Research on the Deployment of Joint Dedicated Lanes for CAVs and Buses

Round 1

Reviewer 1 Report

 

Dear author(s),

Thank you for letting me read your interesting and ambitious piece on CAVs and dedicated lanes. The topic is of much interest to public planners and developers of autonomous vehicles. I have the following suggestions for changes:

 

·        The paper (including the abstract) is well written but contains several minor grammatical/editing/source errors and needs a proofread.

·        Some parts of the paper (especially the introduction) are “wordy” (using many words to describe something that can be conveyed more succinctly) and can/should thus be shortened. Another example of this is the problem description in 2.1 which overlaps too much with parts of the introduction. It is thus possible to cut down on the word count somewhat by removing minor sections or words.

·        The first section lacks sources. This is an opportunity to link your research to other current debates, recent studies or public trials. The discussion section can then link back to your use of those sources. However, this is just a suggestion.  

·        Verify the accuracy/utility of the disposition in the last section of the introduction.

·        2.2 some variables lacks a clear definition/source and is not in the list of variables. Furthermore, there seem to be a lack of sources next to some of the claims. Eg. Line 238, 239-240, 269 – If possible provide example sources.

·        2.4 Is a sentence missing or is it just the first letter of While?

·        Is Figure 3 necessary?

·        Considering that AV convoys are a likely early adoption scenario it would be interesting to have a brief discussion about the implications of the results for such scenarios of bus use (especially considering the increased frequency that you test in 4.3).

Author Response

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Author Response File: Author Response.pdf

Reviewer 2 Report

 

The authors have presented their study, which addresses the issue of heterogeneous traffic flows affecting the efficiency of Connected Autonomous Vehicles (CAVs) when they first enter the market and proposed a joint dedicated lane for CAVs and buses. The paper is well structured and well written. However, there are some comments on the improvement of the paper.

1.      The authors should present in a different section the existing literature review and not only in the introduction. In the new literature review section, the authors should present their methodological novelty. In addition, this paper needs more references.

2.      Some references were not presented in the manuscript (see page 5 line 242 and page 7 line 278).

3.      There are some typos in the manuscript (see for example page 9 line 315, page 17 line 448).

Author Response

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Author Response File: Author Response.pdf

Reviewer 3 Report

This paper considers the potential impact and effects of allowing CAVs to participate in urban bus lanes at a macro-level and micro-level. The literature review was thorough and balanced considering the scope and scale of the fast-growing body of research. The paper is well-written and organized with all arguments logically and clearly presented.

 

Figure 5’s clarity of the problem is appreciated, especially, when paired with the results of Figure 6. Alone, these two figures in the paper were significant to the clarity of the author(s) argument. We would like to thank the author(s) for their thoughtfulness and the outlining of their associated information of these figures.

 

The interpretations of their sensitivity analysis and results were thorough and well-executed. The percentage of the CAVs on the system and how it impacts the balance of the system as a whole was greatly appreciated.

 

Overall, this paper is a contribution to the literature and should be published with minor revisions. These revisions are itemized below:

 

1. Acronyms should be introduced prior to using them throughout the manuscript. Examples of not introduced acronyms are the following: BRT lanes (p.2, line 85), HV (p.3, line 114), SO (p.5, line 215), UE (p.5, line 216), and F-W algorithm (p.12, line 369).
2. Opening sentence (p.4, line 174-178) on the Problem Description is a bit difficult to follow. Please consider rephrasing this for clarity and brevity. Was there supposed to be a colon or a period? 
3. There is an unclear statement about “the previous analysis” (p.10, line 329). It is not clear to the reviewer which analysis you are referring to. 
4. Present the parameters alpha and beta earlier in the document. Currently, they are mentioned multiple times, but not until later in the manuscript are they explained sufficiently (p.9, line 310). For the purposes of the methodical approach and clarity, it would behoove the author(s) to move this explanation forward.
5. Missing reference (p.5, line 242). There is an error that says missing reference.
6. Missing equation reference (p.10, line 342). 
7. Missing x-axis label on Figure 7 (page 15). 
8. Missing the “w” in “while” (p.9, line 315).

Author Response

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Author Response File: Author Response.pdf

Reviewer 4 Report

This study proposes a joint dedicated lane to be used by both buses and CAVs. A bi-level optimization program is introduced and the proposed scheme is tested in a road network. Generally, the paper is well-written and the methods and results are well-presented. My main concerns are listed below;

- Objectives and contributions of this study should be clearly mentioned in the abstract and introduction.

- The terms HV, CV, BS (in line 56, line 230) should be introduced, i.e., the long names should be provided, in the beginning (in the introduction).

- Assumption 1 (line 211) – Are CAVs also providing "services"? Why this assumption is important? If the CAVs are private vehicles will that matter?

- Assumption 3 (line 218 - 221) - Why the number of lanes is considered 3? If it is 2 or 4, will the result change? Or the method cannot be applied to other lane numbers?

- Figure 7 - What does this Figure explain? The x-axis should be named.

- Figure 8 – Apparently, the costs haven’t changed much. Are these differences significant?

 

- Figures 9 and 10 – Name the x-axes.

Author Response

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Author Response File: Author Response.pdf

Round 2

Reviewer 4 Report

The authors have addressed the comments by the reviewer. The manuscript have also been improved.