Influence Factor Analysis of Bicycle Free-Flow Speed for Determining the Design Speeds of Separated Bicycle Lanes

Round 1

Reviewer 1 Report

The manuscript is very interesting and can be improved by adjusting details

Include in the Introduction the most important findings; How did your results address the problem?

1. It is better to establish specific objectives
2. Line 83 indicates the use of two cameras. Shows what kind of cameras?
3. Review the formula (1), it's a definition, or it would be nice to indicate a reference
4. Provide more details about the software
5. Is it used to process the information "What version is it? Enter more details about the numeric job.
6. It would be good to include in the discussion other similar experiments to confirm experimentation before the conclusions
7. It is better to provide a more up-to-date bibliographic review. There are excellent, very current examples published on the subject of Information Journal. The article has no reference from the journal Information. Journal Information has excellent references related to the topic.

Author Response

Dear Professor,

We are truly grateful to your critical comments and thoughtful suggestions. Based on these comments and suggestions, we have made careful modifications on the original manuscript. All changes made to the text are highlighted in yellow. We hope the new manuscript will meet your requirements. Below you will find our point-by-point responses to your comments:

1. More specific objective is established, please see line 60-64.
2. A photo of the used camera in the study was added into Figure 1a and we describe it in line 121-122.
3. A related reference was indexed in 185.
4. For your suggestion 4 and 5, we describe our data work in part 3.1 data collection including collection, extraction, and summary. Specially, your concerns are in 3.1.2 data extraction.
5. To prove the validity of our data, we compared the results with a similar research. Please see line 171-173.
6. Introduction is reconstructed now and an individual literature review presents as Part 2.

Thank you again for your time and consideration.

Sincerely,

Authors

Reviewer 2 Report

The paper presents a study aimed at identifying the relationships between the speed of bicycles in free-flow conditions and some parameters, including the type of bike, age, lane width, etc. The paper also suggests speed limits according to lane width and type of bicycle (normal or electric bicycles).

The title and keywords are consistent with the content of the paper. The abstract is well structured, and numbers support the conclusions.

The study conducted in this work and the results obtained by the authors may be useful for defining new speed limits for sustainable mobility that has been enormously transforming in recent years thanks to the development of electric bicycles. The methodology for the collection and statistical analysis of data are, on the whole, sufficiently illustrated. However, the paper should be improved to provide more details about the procedure for data collection, improve the statistical analysis and highlight the limitations of this study.

Below there are some comments that may be helpful to authors in improving the quality of the paper.

Introduction

In the introduction, it would be interesting for the authors to extend state of the art by adding more recent articles that represent similar studies performed in other countries.

Methodology

The authors should provide more details regarding the setting developed for data collection.

Why was the marking tape divided into three parts? How were the individual widths defined? This part is not exact, probably an image would help to understand.

Figure 1 shows “section 2.25m” and Section 1.25m ” dimensions, but their meaning is not clear.

A concern of the reviewer is related to the fact that the road used for the data acquisition is characterized by many elements (eg traffic cones, marking tapes) that could affect the way cyclists drive and therefore the significance of the data collected.

If possible, it would be useful to provide some more information about the electric and traditional bicycles that have been taken over. It could perhaps be helpful to deepen the analysis of the collected data.

It is also useful to know the flow-rate, to understand if the free-flow condition is respected.

Authors should better explain why those specific speed-influencing factors were identified apriori.

Results and discussions

It would be useful to standardize the speed unit of measurement through the text (see, for example, Figure 2 and Table 1). Probably kph could be the best unit of measure since the limit speed is then indicated using this one.

The Gap parameter in table 5 should be defined in the text and therefore, more discussed.

In equation 2 only the type of bicycle is considered, which is the most influential parameter. Probably the lane width is another parameter to take into consideration because it characterizes the track.

The speed limits calculated in this paper, in a free-flow regime, should be discussed in the case of a different flow, which could be a more realistic scenario in many cities.

Conclusion

Authors should highlight the limitations of their study more. Considering a regime other than free-flow, future developments should be more extensive and not limited only to specific aspects of the research conducted in this work.

Author Response

Dear Professor,

We are truly grateful to your critical comments and thoughtful suggestions. Based on these comments and suggestions, we have made careful modifications on the original manuscript. All changes made to the text are highlighted in yellow. We hope the new manuscript will meet your requirements. Below you will find our point-by-point responses to your comments:

1. Data collection are described in detail, presenting as collection, extraction, and summary now.
2. In the end of the paper, the limitation were indicated, see 299-301.
3. Introduction is reconstructed now and an individual literature review presents as Part 2. Similar studies performed in other countries are added now.
4. A chart was added into Figure 1 shown as b and the related indications are in line 124-127.
5. Supplementary notes of “section 1 and 2” are in line 128, 129.
6. To prove the validity of our data, we compared the results with a similar research. Please see line 171-173.
7. more information about the electric and traditional bicycles are shown in Figure 3 now.
8. We defined one bicycle was in a free flow state when it met the following three conditions as shown in Figure 2. The evaluation condition are in line145-148.
9. In line 175-183, we indicates the reason why those specific speed-influencing factors were selected.
10. the speed unit of measurement have been standardized.
11. More discussions about velocity gaps in table 5 (now table 7) are in line 246-251.
12. We consider lane width in determining design speed of bicycle lanes and established two equations for lanes of ≤5 m and >3.5 m respectively.
13. We explain why Bicycle free flow speed were investigated in determining a design speed of bicycle facilities. Please see line 51-59.
14. More limitations of our study were described in line 298-301.

Thank you again for your time and consideration.

Sincerely,

Authors

Round 2

Reviewer 2 Report

The authors have addressed all the reviewer’s comments. The current version of the manuscript can be fully considered for the publication.