Observed Risk and User Perception of Road Infrastructure Safety Assessment for Cycling Mobility

Round 1

Reviewer 1 Report

1. CSE is the abbreviation for critical safety event rather than SCE
2. A more detailed description about internal information including kinematical and dynamical quantities would be helpful
3. Rank 5 indicates the safest and rank 1 most unsafe (line 290-291) as in Table 2
4. Although the paper refers to articles from a number of countries (Poland, Australia, USA, Brazil, Norway, Belgium, Italy) the conclusions are based primarily on the experiments performed in Catania, therefore the examination should be verified with the use of experiments made at other places, including the ones of different level of development
5. Psychological issues (for instance gender aspects, human attitude toward the experiments) can play some role as regards the perceived risk, thus the resulting conclusions cannot be so strict.
6. The correlation issues between both types of risk should be better explained

Author Response

Thank you very much for your positive assessment and for your constructive remarks, which have led us to further improve our work. We have taken your comments into account and addressed them as follows:

1. CSE is the abbreviation for critical safety event rather than SCE

The authors thank the reviewer for the suggestion, but both acronyms may reflect the same concept. We opted to use  Safety Critical Event (SCE) since it is more often used in the literature.

2. A more detailed description about internal information including kinematical and dynamical quantities would be helpful

More details are provided in paragraph 2.2.2.

3. Rank 5 indicates the safest and rank 1 most unsafe (line 290-291) as in Table 2

We apologize for the oversight; we have made the correction.

4. Although the paper refers to articles from a number of countries (Poland, Australia, USA, Brazil, Norway, Belgium, Italy) the conclusions are based primarily on the experiments performed in Catania, therefore the examination should be verified with the use of experiments made at other places, including the ones of different level of development

We appreciate the comment and in our revised manuscript we used international references to introduce the topic. Results of the study can be referred to the risk perception’ of user’ in Catania. A comment was added in the conclusion.

5. Psychological issues (for instance gender aspects, human attitude toward the experiments) can play some role as regards the perceived risk, thus the resulting conclusions cannot be so strict.

We have added a comment in the conclusion.

6. The correlation issues between both types of risk should be better explained

We have added a comment in the revised manuscript.

Reviewer 2 Report

The manuscript focuses on a topic of fundamental importance for the safety of cyclists.
The text has several grammatical errors. It is necessary to insert all acronyms in an expanded form when first entering the text.
For a better understanding of the research steps, a flow chart should be included in the introduction. 
It is necessary to highlight the novelty of the research and to better explain the choice of the case study and the possible replicability of the methodology adopted.
With regard to the sample of cyclists, it is useful to include more information about the age distribution (in the text it is written from 27 to 65 years), gender and previous experience in using a bicycle (standard or pedal-assisted) in the examined context.
In the concluding part, it is necessary to insert the limitations of the research. 
It is necessary to insert figure 3 in high resolution.
It is useful to describe whether the sample of cyclists is included as a proportion of the sample that participated in the questionnaire. It is also necessary to justify the smallness of the sample compared to the population of Catania.
Figures 7 and 8 should be inserted in high resolution.
The monograph needs an extension of the related bibliography; therefore it is suggested that references be included both to the evolution of bicycle mobility in Catania and in Sicily/Italy but also references to pre-post Covid-19 mobility.

Finally, it is suggested to specify the choice of the places examined, highlighting their specificities.

 

Author Response

Thank you very much for your positive assessment and for your constructive remarks, which have led us to further improve our work. We have taken your comments into account and addressed them as follows:

The manuscript focuses on a topic of fundamental importance for the safety of cyclists.

1. The text has several grammatical errors. It is necessary to insert all acronyms in an expanded form when first entering the text.

The revised manuscript has been thoroughly edited.

2. For a better understanding of the research steps, a flow chart should be included in the introduction.

A flow chart is included in the introduction.

3. It is necessary to highlight the novelty of the research and to better explain the choice of the case study and the possible replicability of the methodology adopted.

Additional discussion  has been added in the conclusion.

4. With regard to the sample of cyclists, it is useful to include more information about the age distribution (in the text it is written from 27 to 65 years), gender and previous experience in using a bicycle (standard or pedal-assisted) in the examined context.

Additional information has been added in the revised manuscript.

5. In the concluding part, it is necessary to insert the limitations of the research.

Discussion on the research limitations has been added.

6. It is necessary to insert figure 3 in high resolution.

We have improved the resolution of the figure which, however, is affected by the movement of the vehicles.

7. It is useful to describe whether the sample of cyclists is included as a proportion of the sample that participated in the questionnaire. It is also necessary to justify the smallness of the sample compared to the population of Catania.

We have added discussion on this topic. The test riders have been selected as not participating in the survey to maintain independent the two procedures. The sample size of participants in the survey was statistically tested and the estimated precision of 10% can be considered appropriate. It is not possible to compare the sample with the Catania population of cyclist due to the lack of available data for that. Comments and formula were added in the paper.

8. Figures 7 and 8 should be inserted in high resolution.

We have improved the resolution of figures.

9. The monograph needs an extension of the related bibliography; therefore it is suggested that references be included both to the evolution of bicycle mobility in Catania and in Sicily/Italy but also references to pre-post Covid-19 mobility.

Additional references and comments have been added in the introduction to address the reviewer’s comment.

10. Finally, it is suggested to specify the choice of the places examined, highlighting their specificities.

Additional discussion has been added to address the reviewer’s comment.

 

Reviewer 3 Report

Vehicle”

In this study, the author designed a study to investigate the effect of two different methodological approaches for cycling safety assessment of observed and perceived risk. The objective risk is calculated using the GNSS system, and perceived risk is computed by using an online survey. The paper is well written and arranged scientifically. Moreover, the outcomes of this research are significant and will be useful to address bicycle safety. Before the final acceptance, kindly consider the following points in the revised manuscript.

1. Table 1 consists of ANOVA findings for the absolute Intraclass Correlation Coefficient, while Table 3 consists of the one-way ANOVA result for the five roadway components. Usually, we adopt ANOVA when we satisfy two main assumptions that data is normally distributed and has homogeneous variances. However, I did not find any statement about these constraints. Please clarify.
2. From Figures 7 and 8, it is seen that there is no linear relation between objective and perceived risk. That’s why depicting a small number, and the model is a spurious model. It is suggested to use the spline regression or any other nonlinear model to provide a better relationship between objective and perceived risk.
3. Please provide the limitations of the study.
4. Based on this study, what do you suggest to the policymakers?

Author Response

Thank you very much for your positive assessment and for your constructive remarks, which have led us to further improve our work. We have taken your comments into account and addressed them as follows:

In this study, the author designed a study to investigate the effect of two different methodological approaches for cycling safety assessment of observed and perceived risk. The objective risk is calculated using the GNSS system, and perceived risk is computed by using an online survey.

The paper is well written and arranged scientifically. Moreover, the outcomes of this research are significant and will be useful to address bicycle safety. Before the final acceptance, kindly consider the following points in the revised manuscript.

1. Table 1 consists of ANOVA findings for the absolute Intraclass Correlation Coefficient, while Table 3 consists of the one-way ANOVA result for the five roadway components. Usually, we adopt ANOVA when we satisfy two main assumptions that data is normally distributed and has homogeneous variances. However, I did not find any statement about these constraints. Please clarify.

We have expanded our discussion to address these comments. Because the questionnaire is in Likert-Scale, a non-parametric statistic is advisable. We used the parametric ANOVA test because results are usually acceptable as well. Anyway, thanks to reviewer comment, in the paper the non-parametric Kruskal-Wallis test is now used to test different in medians among survey results in Table 3 (now Table 2). Results are consistent with the ANOVA test because confirmed the statistically significant difference among the medians at the 95.0% confidence level. ICC is not yet reported, because a_wg, that does not need normality assumption, provides all the necessary information to assess the Delphi process.

2. From Figures 7 and 8, it is seen that there is no linear relation between objective and perceived risk. That’s why R^2 depicting a small number, and the model is a spurious model. It is suggested to use the spline regression or any other nonlinear model to provide a better relationship between objective and perceived risk.

The goal of the analysis was not to build a model but to measure the strength of the correlation between observed and perceived risk. Additional discussion is included in the revised manuscript.

3. Please provide the limitations of the study.

Discussion on the research limitations has been added.

4. Based on this study, what do you suggest to the policymakers?

Additional discussion was added that reflect recommendations to policy makers. Due to the correlation for high/medium severity events with the survey’s response, it will be possible and useful the use of survey to detect areas for critical safety events and identify them in order to improve cycling and support a safer cycling mobility.

 

Reviewer 4 Report

This manuscript addresses bicycle-related use and research. Its theme is adequate and within the scope of publication of this journal, and may be accepted after minor corrections:
a) The title is confusing and does not adequately reflect this type of research;
b) The abstract needs to better show the innovation and main results of this research;
c) The figures must be standardized in terms of size;
d) A flowchart of the experimental procedure must be inserted;
e) Separate the discussion and conclusion section, this joining is not highly recommended.

Author Response

Thank you very much for your positive assessment and for your constructive remarks, which have led us to further improve our work. We have taken your comments into account and addressed them as follows:

This manuscript addresses bicycle-related use and research. Its theme is adequate and within the scope of publication of this journal, and may be accepted after minor corrections:

We thank the reviewer for the comments to improve the paper

1. The title is confusing and does not adequately reflect this type of research;

The title has been modified to better reflect the paper contents.

2. The abstract needs to better show the innovation and main results of this research;

The abstract was revised to address the reviewer’s comment.

3. The figures must be standardized in terms of size;

The figures were revised to address the reviewer’s comment.

4. A flowchart of the experimental procedure must be inserted

A flow chart is included in the introduction.

5. Separate the discussion and conclusion section, this joining is not highly recommended

We have reviewed and separated the discussion and conclusion.

 

Round 2

Reviewer 2 Report

It is necessary to standardise the formatting of the tables and to insert figure 7 in high resolution.
Once these parts of the manuscript have been corrected, it will be eligible for publication. 

Reviewer 3 Report

I would like to congratulate the authors for their excellent work. They have made a very detailed revision and convinced me with good arguments. Therefore, I recommend this article for the possible publication in Infrastructures.