Analysis of the Effect of Providing Pedestrian Crossing Information at the Blind Spots of Intersections on Vehicle Traffic
Round 1
Reviewer 1 Report
Page 4 - Line 139: Figures 2a and 2b include letters that are not written in English. These figures need to be replaced with another figures that have all letters and symbols written in English language. Regarding Figure 3, I understand that these photos were captured in the field, so the language can be kept the same but I would encourage the authors to add a translation for the master display and pedestrian display messages in (3b) and (3c).
I would encourage the authors to define the meaning of "blind spots at intersection" in the write-up with references from published studies. Also please identify the location of the intersection blind spot on a figure 3a.
Page 6 - Table 1: I am not sure what is the benefit of presenting the vehicle counts before and after the system installation. The information provided in Table 1 is not enough. I would encourage the authors to add a paragraph and/or a table that shows the data variables that were collected as part of the field survey. For example, point speeds and speed limit compliance rate.
Honestly I don't agree with the method that was used for collecting the speed measurements. The location of the radar equipment on the roadside is very obvious to the drivers and this by itself will influence their driving speeds. Normally when we conduct spot speed studies, we try to hide the speed radars as much as we can. How can the author validate the speed measurements? This speed validation is really important to make the results sound since this was the only measure of the system impacts on drivers. I will leave this to the authors to decide how they want to validate the speed results.
Line 159, the authors wrote (178 vehicles before and after installation and 166 vehicles after installation were collected. Please fix the errors in the sentence. I found many similar writing errors in the paper. Extensive editing of English and style is required. The full paper needs to be revised, proofread and edited by an English editor.
Line 166: the authors mentioned "there is a limit to detecting only right-turning vehicles" can you please explain more in the write-up what is this limit. And what do you mean by round-trip two-lane road?
Author Response
Please see the attachment.
Author Response File: 
Author Response.docx
Reviewer 2 Report
Dear Authors,
It was a great pleasure to review your manuscript addressing the question of whether the pedestrian crossing information notification system has a threshold effect on traffic safety.
As far as I understood from the manuscript, your research aims to provide an interesting approach to the analysis of a pedestrian crossing information notification system developed in Korea that can help traffic safety. However, both in the title and abstract of the manuscript, it is unclear whether the research has studied a particular case in Korea and where exactly and how long the research has been carried out.
As explained below, some aspects of your research approach are unclear and therefore should be deeply improved for a better understanding of the whole manuscript.
I hope your efforts in revising the manuscript according to the comments below can make the paper more attractive, thus satisfying the high demands of the Sustainability (ISSN 2071-1050) readers.
#Abstract:
Please be aware that all words reflected in keywords must be previously quoted from the abstract in order of appearance. Specifically, “Intersection blind spot” and “pedestrian safety”, “pedestrian crossing information”, “pedestrian crossing information provision system” should have explicitly been written in the abstract since they have been used as keywords. However, they have not written explicitly in the abstract. Please correct this as soon as possible.
Furthermore, the abstract should be explicit and contain all necessary details on the specifications of your research (where, when, and how long).
#Introduction:
This part is a bit short and does not help readers to understand the whole framework of the research approach that should meet the scope of the journal. I urge you to expand it for a better explanation of the scope of your study, particularly those aspects of your approach that have relevance to the pedestrian crossing information in terms of sustainability.
There is also a lack of explanation on where exactly you have focused the study case. In fact, when you say (see lines 71-72), “Therefore, this study analyzed the effect of a pedestrian-crossing information notification system provided in the blind spot of the intersection installed in Jeollabuk-do”, I just was wondering whether the study has been conducted on all road intersections (!?) of such a province or only on one of them (!?). Please be aware of international readers who have no idea about Korean geography.
The acronym “VMS” should be defined for the first time since this is the acronym for the full name, as expected, “Visual Monitoring System”. The same applies to all acronyms in your paper. As obvious as it sounds (for instance, OCDE), all acronyms must be defined when they are used for the first time.
When you say (see lines 66-67), “However, in most similar studies, the changes in vehicle travel behavior were not effectively investigated (…)”, this seems a bold statement and should be done very carefully. Thus, I encourage you to explain more widely those related effects, and thus why this is in line with the scope of your research. Your assertion should also be supported by several earlier works since you are talking about “in most similar studies …”
#Literature Review:
For a quick understanding of this section, I strongly suggest you summarize the main ideas from each contribution of earlier works through a table.
#Pedestrian crossing information notification system
Figure 1 and further. The credit photo is missing in each photo/figure. Who is the photographer, drawer, designer, etc.? Please be aware that all figures, pictures, or something like that, which are shown in academic papers, must be credited with the name of the authors/sources. Otherwise, without permission, please delete them immediately. Moreover, some figures do have not enough quality to be shown in an academic paper (e.g. Figure 2). Please try to use them with better quality.
Table 1 and further. There is a lack of table notes. No table should be shown in a scientific paper without a trusted database properly cited (preferably based on primary sources). This is a must for any researcher drafting a manuscript.
Lines 159-160: When you say, “In the 150 min survey conducted before and after system installation, data of a total of 178 vehicles before and after installation and 166 vehicles after installation were collected”, I expect to know where the survey has been hosted and how respondents have acceded to answer it. Please give further information about the survey, such as the URL, number of questions, quality control questions, etc. Furthermore, a technical survey form is missing.
Regarding “Figure 5. Distribution of point speed by vehicle rotation”, you should have indicated the source thereof. That is, you must write “Source: Own elaboration / Own compilation based on [referred to the primary source, if applicable]”, or something like that. The same applies to all other figures and tables shown in the manuscript.
Lines 235-236: When you say, “(…)the difference in point speed when approaching the intersection according to the presence of pedestrians was not statistically significant..”, I wonder how insignificant in statistical terms it was. It is absolutely imperative that these kinds of sentences can be expressed with certainties based on your findings, or even from previous works, through the scientific method. Please avoid using unvarnished sentences throughout the manuscript.
Since this subsection would need to strongly improve for a better understanding, I strongly suggest expanding it by creating a new section called “Discussion”.
#Conclusion
This section is a bit short. This part of your manuscript seems so vague in terms of conclusions. Moreover, I strongly suggest examining in greater depth the conclusions drawn from the analysis of the results under your research approach.
The summary of results, either the accurate information regarding traffic safety and traffic flow and vehicle speed as a major indicator on the matter, is very valuable for the explanation of the findings from your research. Thus, in line 265, when you say, “From the results of this study, we have two points of discussion”, for the sake of better presentation, they should be shown in a table or bulleted list, besides the valuable tables shown in this subpart. In fact, tables 4, 5, and 6 are particularly interesting for understanding the effect of the results obtained.
Lines 262-263: When you say, “there is no doubt that the provision of pedestrian information in advance in the blind spot is a factor that can attract the driver's attention”, this seems a bold statement and should be done very carefully. Thus, I encourage you to explain more widely why this is in line with the findings of your research. Moreover, your assertion should be supported explicitly by previous works, where possible.
I also cannot see any relationship between the findings of your study and the aims thereof in terms of sustainable road traffic. Not once is the term “sustainability” mentioned in the manuscript. Therefore, I encourage you to review the content of this section that favors an approach toward sustainability to meet the scope of the Sustainability journal more closely.
Additionally, I suggest that a separate section should be devoted to explaining your research recommendations for future studies.
Best regards,
the Reviewer.
Author Response
Please see the attachment.
Author Response File: 
Author Response.pdf
Reviewer 3 Report
The study is conducted to analyse the effects of providing pedestrian crossing information in blind spots at intersections on vehicle traffic. In general, the paper is good in writing and format. The research question is clear, but data statistical analysis is not sufficient. There are some points that need improvement as follows:
- Abstract (page 1): the field survey was set at a time interval of 4 weeks for drivers to adapt to the system. How do the authors know that drivers are already adapted or not yet? Are they the same drivers who drive through the intersection every day?
- Figure 2 (lines 139-140), page 04: what is the meaning of the displayed information in English? Does the “Master Display” mention pedestrian is crossing ahead (which affects both straight and right-turning vehicles) or the pedestrian is crossing when the driver makes a right turn (which affects only right-turning vehicles)? With different information given, drivers’ behaviours can be different.
- Line 165-166, page 6: What is the limitation to detecting the right-turning vehicle in this statement “…but there is a limit to detecting only right-turning vehicles on a round-trip two-lane road”? Take note that in Table 2 (page 7), there is separate information on straight-ahead running and right-turning vehicles, in which the latter is around 44&42 vehicles. Indeed, the right-turning vehicles have increased their speeds from 20.86 to 21.55km/h from before to after the installation of the warning system, respectively. How to explain this observation?
- Page 06: this sentence is long that needs to be re-structured “Looking at the difference in the average point speed between the straight ahead-running vehicles and the right-turning vehicles, before installation, the speed of the straight ahead-running vehicles were 22.38 km/h on average and that of the right-turned vehicles was 20.86 km/h, showing a deviation of about 1.52 km/h, while after installation, the deviation was about 0.26 km/h with 21.82 km/h for straight ahead-running vehicles and 21.55 km/h for right-turning vehicles”.
- Figure 5, page 07: given a small T-junction area, there are some vehicles that made a right turn at a speed > 45 km/h before installation. What is the explanation for this anomaly?
- Table 3 (page 08) shows the t-test results: what is the research hypothesis for the testing? In the first column (category), it should be the t-value instead of the t-test?
- Lines 208-209, page 8: The meaning of this sentence is not clear “Considering the changes in the speed limit compliance rate for all vehicles, we found that it increased by ~2.52% to ~93.26% (166 units/178 units) before system installation and by ~95.78% (159 units/166 units) after installation”. How come the changes “to ~93.26%” or “by ~95.78%” which are very significant?
- Summary part (4.3), page 10: the contents are similar to the Conclusion, the two parts can be merged into one.
- What is the application of this study, given very little difference in vehicle speeds before and after installation? The study has found that with/without pedestrians the speed decreased/increased by 0.83/0.54 km/h, respectively, with no significant t-test. Should the warning system be suggested to apply on a larger scale at the network level?
Recall that “In this study, when a pedestrian crosses a crosswalk in a right-turn blind spot, an effect analysis was performed on the system that provides information on pedestrians to vehicles entering the intersection” (in conclusion part, lines 246-248), therefore, the more in-depth analysis should be focused on right-turning vehicles. Whereas, the straight-ahead vehicles are not influenced by the crossing pedestrian at the “Trager crosswalk” (see Figure 3).
Comments for author File: Comments.pdf
Author Response
Please see the attachment.
Author Response File: Author Response.pdf
Round 2
Reviewer 1 Report
The authors have addressed my comments. Thanks!
Reviewer 2 Report
Dear Authors,
Thank you for sharing with me the revised manuscript which has deeply been improved following my comments from the prior review.
Explanatory paragraphs have been added to the paper, as well as several changes and additions, thus making it possible for publication in Sustainability (ISSN: 2071-1050).
I particularly appreciate you taking the time to highlight the implications of how your study analyzes the effect of providing pedestrian crossing data in blind spots at intersections on vehicle traffic from related information systems can constitute a potential basis for future analysis and methodological formalization of a topic that can also be certainly interesting for potential research in achieving sustainable traffic safety.
Due to all the above, I truly think the manuscript can now be accepted for publication.
Sincerely,
The Reviewer
Reviewer 3 Report
I have no more comment.
