Technological Evolution in the Swiss Bus Fleet from 1940 to 2022: An Inventory and Database for Research Applications
Round 1
Reviewer 1 Report
Comments and Suggestions for AuthorsOverall, this report is a valuable contribution to the understanding of the technological evolution of the Swiss bus fleet. It provides a solid foundation for further research and policy development to enhance public transportation efficiency and sustainability. The inventory created serves as a critical resource for evaluating the impact of technological advancements on the environment, passenger comfort, and driver working conditions. With some additional focus on country-specific factors, passenger comfort, and future projections, the report could be even more impactful. Attached you can find a file with some minor issues that I have detected and require your attention.
Comments for author File: 
Comments.pdf
Author Response
Thank you very much for taking the time to review this manuscript in detail. We took out the highlighted words, corrected the wording and grammar. Please find the corresponding revisions in track changes in the re-submitted files.
Reviewer 2 Report
Comments and Suggestions for AuthorsFigure 4 is blurry. It needs to be changed with a higher resolution image.
Writing mistakes must be corrected. Carbon dioxide CO
Please see more in the attachment.
Comments for author File: Comments.pdf
Author Response
Thank you very much for taking the time to review this manuscript in detail. We took out the highlighted words, corrected the wording and grammar. Please find the corresponding revisions in track changes in the re-submitted files.
Comment 1: Figure 4 is blurry. It needs to be changed with a higher resolution image.
Response 1: Thank you for pointing this out. We have changed the Figure 4 with a higher resolution image.
Comment 2: Writing mistakes must be corrected.
Response 2: Thank you for pointing this out. We have corrected all the mistakes that we saw by using Grammarly to correct our English. You will find all the corrections in track change in the re-submitted files.
Comment 3: For improvement of the paper, the authors should develop an accessible interface for transport specialists. It can be creating an application-type interface for any type of device (phone, laptop) that shows the users the bus fleet development through the years, from 1940 to 2022 and the differences between the used means of transport.
Response 3: We thank the Reviewer for this suggestion. We agree that such an interface is of interest and would be useful for transport specialists. However, for the moment being, we do not have resources for developing such an application. If anyone is interested in developing such an interface, we would be delighted to help and provide all information.
Comment 4: The conclusions refer to the database created as a result of the research. Perhaps more information should be added on the replacement of combustion engine vehicles with electric and hybrid vehicles in recent years. To highlight the sustainability of the transport system.
Response 4: We agree with these remarks. We have added a sentence in the conclusion (p.7, lines 201-203) which reads as follows: “Moreover, the database also captures the hybridization and electrification of the Swiss bus fleet, reflecting efforts to enhance the sustainability of the public transport system and reduce emissions.”
Comment 5: The references are appropriate. But the links that are inserted into the text should only be written at References.
Response 5: Thank you for this comment. We have removed the links in the text and added them as quotes. The changes can be seen on lines 115, 121 and 192 in the resubmitted manuscript.
Comment 6: At Table 2 and Table 3, “N” is the number of vehicles. It should be replaced by “Nr.” or “Number”. To be clearer.
Response 6: Thank you for this suggestion. We have changed Table 2 and Table 3, the “N” was replaced by “Number”.
Reviewer 3 Report
Comments and Suggestions for AuthorsGlad to review the manuscript (sustainability-3203391). This paper mainly studied the technological evolution and database construction of the bus fleet in Switzerland from 1940 to 2022, providing a detailed analysis and description of the technical characteristics and development of the bus fleet in Switzerland. The potential impact of the evolution of bus technology on drivers' occupational exposure and environmental impact were estimated. This paper is poor logic with a lack of innovation. Sorry for the rejection recommendation. In detail, some concerns for authors’ considerations:
(1) In Sec 2.2, Data analysis, what are the reasons to use these criteria when determining a latent category model? Are there some connections between these standards?
(2) In Sec 3.2, Figures, Tables, and Schemes, There was an 'Error! Reference source not found? The overall description is not detailed enough and is a bit confusing, and this reorganized language needs to be written clearly.
(3) In Sec 4.1, Result interpretation, it is not stated what solutions/methods were used, but only the results are presented, and the results obtained do not prove their legitimacy.
(4) The diagram of the entire article needs to be redrawn to a level that is clear and easy to understand and to be produced to a consistent standard.
(5) There are certain limitations in using LCA to define bus classification, correct classification cannot be guaranteed, and misclassification may occur, especially since some bus models built in the 70s of the 20th century may be incorrectly classified, and this limitation needs to be overcome.
(6) The summary is too concise and lacks further research on future programming.
(7) Last, what is the motivation of this study? After all, it is not a report. Is the latent class analysis method particularly suitable for this focused problem?
Comments on the Quality of English LanguageIt is better to improve the language level.
Author Response
Thank you very much for taking the time to review this manuscript in detail. We took out the highlighted words, corrected the wording and grammar. Please find the corresponding revisions in track changes in the re-submitted files.
Comment 1: In Sec 2.2, Data analysis, what are the reasons to use these criteria when determining a latent category model? Are there some connections between these standards?
Response 1: We thank Reviewer 3 for these questions. Concerning the choice of variables included in the latent class models, they were chosen based on multiple strategies to find the underlying structure of the data, which will be used in further analysis. The first one was to include variables following the advises of our experts. The second was to choose the variables based on bus characteristics that could influence two of the most measured bus drivers’ occupational exposure: vibration and noise. This strategy is based on our need for further epidemiological studies. Concerning the choice of criteria to select the final latent class model, we created the criteria based on explanation of bus experts. We wanted to select a latent class model that was exploitable in further analysis and that followed objective criteria to compare the latent class models. Criteria were also developed following advice from bus experts such as the similitude of the bus of the same model family, which were a derivation of a base model with options for example, the floor height. Each criterion is independent.
Comment 2: In Sec 3.2, Figures, Tables, and Schemes, there was an 'Error! Reference source not found? The overall description is not detailed enough and is a bit confusing, and this reorganized language needs to be written clearly.
Response 2: Thank you for this comment. We apologies for this error. We have corrected this section. The changes can be seen at page 5 of the re-submitted manuscript. The missing reference was replaced by “Table 1”, the correct reference.
Comment 3: In Sec 4.1, Result interpretation, it is not stated what solutions/methods were used, but only the results are presented, and the results obtained do not prove their legitimacy.
Response 3: Thank you for your insightful comment. Section 4.1 focuses on discussing the results presented in Section 3, specifically the latent class analysis, which can be challenging to interpret without detailed explanation. The methodology for the results discussed in Section 4.1 is now outlined in Section 2.2 on Data Analysis (pages 3-4). To enhance clarity and ensure it is evident that we are discussing the outcomes of the latent class analysis, we have updated the title of Section 4.1 to "Latent Class Analysis as a Tool for Understanding Bus Generations and Technological Evolution." (p.14, line 47)
Comment 4: The diagram of the entire article needs to be redrawn to a level that is clear and easy to understand and to be produced to a consistent standard.
Response 4: Thank you for your comments. The Figure 4 was replaced by a higher resolution image. All the other diagrams (Figure 1, Figure 2 and Figure 3) have been approved by public transport companies, the Swiss Federal Office of Transport and the Union des Transports Publics (UTP). They find them clear and easy to understand. Therefore, we cannot change them anymore.
Comment 5: There are certain limitations in using LCA to define bus classification, correct classification cannot be guaranteed, and misclassification may occur, especially since some bus models built in the 70s of the 20th century may be incorrectly classified, and this limitation needs to be overcome.
Response 5: We thank the Reviewer 3 for this comment. While it is true that some degree of misclassification is inevitable in latent class analysis and cannot be fully eliminated through statistical methods, we took several steps to minimize this risk. To ensure accuracy, we carefully reviewed all bus models within each latent class to verify their proper classification based on the class composition. In cases of uncertainty, we consulted with experts, including bus drivers and members of the UTP, to confirm the correct classification for each bus model. These measures helped reduce the likelihood of misclassification. The following sentence was added in the manuscript (p. 16, lines 147-149) highlight that several steps were taken to lower the risk of misclassification: “We reviewed all bus models in each latent class to ensure proper classification and consulted experts, such as bus drivers and UTP members, when needed to reduce the likelihood of misclassification.”
Comment 6: The summary is too concise and lacks further research on future programming.
Response 6: We thank Reviewer 3 for the comment. However, due to number of word limitation, it is not possible to add more information into the abstract, in fact we have 200 words out of 200 words allowed.
Comment 7: Last, what is the motivation of this study? After all, it is not a report. Is the latent class analysis method particularly suitable for this focused problem?
Response 7: Thank you for these questions. The primary motivation for this study was to create an inventory of the Swiss bus fleet dating back to the 1940s, which could be utilized by other researchers, for instance in risk assessment and epidemiology. Additionally, we aimed to uncover the underlying structure of the bus model inventory, which is why we chose latent class analysis (LCA). LCA offers several advantages over other classification methods, like clustering. The two key reasons we selected LCA are its probabilistic classification, avoiding rigid clusters, and its ability to reveal hidden subgroups based on data patterns. Moreover, the LCA results align with the historical evolution of the Swiss bus fleet (Figure 2 in the manuscript), further supporting the appropriateness of this method for our study.
Round 2
Reviewer 3 Report
Comments and Suggestions for AuthorsMy assessment is that the quality of this paper (sustainability-3203391) is well below the standards of sustainability. The paper rarely contains the necessary innovations on the study concept. In terms of ‘Technological evolution’, I did not find out what technology was improved or tailored for Swiss bus fleet. If only for application, it is far away from a good paper. It's more like a report rather than a research.
My serious concern is what contribution exists in this paper ?
Sorry again for not support this manuscript anymore.
Comments on the Quality of English LanguageThe language is clear.
Author Response
Dear Reviewer 3,
We would like to thank you for your attention to our work and would like to clarify a few points about the scientific nature of our approach. Indeed, data inventories and retrospective reviews of changes are essential steps in scientific research. They help consolidate knowledge, identify trends, and provide a global perspective on the subject in question. Numerous research was preceded by the publication of a data inventory, for example, Ben Rayana et al. article on the construction of a PM10 job exposure matrix (JEM) [1-2], and Peters et al. article on a quantitative JEM for lung carcinogens [3-4].
Our approach is to bring these elements together in a rigorous and methodical way, to contribute to the advancement of knowledge in our field. The publication of this work in the form of an article is fully in line with the editorial line of the journal.
That said, we naturally respect the editorial process. The decision to accept or reject a manuscript rest exclusively with the Editor. Please do not hesitate to contact us should you have any further questions or require any clarification.
Yours sincerely
The authors
[1] Ben Rayana, T.; Wild, P.; Debatisse, A.; Jouannique, V.; Sakthithasan, K.; Suarez, G.; Guseva Canu, I. Job Exposure Matrix, a Solution for Retrospective Assessment of Particle Exposure in a Subway Network and Their Long-Term Effects. Toxics 2023, 11, 836. https://doi.org/10.3390/toxics11100836
[2] Ben Rayana, T.; Debatisse, A.; Jouannique, V.; Sakthithasan, K.; Besançon, S.; Molle, R.; Wild, P.; Guinhouya, B.C.; Guseva Canu, I. Sixteen-Year Monitoring of Particulate Matter Exposure in the Parisian Subway: Data Inventory and Compilation in a Database. Atmosphere 2022, 13, 1061. https://doi.org/10.3390/atmos13071061
[3] Susan Peters, Roel Vermeulen, Lützen Portengen, Ann Olsson, Benjamin Kendzia, Raymond Vincent, Barbara Savary, Jérôme Lavoué, Domenico Cavallo, Andrea Cattaneo, Dario Mirabelli, Nils Plato, Joelle Fevotte, Beate Pesch, Thomas Brüning, Kurt Straif, Hans Kromhout, SYN-JEM: A Quantitative Job-Exposure Matrix for Five Lung Carcinogens, The Annals of Occupational Hygiene, Volume 60, Issue 7, August 2016, Pages 795–811, https://doi.org/10.1093/annhyg/mew034
[4] Peters S, Vermeulen R, Olsson A, Van Gelder R, Kendzia B, Vincent R, Savary B, Williams N, Woldbæk T, Lavoué J, Cavallo D, Cattaneo A, Mirabelli D, Plato N, Dahmann D, Fevotte J, Pesch B, Brüning T, Straif K, Kromhout H. Development of an exposure measurement database on five lung carcinogens (ExpoSYN) for quantitative retrospective occupational exposure assessment. Ann Occup Hyg. 2012 Jan;56(1):70-9. doi: 10.1093/annhyg/mer081. Epub 2011 Oct 11. PMID: 21989165.
Round 3
Reviewer 3 Report
Comments and Suggestions for AuthorsThanks for the authors’ revision (ID: sustainability-3203391) in the 3rd round. As told, the paper is still well below the publication standard of Sustainability Journal. There is no necessary modeling and solution method for handling the integrated problem, i.e., 'optimizing public transportation, improving service efficiency, meeting future demands, and incorporating environmentally friendly technologies' mentioned in the Abstract. What's the application area of the estimation? The word is too simple. Although the paper has improved much, I still have not found enough innovations or contributions to facilitate PT development.
Comments on the Quality of English LanguageThe language level is clear.
