Spatiotemporal Context for Daylight Saving Time-Safety Interactions in the Contiguous United States

Round 1

Reviewer 1 Report (Previous Reviewer 1)

Comments and Suggestions for Authors

General comments
The manuscript was substantially improved and some chapters rewritten. The structure is fine with me. However, some further questions arose. 

Specific comments

Line 107: Author and Author [11] estimate [..] -> something missing here?

Line 345 to line 384: there are tables and figures in between the text.

Line 346: I do not understand the table. How are the mean values calculated? For fatalities – 1.1 at everage in neach crash? Similar to other variables. What are 903.91 licensed driver at average? Registered vehicles with a mean value? It is unclear how to read the table. Subsequent tables with similar comments.

Line 361: unclear what the figure shows. Decreasing number of licensed-drivers effect on fatalities by longitude. What does longitude indicate?

Author Response

General comments

The manuscript was substantially improved and some chapters rewritten. The structure is fine with me. However, some further questions arose.

Specific comments

Line 107: Author and Author [11] estimate [..] -> something missing here?

Not missing anymore.

Line 345 to line 384: there are tables and figures in between the text.

Tables and figures are not in between the text.

Line 346: I do not understand the table. How are the mean values calculated? For fatalities – 1.1 at everage in neach crash? Similar to other variables. What are 903.91 licensed driver at average? Registered vehicles with a mean value? It is unclear how to read the table. Subsequent tables with similar comments.

In order to make the tables more understandable, Table 2 from line 156 to line 174 on pages 5 and 6 in the data section is a data dictionary for the variables at the crash and state levels. Also, line 192 to line 204 on page 7 in the data section lists the independent variables at the crash level (n = 638,164) and line 206 to line 215 on page 7 in the data section lists the independent variables at the state level (n = 49). The column heading for the means in Table 3 is clearly labelled (M). To that end, mean values in Table 3 are calculated for each crash (n = 638,164) or state (n = 49). For fatalities, average fatalities for each crash (n = 638,164) are 1.10. Licensed drivers at average are 903.91 for each state (n = 49). The mean value for registered vehicles in Table 3 is 2,489,722.38 for each state (n = 49).

Line 361: unclear what the figure shows. Decreasing number of licensed-drivers effect on fatalities by longitude. What does longitude indicate?

Longitude indicates location from west to east in the contiguous United States. Line 327 to line 341 on page 9 and line 357 to line 359 on page 12 in the analysis section explain how the licensed-drivers-per-1,000-driving-age-population effect changes from western to eastern longitudes in the contiguous United States. On the one hand, fatalities are highest in western states where the licensed drivers (per 1,000 driving-age population) are less numerous such as in California. On the other hand, fatalities are highest in eastern states where licensed drivers (per 1,000 driving-age population) are more numerous such as in Vermont.

Reviewer 2 Report (Previous Reviewer 2)

Comments and Suggestions for Authors

Congratulation to the authors that the manuscript has been well improved and the all my comments have been addressed. I have no more comments.

Author Response

Congratulation to the authors that the manuscript has been well improved and the all my comments have been addressed. I have no more comments.

Thank you.

Reviewer 3 Report (Previous Reviewer 3)

Comments and Suggestions for Authors

I stand by my previous opinion:

"I rate the peer-reviewed article very highly. The authors have clearly described why they undertook an analysis of the number of traffic accidents during the Daylight Saving Time in the United States. In doing so, they conducted a very thorough literature study of the issue.

In the article, they very clearly and accurately described the results obtained from the statistical analyses they carried out for many of the variables they took for calculations."

In addition, the authors have taken my previous comments into account.

They have also revised other parts of their article, which has significantly improved its scientific quality.

Therefore, I believe that the article should be published immediately.

Author Response

I stand by my previous opinion:

"I rate the peer-reviewed article very highly. The authors have clearly described why they undertook an analysis of the number of traffic accidents during the Daylight Saving Time in the United States. In doing so, they conducted a very thorough literature study of the issue.

In the article, they very clearly and accurately described the results obtained from the statistical analyses they carried out for many of the variables they took for calculations."

In addition, the authors have taken my previous comments into account.

Thank you for your comments.

They have also revised other parts of their article, which has significantly improved its scientific quality.

Thank you.

Therefore, I believe that the article should be published immediately.

Thank you.

This manuscript is a resubmission of an earlier submission. The following is a list of the peer review reports and author responses from that submission.

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

The study analyses the effect of daylight saving time on the number of (fatal) road accidents. Your study is well written and the structure is well prepared. According to the literature, there is no significant effect on the number of fatalities. However, I believe that there is not much interest in this activity. I regret to have to reject the manuscript. 

Reviewer 2 Report

Comments and Suggestions for Authors

1、The manuscript excludes several counties due to time-zone changes or jurisdictional issues. While the authors justify this in the Data section, it is unclear how these exclusions affect the generalizability of the results. 

2. Including a technical roadmap would better clarify the paper's rationale.

  3 The manuscript focuses on annual DST effects but does not analyze the acute impacts of DST transitions , which is a critical gap in the literature. 

4. The decision to merge the Pacific and Mountain time zones due to small sample sizes may mask intra-zone heterogeneity.

5.While the policy implications highlight the importance of licensure and enforcement, they lack specificity tailored to the study’s spatiotemporal findings.

Reviewer 3 Report

Comments and Suggestions for Authors

I rate the peer-reviewed article very highly. The authors have clearly described why they undertook an analysis of the number of traffic accidents during the Daylight Saving Time in the United States. In doing so, they conducted a very thorough literature study of the issue.

In the article, they very clearly and accurately described the results obtained from the statistical analyses they carried out for many of the variables they took for calculations.

I believe that the article should be published in the journal Future Transportation, but with minor corrections because of my comments:

1. Please improve, if graphically possible, the readability of Figure 5.
2. Please have the authors expand the summary. It would also be interesting to answer the question whether it makes sense from a road safety point of view to make annual time changes.

Reviewer 4 Report

Comments and Suggestions for Authors

This paper offers an in-depth and systematic analysis of the relationship between Daylight Saving Time (DST) and fatal motor-vehicle crashes in the contiguous United States using a multilevel model approach, making significant contributions to the existing literature. 

The paper clearly articulates the impact of DST on traffic safety, especially in light of the roles played by time zones, latitude, and longitude, revealing the complexity of the issue. The literature review comprehensively summarizes relevant studies and establishes a solid foundation for the paper's innovative aspects. The data and methodology sections are precise and well-organized, with the application of the multilevel model effectively addressing the complex relationship between DST and crash frequency and severity. The analysis is insightful, providing valuable references for scholars and policymakers in the field. Overall, the paper makes an empirical contribution to the study of DST-safety interactions and is a valuable addition to the field. However, there are a few areas to consider:

1.The abstract lacks detailed results and analytical discussion; it would be beneficial to include concrete numerical analysis findings.

2.The literature review does not reconcile conflicting findings or propose a theoretical framework. Discuss potential reasons and explicitly state hypotheses.

3.A brief, more accessible explanation of why a multilevel model was chosen over other statistical methods could improve the clarity of this section. Additionally, discussing potential limitations of the data and methodology (e.g., geographic exclusions and the limitations of the FARS dataset) would be useful to add a critical dimension.

4.It would be helpful to discuss in more depth how multicollinearity and convergence problems were handled and how they affect the overall reliability of the model.

5.Policy recommendations (e.g., licensure limits) are not tightly linked to results (e.g., small DST effects).

6.Revise long sentences (e.g., "Scholarship to understand...") for conciseness.

7.Enhance the resolution of Figure 5.