Identifying the Factors Contributing to Freeway Crash Severity Based on Discrete Choice Models
Round 1
Reviewer 1 Report
The authors proposed a very interesting study on freeway's operation safety. Some changes are advised.
- The abstract should be improved, clearly stating the problem, establishing the objectives of the research, defining the methodology, as well as giving details of results and the main conclusions obtained;
- In the Introduction section the authors need to point out how this study is different from other ones. My suggestion is to deeply think about two things: why a new paper is needed in this topic, and what is the specific novel result for their study. The introduction should be written in a way that leads the readers understand these two points;
- Introduction lacks of state-of-art. Please, add at least 10 references to support your points, e.g:
1. 10.33889/IJMEMS.2021.6.1.022;
2. 10.1002/qre.2675
3. Integrated hazards method (IHM): A new safety allocation technique
Falcone, D., Di Bona, G., Duraccio, V., Silvestri, A. ,
- Consider adding a block diagram for better explaining the methodology;
- Please, highlight limitations of your work in the Conclusion Section; - Please elaborate on the future research needs in this domain;
- Insert more data in the conclusions.
Author Response
Please see the attachment.
Author Response File: 
Author Response.pdf
Reviewer 2 Report
Thank you for giving me this chance to review this manuscript entitled (Identifying the Factors Contributing to Freeway Crash Severity Based on Discrete Choice Models). I hope authors do not be offended by my comments which only were raised to help them improve the quality of the manuscript to be at the publication level. The manuscript discussed a very important issue that is related to road safety. However, the manuscript's organisation needs to be reconsidered and heavily revised.
- The method of the analysis did not mention in the abstract.
- In the first paragraph of the introduction, the author provided facts and statistics without references. The reference must be for each sentence author has written in the whole manuscript unless the sentence belongs to the authors.
- I can't find the difference in the meaning between lines 35-28 and lines 47-52.
- Academics have done numerous studies to examine freeway crash frequency (please cite all these studies.
- The introduction needs to rewrite following a scientific way. In the current situation not acceptable.
- Also, in the introduction, make your problem statement and gap so clear supported by important citations for related previous studies and make your contributions and differentiation clear.
- The last paragraph of the introduction describes the flow of the research; authors should follow the scientific manner of the papers such as introduction, literature review, method, results, discussion, and conclusion.
- The sentence in line 73 is repeated.
- In 74 authors wrote the many researchers, please cite these researchers.
- Part of the literature review needs improvement. Authors should draw a table at the end of the section to compare many models, then under this table, authors should write a summary of the literature review, and at the end of this summary, they should draw the model of their study. That will make their contributions very clear.
- Section 3 should be the methodology.
- In the part of the methodology, authors should describe the type of the current study, the tradition of the study and how they identify the study's sample size. Then they can write about Data Preparation and Description.
- Section 4, this part of the analysis and you can consider it as a method of analysis, not the method of the whole study.
- Section 5.2 should be the discussion.
- Line 472- 480 seems like a recommendation, so it is better to write your recommendations all together at the end of the discussion part.
- Line 510, who said this sentence? If did you get it from previous studies, please cite it.
- The conclusion is Ok; however, the authors should provide the theoretical and practical contributions of the study. Otherwise, there are many factors that need to include in the limitation of your study as human factors such as fatigue, low performance, vigilance and drivers' aggression.
Author Response
Please see the attachment.
Author Response File: Author Response.pdf
Reviewer 3 Report
This study explores discrete outcome models to identify significant variables under different severity of crashes that occurred on a freeway. Three well-defined and established discrete outcome models are applied, ordered logit, generalized ordered logit, and partial proportional odds models, and finally identified some important parameters that significantly impact crash severity accepting PPO model derivatives as the best-fitted method.
Methodologically the study is robust but widely used. Therefore, from the methodological point of view, the contribution is minuscule, except for a perfect application in a new dataset. However, the selected road environment is unique. There is also nobility in consideration of factors. The paper is well structured. Data, methodology, and discussions are well described except for a few minor flaws, as pointed out below:
The base case of the model parameter is not clear. Normally, the discrete outcome model presents the impact of a parameter concerning a base case. Better to have the base case in the Model table, say Table 5.
Many pieces of literature are reviewed. Gaps are mentioned. But some are not clear e.g., "However, there have been a limited number of quantitative studies that also covered four factors". The sentences need to be revised with clear explanations.
Discussion and concluding remarks are well described and logical except for recommendations for “drivers’ education and training”. It is not clear how the authors will defend this recommendation from the study results.
Some sentences are too long, and the meaning is not clear e.g., the 5th, 6th & 8th sentences of the abstract, introduction stating contribution, etc. Please review. In fact, the entire is recommended to do proof-editing by a professional editor.
Some references are missing, say, the 1st paragraph of the Introduction.
Author Response
Please see the attachment.
Author Response File: Author Response.pdf
Round 2
Reviewer 1 Report
1) The motivation is not clearly addressed. The relationship with the related works should be clearly specified. 2) Comparison with previous peer methods should be conducted, and new findings should be clearly addressed.
3) Please, add at least 5 references to support your points, for example the following:
1. 10.33889/IJMEMS.2021.6.1.022;
2. 10.1002/qre.2675
3. Integrated hazards method (IHM): A new safety allocation technique
Falcone, D., Di Bona, G., Duraccio, V., Silvestri, A. ,
Author Response
Point to point response
1. The motivation is not clearly addressed. The relationship with the related works should be clearly specified.
Response: In the introduction section, we provide a clearer description of the motivation section. and describe the relationship of this study with related studies.
2.Comparison with previous peer methods should be conducted, and new findings should be clearly addressed.
Response: We have revised the literature review section by comparing the methods of previous studies in a tabular format. In the discussion section, the new findings obtained from this study are described and compared with the findings of previous related studies.
3. Please, add at least 5 references to support your points, for example the following:
Response: Thank you for providing the references, we have added some of them where appropriate and have cited the references you provided as detailed in line 156.
Special thanks to you for your good comments.
Reviewer 2 Report
Actually, the authors have taken most of my comments seriously. However, they ignored comments no 10 and 16, although they have written that they had already considered the comments in the cover letter, while in the revised version, there is no change. These are important comments, and I hope the authors consider them.
Author Response
Point to point response
10. Part of the literature review needs improvement. Authors should draw a table at the end of the section to compare many models, then under this table, authors should write a summary of the literature review, and at the end of this summary, they should draw the model of their study. That will make their contributions very clear.
Response: We conclude the literature review with a table listing comparisons of relevant models and a paragraph summarizing the research review. The methodology used in this study is further derived.
16. The conclusion is Ok; however, the authors should provide the theoretical and practical contributions of the study. Otherwise, there are many factors that need to include in the limitation of your study as human factors such as fatigue, low performance, vigilance and drivers' aggression.
Response: We have added a description of the theoretical and practical contributions to the conclusion. In the limitations section, the possible adverse effects of neglecting factors including fatigue, low performance, vigilance and drivers' aggression on the study results are also explained.
