Response to Reviewer 4

 

Comments and Suggestions for Authors

No comments. 

 

Comments on the Quality of English Language

Moderate changes. >>>> These have been addressed

 

Reviewer 5 Report

Comments and Suggestions for Authors

I am not satisfied with revisions. 

Comments on the Quality of English Language

English can be improved.

Author Response

 

Reviewer 5

Comments and Suggestions for Authors

I am not satisfied with revisions. >>>> Unless this reviewer can be more specific in the criticisms, the authors are unable to respond.

 

Comments on the Quality of English Language

English can be improved.>>>>> These have been addressed

 

Comments and Suggestions for Authors

1. please add more keywords related with method used in your study.>>>>>>>>keywords added: Keywords: Autonomous vehicles; land-use planning; road friction and impact risk assessment; mobility hubs with autonomous vehicles

 

2. Please carefully proofread the manuscript for the purpose of readability. E.g., it is very difficult to follow sentences from line 23 to line 29, which was too long to understand.>>>>>Proof reading undertaken. The first paragraph now reads as:

According to Duarte and Ratti [1], autonomous vehicles “offer the first opportunity to rethink urban life and city design since cars replaced horse-powered traffic and changed the design of cities for a hundred years”. Self-driving cars (AVs) are already being trialled in the field, autonomous vehicles are offering taxi services in San Francisco and Los Angeles, California, and Toyota’s Woven City near Shizuoka, Japan, will have people and fully autonomous vehicles mixing on surface roads. We suggest that as this vehicle technology matures there are opportunites for a new level of integrated land-use and transport management with the modification of road frontages, the introduction of multi-modal mobility hubs, and advances in AI and communication technology. The importance of land-use planning to complement a transition to autonomous vehicles is demonstrated in this paper.

 

3. The figure 1 title was too long, >>>>The title is succinct

while higher resolution image for figure 2 was in need. >>now corrected

4. The authors were recommended to add more explanations about model used in the study. More specifically, in section 2 add more theoretical explanations.>>>>> We have added where details can be found in reference 6 in the Introduction

The analysis of “friction and impact” is based on our previous research into Australian cities and suburbs where driving is on the left-hand side of a road, and this provides starting point for a risk-based approach to land-use planning for future cities with AVs. Whilst fieldwork with video cameras recording all personal and vehicle interactions in the defined roadspace was deployed to establish friction and impact, advances in data collection and systems models would be now a more appropriate methodology.

 

and the following in Section 2.3.

Once a study area has been identified (and this is not without its challenges as Figure 1 shows) data collection can commence. A full explanation of the fieldwork necessary to determine friction and impact in a movement corridor is contained in our previously published research, such as reference [6]. We used video-camera recordings to observe individual interactions amongs vehicles, other road users and pedestrians and analysed delays and potential conflicts in the road space. This was complemented with field measurements of road traffic noise at receptor points and of ambient air quality (noting that systems models can be used to make estimates providing speeds and the composition of vehicle types is known). This information is superimposed on land-use maps to identify potential locations that require planning intervention, as illustrated in Figure 2.

5. The following studies were recommend to be properly cited: [1] Efficiency of DECA on ship emission and urban air quality: A case study of China port[J].Journal of Cleaner Production, 2022.DOI:10.1016/j.jclepro.2022.132556. >>>>>>Emissions are one of the impact factors, but we do not go into details of modelling air quality as it is beyond the scope of our paper (AVs do not have tail-pipe emissions and a working assumption for the future is that the grid will be supplied by renewable energy).

[2] Quantifying Arctic oil spilling event risk by integrating an analytic network process and a fuzzy comprehensive evaluation model, Ocean & Coastal Management, vol. 228, p. 106326.>>Outside the scope of our literature search

 

Comments on the Quality of English Language

English can be improved.>>>>>>> These have been addressed (see response to reviewer 1).

Round 3

Reviewer 1 Report

Comments and Suggestions for Authors

Final Comments

This paper has been basically re-written again with a huge amount of red track changes text, so providing a proper final comment has proven more time-consuming and difficult than I was expecting, even given the cover letter explanations. Notwithstanding, I think the paper as currently revised is a quantum leap better than what was originally submitted.

Incidentally, the line numbers quoted in my last review are precisely where the comments were applicable, so I sincerely hope that I was given, at that time, the latest version. The version I received was at the request of MDPI to the authors because I pointed out that the cover email/letter from the authors at that time referred to an attached paper, which simply was not attached, so they were written to in order to ensure that I have the correct and latest version to look at again.

Given the extent of new material, or at least claimed new material in the paper, it is unfortunately necessary to point out some final changes, before it can be published.

Remaining substantial comments (based on the line numbers of the new paper I was given)

1.      The first use of strata manager seems to be at line 139. Unfortunately, this is a peculiarly Australian term which I personally understand, but international readers would not necessarily know. Then on Line 239 the concept of strata titles is explained. So there needs to be some rearrangement needed here to ensure that at its FIRST appearance in the paper people understand.

2.      Line 263 it is universally claimed that if traffic calming is introduced then alternative routes need to provided (I do not know if this means new road construction or modification/upgrading of existing roads). In any case it is a blanket claim that does not take into account that throughout the world there are repeated cases in cities of trip-de-generation in the face of removal of road capacity…a lot of traffic simply disappears and the claimed alternative routes simply are not needed. The tearing down of the massive freeway in Seoul to create a river boulevard, the creation of Swanston Street public transport mall in Melbourne where none of the feared traffic chaos on surrounding streets occurred, demolition of the Embarcadero in San Francisco, pedestrianisation of German city centres where studies were done showing 70% of existing traffic vaporised and it did not show up on any surrounding streets. I think that the paper needs to acknowledge that is far from a blanket rule that is claimed.

3.      Line 531: In my review of the original paper, I pointed out the problematic nature of the 700 AV cars/1000 persons, especially given Australian cities today do not even reach this level of car availability through private ownership. Since the paper is claiming sustainability advantages it is a little hard to understand why such an extraordinary level of car availability would be needed. BUT MORE THAN THIS, this level of AV car availability is proposed for the authors’ MOBILITY HUB, which is their premier, quintessential example of reduced car use, sustainable mobility, reduced parking, etc etc. So, I fail to see if mobility hubs are going to enhance public transport use, reduce car use, reduce parking and make NMM more attractive, why on earth such high levels of cars (more than currently is the case in Australian cities with conventional cars, or indeed most cities), would be needed. To me it simply does not make sense. Furthermore, I do not understand why the authors, having responded to the original comment, by complete removal of this idea, it suddenly finds it way back in. Are the two authors not communicating correctly with each other, perhaps? 

4.      Lines 720-728 repeat exactly from earlier in the current paper. The authors need to decide where this text belongs and only use it once.

Finally, in the cover letter, the authors provide the following block of text, which is their response to the last substantive comment of mine in their cover letter. The text is meant to be inserted in the paper. However, the text is nowhere to be found.

If the land-use planning concepts discussed in this paper come to fruition we should speculate on a plausible modal split for fully autonomous private vehicles and taxis, public transport, and other non-motorised forms of transport. Supported by apps with real-time information on alternative modes, their costs and routes, there is likely be be more multi-modal trips with more transfers. Autonomous taxis are already in operation so their market share is most likely to expand with more people realising their availability and reliability makes the private ownership of motor vehicles unnecessary. Mobility hubs with shared private fully autonomous vehicles properly financed and managed by a body corporate may be an attractive proposition for some sections of the community, especially with an ageing population. In the case of Australia with its high car ownership and use, it is hard to imagine that shared AVs and AV taxis would make up 30 per cent of the urban travel market with walking, cycling, e-bikes and scooters making up an aspirational 20 percent of the market.

Additionally, in this text they say: “…it is hard to imagine that shared AVs and AV taxis would make up 30 per cent of the urban travel market with walking, cycling, e-bikes and scooters making up an aspirational 20 percent of the market”.

Do they mean it is NOT hard to imagine? In any case this text needs to be inserted in the paper.

Editorial comments

Line 49 “ a starting point”

Line 173: and the creation

Line 185 is not ais

Line 373 providing not proving

Line 376 corridors are movement spaces

Line 383 is involved not are involved

Line 393 I have pointed out on two occasions that the term “the disabled” will get the authors (and the journal) into hot water. It is now “differently-abled” if I am up to date. As early as 1993 or before, "the disabled" was black-banned, and it became “people with disabilities”…now even this term is forbidden too. This problem is also in Table 1…last line on p.14.

Line 561 who should MANAGE the mobility hub…

Line 561 We BELIEVE that not belief.

Line 579 I strongly suggest rec-considering the acronym BOMB in the current global political environment. It is a bit insensitive.

Line 624/5 – problem with sub-heading

Line 652 that a fleet.

Line 859 an exemplar not a exemplar.

If these final fix ups are completed properly, then I recommend publication.

Comments on the Quality of English Language

Still editorial minor issues as listed in my comments.

Author Response

Response to Reviewer 1

First of all, the authors acknowledge the time and patience taken by this reviewer in his/her painstaking critique of our three drafts of the manuscript.We started with an idea, and it evolved into a system with a conceptual package.  The persistent criticisms reinforced and clarified the idea for us, and we hope that all of the errors have been removed (see attachment manuscript). Please note that even after we produced a final check still picked up a few more errors in expression.

Remaining substantial comments (based on the line numbers of the new paper I was given)

1. The first use of strata manager seems to be at line 139. Unfortunately, this is a peculiarly Australian term which I personally understand, but international readers would not necessarily know. RESPONSE It is at line 129 where we have added “In multi-occupancy buildings, strata title, or community title (UK, commonhold; USA, Homeowners Association) to individual premises is a common legal arrangement. These buildings are managed by a body corporate comprising representatives of property owners with an elected chairperson, or with a professional building manager.”

 

Then on Line 239 the concept of strata titles is explained. So there needs to be some rearrangement needed here to ensure that at its FIRST appearance in the paper people understand. RESPONSE. This is explained at line 129.

Line 263 it is universally claimed that if traffic calming is introduced then alternative routes need to provided (I do not know if this means new road construction or modification/upgrading of existing roads). RESPONSE; The following clarifies this. There are two fundamental requirements in the development of urban areas: (i) to provide for through movement, and (ii) to protect living areas and areas of activity from traffic (called in Australia “rat-running”) and its associated safety and environmental impacts. Traffic calming in residential areas (local area traffic management in Australia) aims to deter through traffic by the implementation of various traffic control devices, thereby encouraging vehicles to take surrounding major or sub-arterial roads. A full explanation can be found in Black, J. (2023) “Transport Institutions and Organisations in the Formulation of Policies for Australian Local Area Traffic Management: A 50-year Retrospective”. Journal of Traffic and Transportation Engineering (English Edition),Vol. 10, Issue 5, pp. 866-877, but this would be unnecessary self-referencing.

In any case it is a blanket claim that does not take into account that throughout the world there are repeated cases in cities of trip-de-generation in the face of removal of road capacity…a lot of traffic simply disappears and the claimed alternative routes simply are not needed. The tearing down of the massive freeway in Seoul to create a river boulevard, the creation of Swanston Street public transport mall in Melbourne where none of the feared traffic chaos on surrounding streets occurred, demolition of the Embarcadero in San Francisco, pedestrianisation of German city centres where studies were done showing 70% of existing traffic vaporised and it did not show up on any surrounding streets. I think that the paper needs to acknowledge that is far from a blanket rule that is claimed.

RESPONSE: We draw on our experience of traffic engineering practice, and evaluations of LATM schemes in Australia, whereby the measures introduced to deter through traffic in residential areas have largely been successful, but we have found no evidence that vehicular traffic has been suppressed (especially during peak periods with predominantly journey-to-work travel that previously had tried faster routes through residential neighbourhoods).

Line 531: In my review of the original paper, I pointed out the problematic nature of the 700 AV cars/1000 persons, especially given Australian cities today do not even reach this level of car availability through private ownership. Since the paper is claiming sustainability advantages it is a little hard to understand why such an extraordinary level of car availability would be needed. RESPONSE: The figure is based on the highest rate obtained from data in Queensland, As part of another research project supervised by the authors, this extreme value was chosen for a traffic impact analysis of a hypothetical mobility hub for the worst-case vehicular traffic generation on surrounding roads.

BUT MORE THAN THIS, this level of AV car availability is proposed for the authors’ MOBILITY HUB, which is their premier, quintessential example of reduced car use, sustainable mobility, reduced parking, etc etc. So, I fail to see if mobility hubs are going to enhance public transport use, reduce car use, reduce parking and make NMM more attractive, why on earth such high levels of cars (more than currently is the case in Australian cities with conventional cars, or indeed most cities), would be needed. To me it simply does not make sense. Furthermore, I do not understand why the authors, having responded to the original comment, by complete removal of this idea, it suddenly finds it way back in. Are the two authors not communicating correctly with each other, perhaps?  RESPONSE: See above, but we agree it is too premature to introduce traffic impact analysis so the number is deleted.

4. Lines 720-728 repeat exactly from earlier in the current paper. The authors need to decide where this text belongs and only use it once.RESPONSE: Thank you for pointing this out. We have deleted duplicate paragraph at line 539ff.

Finally, in the cover letter, the authors provide the following block of text, which is their response to the last substantive comment of mine in their cover letter. The text is meant to be inserted in the paper. However, the text is nowhere to be found.

If the land-use planning concepts discussed in this paper come to fruition we should speculate on a plausible modal split for fully autonomous private vehicles and taxis, public transport, and other non-motorised forms of transport. Supported by apps with real-time information on alternative modes, their costs and routes, there is likely be be more multi-modal trips with more transfers. Autonomous taxis are already in operation so their market share is most likely to expand with more people realising their availability and reliability makes the private ownership of motor vehicles unnecessary. Mobility hubs with shared private fully autonomous vehicles properly financed and managed by a body corporate may be an attractive proposition for some sections of the community, especially with an ageing population. In the case of Australia with its high car ownership and use, it is hard to imagine that shared AVs and AV taxis would make up 30 per cent of the urban travel market with walking, cycling, e-bikes and scooters making up an aspirational 20 percent of the market.

Additionally, in this text they say: “…it is hard to imagine that shared AVs and AV taxis would make up 30 per cent of the urban travel market with walking, cycling, e-bikes and scooters making up an aspirational 20 percent of the market”.>>RESPONSE: We cannot explain why this was not included in the revision but it now reads: If the land-use planning concepts discussed in this paper come to fruition then modal choice may change. It is not too hard to imagine that shared AVs and AV taxis would make up 30 per cent of the urban travel market with walking, cycling. e-bikes and scooter making up an aspirational 20 per cent of that market. Supported by apps that provide real time information of times, costs and the best routes to take in a network of multi-modal transport, AVs can boost the usage of public transport, especially by providing services for the “first” and “last” mile of a journey..

 

Do they mean it is NOT hard to imagine? In any case this text needs to be inserted in the paper. Comment: Correct – It should read: “…it is not hard..

Editorial comments

Line 49 “ a starting point” - corrected

Line 173: and the creation - corrected

Line 185 is not ais - corrected

Line 373 providing not proving – mistake not found

Line 376 corridors are movement spaces - corrected

Line 383 is involved not are involved – mistake not found

Line 393 I have pointed out on two occasions that the term “the disabled” will get the authors (and the journal) into hot water. It is now “differently-abled” if I am up to date. As early as 1993 or before, "the disabled" was black-banned, and it became “people with disabilities”…now even this term is forbidden too. This problem is also in Table 1…last line on p.14. corrected

Line 561 who should MANAGE the mobility hub…new line 564-  own

Line 561 We BELIEVE that not belief.- corrected

Line 579 I strongly suggest rec-considering the acronym BOMB in the current global political environment. It is a bit insensitive. Changed to “Bureau for Mobility”

Line 624/5 – problem with sub-heading - corrected

Line 652 that a fleet. – sentence deleted as redundant.

Line 859 an exemplar not a exemplar. - corrected

If these final fix ups are completed properly, then I recommend publication.

 

Comments on the Quality of English Language

Still editorial minor issues as listed in my comments. RESPONSE – Another proof read was undertaken by three people

Reviewer 5 Report

Comments and Suggestions for Authors

I  am not satisfied with authors responses and revison. In that way, I do recommend to reject it. 

Comments on the Quality of English Language

English should be improved.

Author Response

Reviewer 5:

 

Merely says: “I  am not satisfied with authors responses and revision.”

The authors cannot respond unless there are specific comments.

Round 4

Reviewer 1 Report

Comments and Suggestions for Authors

I have selected minor revision, but this is indeed just a few minor English fix ups, possible improvement of figures and one final comment on modal split. I do not need to see the paper again and I have recommended publication.

This has been a long road for you and for me, since I have never put so much time into reviewing any paper, but I believe the time and effort was worth it, as it is now, I believe a much better paper, which can stimulate debate.

It is not up to me to decide about the quality of the figures. As far as information goes, they are very detailed and interesting, but sometimes cluttered with text overlapping and I find in some places too small and barely readable. So perhaps the journal will demand some revisions there.

In the projected modal split paragraph that you inserted which was left out of the last version, you say 30% AV, 20% NMM. That is 50% of all daily trips. Are we to assume the remaining 50% is PT? Or, is the remaining 50% mainly private normal cars...so what's the split so that it adds to 100%...makes sense to me to just clarify this because your claim is a radical improvement in transport sustainability, but this depends very much on what modes are used for the 50% of trips that you do not comment on!!

In terms of the "mistakes not found" that you note, you will find that the mistakes indeed are there in the lines quoted.

Line 373 is meant to be providing not proving. What you are trying to say as I read it, is there is a caveat on the statement as in "provided that, blah, blah...".

Line 383 when you say "the community" the word "the" is the definite object and "community" is singular not plural, so it has to be "the community is..." In speech it is of course common to hear, for example, "the community are up in arms". But it is strictly "the community is up in arms."

Additionally, there is:

In Line 98 it should be "a low-density suburb", NOT "a low-density suburbS"

Line 446-454...the spacing becomes single space.

Comments on the Quality of English Language

Still minor fix-ups required. I think the modal split request should be fixed.

If you would do me the courtesy of sending me the final paper after this round, I would appreciate it, but I have recommended publication now. I would like to know about how they respond to the modal split question.

Author Response

 

Suggestions for Authors and Comments to Editor

 

1. Comments to the Editor

There must be problems in formatting manuscripts across different word processing system. Our third submission contained all text in Palatino Linotype font point 10. This 4^th version fore correction (with tracked changes) arrives with mixed fonts. Also, there is a missing section of line numbering from 354 to 387. This makes it difficult to pick up the reviewer’s comments.

 

 

2. RESPONSE TO REVIWER 1 (in red)

I have selected minor revision, but this is indeed just a few minor English fix ups, possible improvement of figures and one final comment on modal split. I do not need to see the paper again and I have recommended publication.

This has been a long road for you and for me, since I have never put so much time into reviewing any paper, but I believe the time and effort was worth it, as it is now, I believe a much better paper, which can stimulate debate.>>>>The authors appreciate the reviewer’s diligence in the details of four reviews that have finally resulted in a better manuscript. It demonstrates perfectly how the academic publishing model is nonsense: here a reviewer (on a high salary) spends hours of unpaid time in the review process for a journal that asks a potential author for an article processing charge to publish his' or her’s research that is expected as part of academic duties.

It is not up to me to decide about the quality of the figures. As far as information goes, they are very detailed and interesting, but sometimes cluttered with text overlapping and I find in some places too small and barely readable. >>The size of the figures as presented in this version were arranged to avoid unnecessary gaps in the manuscript. The Journal Editor is responsible for the page designs and should adjust figure sizes to be made readable.

So perhaps the journal will demand some revisions there.

In the projected modal split paragraph that you inserted which was left out of the last version, you say 30% AV, 20% NMM. That is 50% of all daily trips. Are we to assume the remaining 50% is PT? Or, is the remaining 50% mainly private normal cars...so what's the split so that it adds to 100%...makes sense to me to just clarify this because your claim is a radical improvement in transport sustainability, but this depends very much on what modes are used for the 50% of trips that you do not comment on!!

It is very hard to speculate about the future modal split in a city with autonomous vehicles. Much will depend on the production and marketing strategies adopted by the major international automotive manufacturers once the penetration into the market of electric and hydrogen cell passenger vehicles has been achieved. Robotaxis are already operational in some cities so their mode share is likely to expand. If the land-use planning concepts discussed in this paper come to fruition, and real-time information on door-to-door travel on a multi-modal network is made available to consumers then modal choice may change. It is not too hard to imagine that AV taxis would make up 20 per cent of the urban travel market with walking, cycling. e-bikes and scooter making up an aspirational 20 per cent of that market. AVs can boost the usage of public transport, especially by providing services for the “first” and the “last” mile of a journey, say to 30 per cent across the city. If a target were set to limit (for all sorts of essential reasons) 30 per cent usage of private personal transport then the urban transport sector would move in the direction of greater sustainability. There is a further possibility: autonomous vehicles (whether taxis, privately owned or shared) all have controls built into them which allows the mobility system master controller to direct traffic depending on congestion and available infrastructure.  In this case, the distinction between public and private transport in any mode split analysis loses its current meaning.

 

 

In terms of the "mistakes not found" that you note, you will find that the mistakes indeed are there in the lines quoted.

Line 373 is meant to be providing not proving. What you are trying to say as I read it, is there is a caveat on the statement as in "provided that, blah, blah...".>>> line 348 reads; “. Importantly, when considering fully autonomous vehicles, planning can provide a basis

Line 383 when you say "the community" the word "the" is the definite object and "community" is singular not plural, so it has to be "the community is..." In speech it is of course common to hear, for example, "the community are up in arms". But it is strictly "the community is up in arms.">>>OK

Additionally, there is:

In Line 98 it should be "a low-density suburb", NOT "a low-density suburbS" - corrected

Line 446-454...the spacing becomes single space. >>Yes this is to do with formatting by the system (see above comment to Editor)

 

Comments on the Quality of English Language

Still minor fix-ups required. >>>All points corrected

I think the modal split request should be fixed.>>Done