Transferability of Safety Performance Functions: The Case of Urban Four-Lane Divided Roadways in Muscat
Round 1
Reviewer 1 Report
“Stay safe and well !”
Thank you for giving me the opportunity to review this wonderful manuscript. I was interested in this paper, which it presented the transferability of safety performance functions in Oman. Also, it was very interested in the highway safety manual for safety performance functions by the best model using the Poisson-Gamma regression technique.
Major Comments:
<muscat data description></muscat data description>
[Line 101-17] I am deeply concerned about your use of data from 10 years ago as you write this paper. I would expect that the transportation environment in Muscat has changed a lot over the past decade, but it will have a different impact from the results presented in this paper. If possible, please explain why the author was unable to present results using updated data within the last 3 years. (ex. 2018-2019 or 2010-2019)
Minor Comments:
[Line 44] Please remove the number and bracket in the figure 1.
<muscat data description></muscat data description>
[Line 119] Please change the number of the table and the ones in all tables after that.
<results and discussion></results and discussion>
[Line 246] What does 'Table 12-22 of the HMS' mean?
[Line 298] Plaese sort the letters spacing and the location of each compartment in Table 3.
Comments for author File: 
Comments.pdf
Author Response
Response to Reviewer’s Comments on the Manuscripts:
Manuscript ID: vehicles-1916694
Title: Transferability of Safety Performance Functions: The Case of Urban Four-Lane Divided Roadways in Muscat
Reviewer #1
“Stay safe and well !”
Thank you for giving me the opportunity to review this wonderful manuscript. I was interested in this paper, which it presented the transferability of safety performance functions in Oman. Also, it was very interested in the highway safety manual for safety performance functions by the best model using the Poisson-Gamma regression technique.
Major Comments:
<muscat data description></muscat data description>
[Line 101-17] I am deeply concerned about your use of data from 10 years ago as you write this paper. I would expect that the transportation environment in Muscat has changed a lot over the past decade, but it will have a different impact from the results presented in this paper. If possible, please explain why the author was unable to present results using updated data within the last 3 years. (ex. 2018-2019 or 2010-2019)
Response:
The authors wish to express their sincere appreciation to the learned reviewer for his/her comments. As may be well known to the reviewer, the highway geometry design variables for urban divided roads such as driveaway density, median width, and speed limit have not been changed over the past years. Hence, the parameters were used in the study. However, a recent paper in Muscat related to the current study has been added to the revised manuscript.
Minor Comments:
[Line 44] Please remove the number and bracket in the figure 1.
Response:
Response: As pointed out by the learned reviewer, the number and bracket is from the reference style showing the study where Figure 1 was gotten
<muscat data description></muscat data description>
[Line 119] Please change the number of the table and the ones in all tables after that.
Response:
Response: As recommended by the learned reviewer, the number of tables has been updated in the revised manuscript.
<results and discussion></results and discussion>
[Line 246] What does 'Table 12-22 of the HMS' mean?
Response:
Response:
As requested by the learned reviewer, the Table 12-22 of the HMS is a table in the Highway Safety Manual (HSM) as referenced in the text where we based our CMF values
[Line 298] Please sort the letters spacing and the location of each compartment in Table 3.
Response:
Response: As suggested by the learned referee, the letter spacing and the location of each compartment in Table 3 have been corrected in the revised manuscript.
Dear Editor,
The authors are highly thankful to the esteemed editor and learned reviewers for the consideration given to the manuscript. Your valuable suggestions and corrections have helped the authors to improve the quality of the paper and wish the paper to be accepted for publication in your respectful journal.
Yours Sincerely,
Dr. Khalid
Author Response File: 
Author Response.docx
Reviewer 2 Report
This manuscript attempted to develop a crash prediction model in Oman. Such a model is crucial in practice, and the demonstrated results will be useful. However, I have the following concerns.
1. Line 47 Please describe clearly “these research gaps.” The current description failed to show the gap clearly.
2. You have two “Table 1.”
3. Figure 2 can be deleted because it duplicates Table 1.
4. It may be better to explain equations (3), (4), (6), and (7) in the Method section.
5. Please add p-value and model performance measures for Table 2.
6. Discussion may be insufficient. Please discuss the limitation of your model. A comparison of your results with other studies may be useful.
7. References are incomplete. Most of them lack the Journal information.
Author Response
Response to Reviewer’s Comments on the Manuscripts:
Manuscript ID: vehicles-1916694
Title: Transferability of Safety Performance Functions: The Case of Urban Four-Lane Divided Roadways in Muscat
Reviewer # 2
This manuscript attempted to develop a crash prediction model in Oman. Such a model is crucial in practice, and the demonstrated results will be useful. However, I have the following concerns.
- Line 47 Please describe clearly “these research gaps.” The current description failed to show the gap clearly.
Response:
The authors wish to their gratitude to the esteemed reviewer for the time spent reviewing this manuscript. As suggested by the reviewer, clear and detailed studies related to this topic of discussion have been reviewed and the gap in the literature is highlighted in the revised manuscript.
- You have two “Table 1.”
Response:
As pointed out by the learned reviewer, the two tables have been merged for clarity in the revised, manuscript.
- Figure 2 can be deleted because it duplicates Table 1.
Response:
As suggested by the learned reviewer, Figure 2 has been deleted from the revised, manuscript.
- It may be better to explain equations (3), (4), (6), and (7) in the Method section.
Response.
As requested by the reviewer more detail about equations 3, 4, 6 and 7 have been added in the revised manuscript.
- Please add p-value and model performance measures for Table 2.
Response.
As requested by the reviewer, Table 2 only shows coefficients as explained in the text. However, p-values, and goodness-of-fit metrics are shown in Table 3
- 6. Discussion may be insufficient. Please discuss the limitation of your model. A comparison of your results with other studies may be useful.
Response.
As suggested by the reviewer, limitation of the model and comparison of the results have been added to the revised manuscript.
- References are incomplete. Most of them lack the Journal information.
Response:
As requested by the reviewer, this suggested made has been updated in the revised manuscript.
Dear Editor,
The authors are highly thankful to the esteemed editor and learned reviewers for the consideration given to the manuscript. Your valuable suggestions and corrections have helped the authors to improve the quality of the paper and wish the paper to be accepted for publication in your respectful journal.
Yours Sincerely,
Dr. Khalid
Author Response File: Author Response.docx
Reviewer 3 Report
This paper addresses the traffic safety problem in the city of Muscat. The results show that the Highway Safety Manual HSM calibrated safety performance functions SPFs provide the best fit of the data used, and would be the best SPFs for predicting collisions in the City of Muscat.
The topic is important and the study is interesting. I have some concerns: The traffic in the four-lane road from Figure 1 is not heavy. An explanation about the causes of traffic accidents in similar situations is necessary.
The data are more than ten years old, 2010-2011. If available, more recent information about crashes in Muscat must be added.
References must be improved.
For better justification of results, the proposed HSM must be compared to other related from other cities or countries.
The conclusions must be more focused on how to prevent traffic accidents in Muscat.
Author Response
Response to Reviewer’s Comments on the Manuscripts:
Manuscript ID: vehicles-1916694
Title: Transferability of Safety Performance Functions: The Case of Urban Four-Lane Divided Roadways in Muscat
Reviewer # 3
This paper addresses the traffic safety problem in the city of Muscat. The results show that the Highway Safety Manual HSM calibrated safety performance functions SPFs provide the best fit of the data used, and would be the best SPFs for predicting collisions in the City of Muscat.The topic is important and the study is interesting. I have some concerns: The traffic in the four-lane road from Figure 1 is not heavy. An explanation about the causes of traffic accidents in similar situations is necessary.
Response:
As suggested by the learned reviewer, Figure 1 has been replaced in the revised, manuscript
The data are more than ten years old, 2010-2011. If available, more recent information about crashes in Muscat must be added.
Response:
The authors wish to express their sincere appreciation to the learned reviewer for his/her comments. As may be well known to the reviewer, the highway geometry design variables for urban divided roads such as driveaway density, median width, and speed limit have not been changed over the past years. Hence, the parameters were used in the study. However, a recent paper in Muscat related to the current study has been added to the revised manuscript.
Refere
nces must be improved.
Response:
As suggested by the learned reviewer, the references have been updated and revised in the revised manuscript.
For better justification of results, the proposed HSM must be compared to other related from other cities or countries.
Response:
As suggested by the learned reviewer, the proposed HSM has been compared to other related countries in the revised manuscript.
The conclusions must be more focused on how to prevent traffic accidents in Muscat.
Response:
As recommended by the learned reviewer, the conclusion has been improved in the revised manuscript.
Dear Editor,
The authors are highly thankful to the esteemed editor and learned reviewers for the consideration given to the manuscript. Your valuable suggestions and corrections have helped the authors to improve the quality of the paper and wish the paper to be accepted for publication in your respectful journal.
Yours Sincerely,
Dr. Khalid
Author Response File: Author Response.docx
Round 2
Reviewer 2 Report
Thank you for your revision. It is satisfactory.
Reviewer 3 Report
Taking into consideration the revised version, the manuscript is very much improved and can be recommended for publication.
