Estimating Reduction Coefficients of Parking Allocation Based on Public Transportation Accessibility: A Case Study on Nanjing’s Central District

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

In this paper, a multinomial Logit model is built based on resident trip survey data, then to assess the cross-elasticity of public transport accessibility on the probability of car travel, after that explaining the relationship between public transport accessibility and parking allotment. The study on reducing parking allocation makes sense, However, there are still some deficiencies in the content.

1)the expression of ‘indicating that a decrease in public transport accessibility results in a corresponding decrease in parking allotment’ need to be considered. Generally, the higher the public transport accessibility is , the more convenient the trip. More over, it appears contrary to the evidence presented in Table 4.  

2) what is the source of table 2?

3)While the highlight of this paper is the massive base data, insufficient details are provided on the data processing methodology, for example, Mobile phone signaling data and Path planning data.

4) ‘public transport travel times between grid cells were obtained via the A map API, while inter-grid trip volumes were derived from mobile phone signaling data’, this expression lacks clarity, and a map API is very unclear to me.

Comments for author File: Comments.pdf

Author Response

Dear Reviewer, Thank you sincerely for your thorough and insightful comments on our manuscript titled "[Estimating Reduction Coefficients of Parking Allocation Based on Public Transport Accessibility: A Case Study in Nanjing Central District]" (ID: [sustainability-3634196]). We deeply appreciate the time and expertise you dedicated to evaluating our work. Your constructive feedback and valuable suggestions have not only strengthened the clarity and rigor of the paper but also provided meaningful guidance for refining our research framework. We are truly grateful for your thoughtful critique. Your efforts have significantly contributed to improving the quality of this work, and we look forward to addressing your recommendations in the revised manuscript. Once again, thank you for your invaluable contribution to the peer-review process.

Comments 1: The expression of ‘indicating that a decrease in public transport accessibility results in a corresponding decrease in parking allotment’ need to be considered. Generally, the higher the public transport accessibility is , the more convenient the trip. More over, it appears contrary to the evidence presented in Table 4. 

Response 1: Thank you for pointing this out. We agree with this comment. Therefore, we have revised the wording to better align with the relevant analysis content in Table 4. The term "public transport accessibility" is represented as "average public transport travel time" in this context. By approximating private car travel probability reduction as parking reduction, and then calculating cross elasticity through the multinomial logit model, we computed the reduction in private car travel probability under different reduction ratios of average public transport travel time, thereby deriving parking reduction results. Generally speaking, higher public transport accessibility enhances resident mobility convenience, though in specific cities, actual travel choices and their relationship with public transport accessibility still need to be determined through travel surveys.[Page 1, Line 19-21]

Comments 2: What is the source of table 2?

Response 2: Thank you for pointing this out. We agree with this comment. Therefore, we have incorporated relevant explanations in the paragraph preceding Table 2. The table is derived from specific indicators in the household travel survey data, with a focus on metrics closely aligned with this study. Gender, Age, Educational attainment, and Occupation were included as classic socioeconomic attributes likely to influence travel choices; Driver’s license possession directly determines an individual’s capability for private car travel; IC card possession indicates willingness to use public transportation; Travel purpose reflects sensitivity to travel costs during trips; while Travel cost and Travel time serve as the most direct metrics for evaluating trip expenses. [Page 5, Line 185-192]

Comments 3: While the highlight of this paper is the massive base data, insufficient details are provided on the data processing methodology, for example, Mobile phone signaling data and Path planning data.

Response 3: Thank you for pointing this out. We agree with this comment. Therefore, we have revised the subsection title from "2.2 Data" to "2.2 Data and Processing", with expanded emphasis on data processing protocols—particularly for mobile phone signaling data and route planning data—to clarify methodological transparency.[Page 4, Line 121&128-132&137-140]

Comments 4:  ‘public transport travel times between grid cells were obtained via the A map API, while inter-grid trip volumes were derived from mobile phone signaling data’, this expression lacks clarity, and a map API is very unclear to me.

Response 4: Thank you for pointing this out. We agree with this comment. Therefore, we have revised the descriptions regarding the acquisition methods for inter-grid public transport travel times and trip volumes. Amap, the dominant mapping service provider in China, serves as the domestic counterpart to Google Maps in other countries. We sincerely apologize for not addressing Amap’s limited international recognition during the initial manuscript preparation. To enhance clarity, we have supplemented the explanation of how public transport travel times were retrieved via Amap’s API, with detailed elaboration provided in Section 2.2. [Page 5, Line 170-173]

Reviewer 2 Report

Comments and Suggestions for Authors

This paper proposed an estimation approach for reduction coefficients of parking allocation based on public transport accessibility. Also, an empirical study is conducted in Nanjing’s central urban area.

1. The author should further demonstrate this view in the related work: the calculation of reduction coefficients lacks scientific rigor. This is also the motivation of this paper.
2. The author should add a transitional paragraph (such as 2 and 2.1) between different levels of titles to illustrate the theme of this chapter or section and help readers better understand the full text.
3. Is the method in this paper universal, such as successfully moving to Beijing, Xi 'an and other cities？
4. In reality, there maybe an alternative relationship among walking, non-montor vehicles, et al.  Will this affect the conclusion of this paper？

Comments on the Quality of English Language

The English could be improved to more clearly express the research. Especially in the form of this paper.

Author Response

Dear Reviewer, Thank you sincerely for your thorough and insightful comments on our manuscript titled "[Estimating Reduction Coefficients of Parking Allocation Based on Public Transport Accessibility: A Case Study in Nanjing Central District]" (ID: [sustainability-3634196]). We deeply appreciate the time and expertise you dedicated to evaluating our work. Your constructive feedback and valuable suggestions have not only strengthened the clarity and rigor of the paper but also provided meaningful guidance for refining our research framework. We are truly grateful for your thoughtful critique. Your efforts have significantly contributed to improving the quality of this work, and we look forward to addressing your recommendations in the revised manuscript. Once again, thank you for your invaluable contribution to the peer-review process.

Comments 1:The author should further demonstrate this view in the related work: the calculation of reduction coefficients lacks scientific rigor. This is also the motivation of this paper.

Response 1: Thank you for pointing this out. We agree with this comment. Therefore, we have further clarified the issues inherent in existing methods for calculating reduction coefficients and establishing reduction criteria in the section of the Introduction, and have explicitly stated that the primary motivation of this study is to enhance the scientific rigor and methodological soundness in the computation of reduction coefficients. [Page 2, Line 72-79]

Comments 2:The author should add a transitional paragraph (such as 2 and 2.1) between different levels of titles to illustrate the theme of this chapter or section and help readers better understand the full text.

Response 2: Thank you for pointing this out. We agree with this comment. Therefore, we have added transition paragraphs between section headings at various levels (e.g., Sections 2 and 2.1, 3 and 3.1, 4 and 4.1) to provide a concise overview of each chapter’s key content, thereby enhancing reader comprehension of the study’s structure and analytical progression. [Page 3, Line 98-105; Page 5, Line 150-158; Page 7, Line 227-234; Page 10, Line 320-328]

Comments 3: Is the method in this paper universal, such as successfully moving to Beijing, Xi 'an and other cities?

Response 3: Thank you for pointing this out. We agree with this comment. Therefore, we have addressed your inquiry as follows: This study establishes a comprehensive methodological framework, empirically applied using Nanjing as a case study. Since the core data originates from urban resident travel surveys and mobile phone signaling data, with route planning data derived by identifying OD point coordinates from mobile signaling data and retrieving travel path details via the Amap API, the framework can be empirically applied to other cities, though outcomes may vary across cities due to localized contextual factors. [Page 13, Line 402-410]

Comments 4: In reality, there maybe an alternative relationship among walking, non-montor vehicles, et al.  Will this affect the conclusion of this paper?

Response 4: Thank you for pointing this out. We agree with this comment. Therefore, we have addressed your inquiry as follows: This study employs a multinomial logit model encompassing all travel modes—walking, non-motorized transport, public transport, private car, and modes—while incorporating both socioeconomic attribute variables and travel behavior characteristic variables. The results inherently account for substitution patterns between travel modes, thus preserving the validity of our conclusions. However, we acknowledge limitations at the micro-level, such as insufficient granularity in individual resident specificity and unmeasured psychological factors influencing mode choices. Adopting more precise survey methods (e.g., interviews or similar qualitative approaches) for targeted neighborhoods could better elucidate and interpret these substitution dynamics.

Reviewer 3 Report

Comments and Suggestions for Authors

The manuscript presents a well-structured and methodologically rigorous approach to estimating parking allocation reduction coefficients based on public transport accessibility, using Nanjing as a case study. The combination of accessibility modeling (via weighted average travel time), multinomial logit modeling, and elasticity analysis offers a valuable contribution to urban transport planning literature, particularly in advancing data-driven, context-sensitive parking policies. However, several aspects warrant attention and improvement before the manuscript can be considered for publication:

Firstly, the elasticity estimates are derived from travel survey data collected prior to the COVID-19 pandemic. Given potential shifts in travel behavior post-pandemic, the authors should more explicitly discuss how this temporal gap might affect the robustness or applicability of the estimated coefficients—particularly if the findings are to inform near-term policy.

Secondly, the integrated approach combining zonal classification and metro proximity is commendable. However, the paper would benefit from a more concrete discussion of how municipalities could implement these findings. For instance, what kind of institutional or regulatory adjustments would be needed to apply the reduction coefficients? Are there precedents from other cities?
Also, in the Discussion section, multiple consecutive paragraphs begin with similar transitional phrases such as “Furthermore” and “Moreover”. This repetition creates a monotonous tone and weakens the rhetorical flow of argumentation. 

Thirdly, some figures (e.g., Figures 2 and 3) are difficult to interpret due to unclear legends or insufficient contrast in shading. Enhancing the visual clarity and labeling of these maps would improve comprehension, especially for readers in practice-oriented fields.

Finally, some figures (e.g., Figures 2 and 3) are difficult to interpret due to unclear legends or insufficient contrast in shading. Enhancing the visual clarity and labeling of these maps would improve comprehension, especially for readers in practice-oriented fields. 

Comments on the Quality of English Language

Overall, the manuscript is well-written and professionally structured. However, minor polishing could improve clarity.

Author Response

Dear Reviewer, Thank you sincerely for your thorough and insightful comments on our manuscript titled "[Estimating Reduction Coefficients of Parking Allocation Based on Public Transport Accessibility: A Case Study in Nanjing Central District]" (ID: [sustainability-3634196]). We deeply appreciate the time and expertise you dedicated to evaluating our work. Your constructive feedback and valuable suggestions have not only strengthened the clarity and rigor of the paper but also provided meaningful guidance for refining our research framework. We are truly grateful for your thoughtful critique. Your efforts have significantly contributed to improving the quality of this work, and we look forward to addressing your recommendations in the revised manuscript. Once again, thank you for your invaluable contribution to the peer-review process.

Comments 1: Firstly, the elasticity estimates are derived from travel survey data collected prior to the COVID-19 pandemic. Given potential shifts in travel behavior post-pandemic, the authors should more explicitly discuss how this temporal gap might affect the robustness or applicability of the estimated coefficients—particularly if the findings are to inform near-term policy.

Response 1: Thank you for pointing this out. We agree with this comment. Therefore, in the Discussion section, we have cited a 2024 study investigating pre- and post-pandemic travel behavior, which demonstrated that private automobile travel patterns exhibited virtually no changes between the pre- and post-pandemic periods. [Page 13, Line 432-436]

Comments 2: Secondly, the integrated approach combining zonal classification and metro proximity is commendable. However, the paper would benefit from a more concrete discussion of how municipalities could implement these findings. For instance, what kind of institutional or regulatory adjustments would be needed to apply the reduction coefficients? Are there precedents from other cities?

Response 2: Thank you for pointing this out. We agree with this comment. Regrettably, no precedents currently exist in other cities, as advancing this initiative necessitates coordinated efforts across multiple departments. However, Nanjing is in the process of formulating a 2025 parking allocation reduction scheme for urban public buildings. By integrating our research with the latest practical developments, targeted studies on institutional or regulatory adjustments can be conducted based on implementation outcomes once the scheme is officially enacted. In subsequent research, we will explicitly incorporate policy implementation considerations.

Comments 3: Also, in the Discussion section, multiple consecutive paragraphs begin with similar transitional phrases such as “Furthermore” and “Moreover”. This repetition creates a monotonous tone and weakens the rhetorical flow of argumentation.  

Response 3: Thank you for pointing this out. We agree with this comment. Therefore, we have revised the transitional phrases between paragraphs to enhance textual coherence and logical flow. [Page 13, Line 422&429]

Comments 4: Thirdly, some figures (e.g., Figures 2 and 3) are difficult to interpret due to unclear legends or insufficient contrast in shading. Enhancing the visual clarity and labeling of these maps would improve comprehension, especially for readers in practice-oriented fields.

Response 4: Thank you for pointing this out. We agree with this comment. Therefore, we have optimized the figures in the manuscript to enhance visual clarity and readability. [Page 4&8&12]

Comments 5: Finally, some figures (e.g., Figures 2 and 3) are difficult to interpret due to unclear legends or insufficient contrast in shading. Enhancing the visual clarity and labeling of these maps would improve comprehension, especially for readers in practice-oriented fields.

Response 5: Thank you for pointing this out. We agree with this comment. Therefore, we have optimized the figures in the manuscript to enhance visual clarity and readability. [Page 4&8&12]

Round 2

Reviewer 3 Report

Comments and Suggestions for Authors

I sincerely appreciate the authors' thoughtful and comprehensive responses to the initial review. The revised manuscript demonstrates clear improvements in both structure and clarity, and the authors have addressed each point with care and rigor.