Optimization of Signal Timing for the Contraflow Left-Turn Lane at Signalized Intersections Based on Delay Analysis
Round 1
Reviewer 1 Report
The paper entitled "Optimization of signal timing for the contraflow left-turn lane at signalized intersections based on delay analysis" analyzes a very interesting concept of treating left-turners at signalized intersections in oversaturated conditions. Occasional and partial use of the opposite direction for left turns is not a standard solution and requires a more detailed analysis, which the authors tried to do. In this sense, this paper represents an original contribution to considering delays at signalized intersections. The general structure of the article is clear and logical. However, certain elements need to be improved and corrected:
- When describing the EFL system, it would be good if the Authors show a picture of an existing intersection with such a system,
- A significant part of the text is not clearly written (sentences are too long, a period is missing at the end of the sentence, etc.), e.g. part of the text in lines 40-48, 57-67, 86-87, 94-97, 129-131.
- References need to be correctly displayed and cited. The reference number should appear next to the author's name when specific research is mentioned in the article for the first time. There is no need to repeat the author's name and the year of the paper at the end of the sentence.
- In lines 92, 98, and 101, indicate the reference next to the author's name.
- Table 1 is not mentioned anywhere in the text.
- It is necessary to describe Figure 2 in more detail. The legend should clarify what the displayed lines and marks represent.
- Figure 3 should be mentioned somewhere in the text. Also, the legend next to the picture needs to be added.
- In Figure 5, marking the approaches (e.g., EB, WB...) and mentioning these names in the rest of the text would be helpful.
- Table 2 is not mentioned anywhere in the text.
- In table 2 and in the text (lines 309-314), traffic load and saturation level are mentioned. The authors should explain in more detail the period of traffic recording, the number of vehicles, the number of left turns, etc.
- Figures 8 and 12 are not mentioned anywhere in the text.
- It is necessary to describe the differences between models I and II before line 345 to clarify the text that follows.
- Conclusions should be written more clearly and in more detail.
Author Response
Dear reviewer, please see the attachment for the response to your comments.
Author Response File: 
Author Response.pdf
Reviewer 2 Report
This manuscript mainly proposed a nonlinear optimization model is proposed for the relationship between the presignal start node of the left vehicle exit lane and the dissipation time of the left vehicle queue.The manuscript has clear ideas, complete structure and certain application value. However, there are still some deficiencies in the paper.
1. In terms of energy saving, we should consider the different fleet flow mode of the now popular electric vehicles and other new energy vehicles compared to the traditional vehicles.
2. The calculation method lacks some innovation, considering a simpler and more efficient method for calculation.
3. When calculating the exhaust emissions, the vehicle model is not different, and the error is relatively large.
4. Whether to open the left-turn lane should consider the driver's adaptability condition, and whether some guidance measures need to be considered.
5. We hope the author can exexplain in more detail how the experiment is carried out, including the setting of relevant parameters, etc and Please improve figure-10、figure-11、figure-12 again some more beautiful.
Author Response
Dear reviewer, please see the attachment for the response to your comments
Author Response File: Author Response.pdf
Round 2
Reviewer 1 Report
The authors have made necessary corrections and the paper can be accepted in this form.
Reviewer 2 Report
All the comments are worked out by the authors. And this edition of manuscript is appropriate for publishing.
