Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

The manuscript presents a novel and relevant approach to quantifying the geospatial burden associated with providing transportation to older adults. By applying activity space methodologies (SDE1 and RNB), the authors propose three innovative indicators for assessing the geospatial component of caregiving burden. The topic is timely, relevant to aging societies, and important for transportation and social policy research.

The study demonstrates clear novelty by integrating geographic information systems with caregiving research. The proposed burden indicators (A, B, C) constitute an original methodological contribution. The research addresses an evident gap in the literature: the lack of spatially explicit measures of transportation burden among caregivers.

The topic is highly relevant in the context of aging populations and unmet mobility needs. The manuscript could be strengthened by referencing research on active ageing environments, such as Dawidowicz et al. (2020), Alidoust et al.(2019), to situate the work more firmly within the broader field of age-friendly and mobility-supportive urban spaces.

The research problem is clearly stated. The aims are well defined; however, no explicit research hypotheses or research questions are formulated, which weakens methodological coherence. Even in exploratory studies, presenting guiding questions would help frame the analytical choices and interpretation.

The methodology is appropriate, transparent, and carefully described.
Strengths include: clear operationalisation of activity spaces, consideration of frequency-weighted destinations, detailed GIS procedures, appropriate use of non-parametric statistics. However, I also notice some weaknesses e.g., small sample size (N=18), limiting statistical inference, the dual approach (SDE1 vs. road network buffers) may reduce comparability across participants, lack of hypotheses or research questions. There is also a lack of explicit justification for selecting Vietnamese caregivers as the study population.
While the manuscript clearly states that participants were Vietnamese adults recruited through a community organization, the rationale for choosing this specific ethnic group is not fully articulated. The explanation remains primarily practical (availability, community partnership) rather than conceptual or empirical. To strengthen the manuscript, the authors should provide a clearer justification for why Vietnamese caregivers constitute an appropriate pilot population—e.g., whether this group has unique caregiving patterns, mobility challenges, cultural expectations regarding elder care, or transportation disparities documented in prior research. Even a brief reference to existing literature on ethnic differences in caregiving practices or mobility needs would enhance the transparency and transferability of the study design.

Results are clearly presented through tables, maps, and textual descriptions.
Interpretation is consistent with the data and appropriately cautious.
The identification of Burden Indicator B as the most robust measure is substantive and well supported.

Adding additional map elements (scale bar, clearer context layers) would enhance the clarity of spatial outputs.

Conclusions are reasonable, grounded in results, and appropriately modest.
Limitations and recommendations for future research are clearly articulated.

Final recommendation: Accept with minor revisions

Alidoust, S., Bosman, C., & Holden, G. (2019). Planning for healthy ageing: How the use of third places contributes to the social health of older populations. Ageing & society, 39(7), 1459-1484.

Dawidowicz, A., Zysk, E., Figurska, M., Źróbek, S., & Kotnarowska, M. (2020). The methodology of identifying active aging places in the city-Practical application. Cities, 98, 102575.

Author Response

We appreciate your support of this manuscript and your helpful suggestions. We made the following revisions in response to your main comment and suggestions.

Comment 1:  I also notice some weaknesses e.g., small sample size (N=18), limiting statistical inference, the dual approach (SDE1 vs. road network buffers) may reduce comparability across participants, lack of hypotheses or research questions

Response to Comment 1: We agree with these weakness and have emphasized them in the Discussion/Limitations section of the manuscript. 

Suggestion 1: The manuscript could be strengthened by referencing research on active ageing environments, such as Dawidowicz et al. (2020), Alidoust et al.(2019), to situate the work more firmly within the broader field of age-friendly and mobility-supportive urban spaces.

Response 1: Thank you for this helpful suggestion. We have included a these references in our introduction to emphasize the importance of active aging and access to community spaces.

Suggestion 2: While the manuscript clearly states that participants were Vietnamese adults recruited through a community organization, the rationale for choosing this specific ethnic group is not fully articulated. The explanation remains primarily practical (availability, community partnership) rather than conceptual or empirical. To strengthen the manuscript, the authors should provide a clearer justification for why Vietnamese caregivers constitute an appropriate pilot population—e.g., whether this group has unique caregiving patterns, mobility challenges, cultural expectations regarding elder care, or transportation disparities documented in prior research. Even a brief reference to existing literature on ethnic differences in caregiving practices or mobility needs would enhance the transparency and transferability of the study design.

Response 2: We have added more details about the parent study, the rationale for focusing on Vietnamese immigrants, and the context of unmet travel needs and caregiving among Vietnamese immigrants. While we agree it is important to add context to the study sample, we also want to keep the focus of this paper on the methods and the potential to use geospatial assessment of ride-providing burden across groups. As a result, we included this information in the methods when introducing the original, parent study rather than including a separate subsection in the Introduction about older Vietnamese immigrants. 

Suggestion 3: Adding additional map elements (scale bar, clearer context layers) would enhance the clarity of spatial outputs.

Response 3: We appreciate this suggestion for more clear spatial outputs and have revised the maps in the manuscript. After these revisions, each map has a scale bar in the lower left hand  corner. We have also emphasized the county boundaries and added county names to provide another way to reflect the scale of the map. Other elements added to the maps include labels indicating the type of activity for destinations and shadings/coloration to indicate frequency of activities at each destination in Figure 1 and Figure 2. We have left Figure 3 mostly unrevised because the intent of this figure it to provide a clear visualization of how each burden indicator was calculated rather than to impart spatial information. 

 

Reviewer 2 Report

Comments and Suggestions for Authors

This manuscript is innovative, but the content and method is simply. The problems are as follow:

1.The research object is blur. In introduction,the authors mentioned American disability act. However, this research is old people rather than disability old adults. It is confuse that the driver have burden of providing rides to older adults. If the older adults have ability to move by themselves. They are the same as young passengers.

2.What's your study area? 

3.What's the significance of your research? Help release the burden of ride provider? or improve the accessibility of old adults?

4.The conclusions only present the research progress, the core finding is not shown.

5.The points are too less, the standard deviation ellipse is difficult to reflect the trusted results.

Comments on the Quality of English Language

The English should be polished. There have several grammar errors.

Author Response

Thank you for your time and attention for reviewing this manuscript. Below we provide our responses to your comments. 

Comment 1: What's your study area?

Response 1: We have ensured the methods clearly state that the research was conducted in the Dallas-Fort Worth, Texas metroplex in the United States.

Comment 2: What's the significance of your research? Help release the burden of ride provider? or improve the accessibility of old adults?

Response 2: In section 1.4, we have clarified that the long term goal of the research is to both support ride providers as well as improve mobility for older adults. 

Comment 3: The research object is blur. In introduction,the authors mentioned American disability act. However, this research is old people rather than disability old adults. It is confuse that the driver have burden of providing rides to older adults. If the older adults have ability to move by themselves. They are the same as young passengers

Response 3: We have added clarifying information about ADA and paratransit services to highlight that although this is the only federal response that addresses transportation needs of many older adults, it is not comprehensive and thus, there is a reason to consider other policy options. We have also added a bit more context to the concept of older adults as recipients of rides from others. 

Comment 4: The conclusions only present the research progress, the core finding is not shown.

Response 4: We have lengthened and, we believe, strengthened the conclusion section considerably. Part of this revision included making sure that the core finding of the study was reiterated in the conclusion.

Comment 5: The English should be polished. There have several grammar errors.

Response 5: We have carefully proofed the manuscript and corrected any grammatical errors found.

Comment 6: The points are too less, the standard deviation ellipse is difficult to reflect the trusted results.

Response 6: Our exemplar maps reflect a typical participant in the study. The majority of participants did not have a tremendous amount of destinations in their activity spaces. However, we have added labels for the points in the map and have shaded by frequency of going to the destination in order to add increased clarity and trust regarding the construction of the ellipses. 

 

Reviewer 3 Report

Comments and Suggestions for Authors

Review Comments on “Quantifying the geospatial burden of providing rides to older adults using activity spaces and geographic information systems”

1. Summary

This study proposes a GIS and activity space theory-based approach to quantify the geospatial burden experienced by ride providers. By comparing ride providers’ “regular activity space” with their “ride-provision activity space,” the authors construct three geospatial burden indicators. Using pilot data from 18 Vietnamese ride providers in the Dallas-Fort Worth, Texas area, preliminary results suggest that Burden Indicator B (the percentage of ride-provision activity space exceeding the regular activity space) shows the strongest correlation with other burden dimensions and may be an effective indicator for quantifying geospatial burden.

2. Major Strengths

• Novel and Significant Research Topic: In the context of global population aging, this study focuses on the burden experienced by ride providers—a unique perspective with important practical and policy implications. Applying activity space theory to quantify transportation burden overcomes the limitations of traditional self-report scales and provides an objective GIS-based measurement tool for this field.

• Strong Methodological Innovation: The paper proposes three burden indicators based on spatial overlap (area, percentage of inaccessible area, and ratio), with rigorous logic and clear concepts. Transforming the abstract concept of “burden” into quantifiable spatial indicators is a creative contribution. The figures (Figures 1-3) effectively illustrate the core concepts.

• Well-Organized Manuscript: The paper has a complete structure with clear arguments. The introduction effectively establishes the research necessity, while the discussion section candidly reflects on limitations and proposes future research directions.

3. Major Revisions Required

• Small Sample Size and Its Impact on Conclusions: This is the most significant limitation of the study. With N=18, the sample size is very small for correlation analysis, resulting in extremely low statistical power and severely limiting the robustness and generalizability of the conclusions. While the authors acknowledge this limitation in the discussion section, more cautious language is needed in the results presentation and discussion. For example, the statement in the conclusions that “Burden Indicator B…outperformed the other burden indicators” may be too absolute. I recommend revising it to “…showed the most promising results in this exploratory study” or similar wording to emphasize its preliminary and exploratory nature.

• Inconsistency in Activity Space Construction Methods: The methodology indicates that for participants with more than two destinations (n=12), the Standard Deviational Ellipse (SDE1) was used to construct activity spaces, while for participants with only two destinations (n=6, one-third of the sample), a half-mile Road Network Buffer (RNB) was employed. SDE is an unconstrained geometric shape based on point distribution, whereas RNB is a network-constrained shape based on actual road networks—these two approaches differ fundamentally in concept and form. Combining activity space data constructed using these two distinctly different methods for unified analysis raises questions about validity. The authors need to:

  • 1. Provide detailed justification for why these two methods must be mixed.
  • 2. Analyze the potential bias this mixed-method approach may introduce to the research results (especially the calculation of the three burden indicators).
  • 3. Discuss this issue more thoroughly in the limitations section and suggest how future research should unify the methodology.

• Lack of Context on Data Collection Period: The methods section states that data were collected from July 2020 to January 2021. This was the peak period of the global COVID-19 pandemic, when social travel patterns were severely disrupted (e.g., remote work, social restrictions). This critical contextual information is completely absent from the manuscript. The pandemic likely had a profound impact on both ride providers’ and older adults’ routine activities and travel needs, potentially distorting the true forms of both “regular activity space” and “ride-provision activity space.” The authors must explicitly address this issue in the limitations section and discuss its potentially far-reaching impact on the research results.

4. Minor Revisions Required

• Oversimplified Measure of “Impact”: The manuscript treats “whether negative impacts were experienced” as a binary variable (yes/no). This approach equates impacts of vastly different magnitudes (e.g., spending $10 per month on transportation costs vs. missing work and experiencing significant stress due to providing rides), losing substantial information. I recommend the authors acknowledge this limitation in the discussion and suggest that future research could employ more refined measurement approaches, such as Likert scales or composite scoring.

• Clarification of Methodological Details:

  • When calculating activity spaces, why was the home address weighted as “30 days” (line 328)? Please provide theoretical or practical justification for this specific value.
  • The note to Table 4 mentions that the correlation analysis involving “days per month giving rides” was based on n=13. I recommend briefly explaining in the main text why 5 participants were missing data for this key variable.

• Lack of Clarity on Caregiving Relationships: The methods section (lines 217-228) mentions that the recruitment criterion for ride providers was “providing rides to Vietnamese older adults aged 65 and older,” but does not clarify the relationship between ride providers and care recipients (e.g., family members, friends, neighbors). The literature review section (lines 96-103) indicates that different types of caregivers (e.g., adult children, spouses, other family members, friends) may experience different burdens and have different caregiving patterns. Table 1 presents demographic characteristics of ride providers but lacks descriptive statistics on caregiving relationships, making it difficult for readers to understand sample representativeness and the generalizability of the research findings. I recommend:

  • 1. Clarifying in the methods section whether data on caregiving relationships were collected.
  • 2. If such data were collected, presenting descriptive statistics in the results section.
  • 3. Discussing in the discussion or limitations section how caregiving relationships might affect the perception and measurement of geospatial burden.

5. Overall Evaluation

In summary, this is a highly original and important exploratory study. It successfully provides a novel theoretical framework and operational method based on geospatial analysis for quantifying transportation caregiving burden. Although the study has obvious limitations due to small sample size, mixed methodology, and failure to account for the pandemic context, its exploratory value should not be overlooked. The concepts and methods proposed in this manuscript lay a solid foundation for future large-sample studies.

Recommendation: Accept with Major Revisions

The authors need to carefully address the above major revision recommendations, particularly regarding sample size, activity space construction methodology, and the pandemic context. With more conservative and rigorous language regarding the research conclusions, this manuscript has the potential to become an important contribution to the intersection of geographic information science and aging research.

Comments for author File: Comments.pdf

Author Response

Thank you so much for your careful review of our manuscript. You provided helpful suggestions, which we have addressed, and believe the manuscript is much improved. Below is an itemized account of your comments and our responses.

Comment 1: Small Sample Size and Its Impact on Conclusions: This is the most significant limitation of the study. With N=18, the sample size is very small for correlation analysis, resulting in extremely low statistical power and severely limiting the robustness and generalizability of the conclusions. While the authors acknowledge this limitation in the discussion section, more cautious language is needed in the results presentation and discussion. For example, the statement in the conclusions that “Burden Indicator B…outperformed the other burden indicators” may be too absolute. I recommend revising it to “…showed the most promising results in this exploratory study” or similar wording to emphasize its preliminary and exploratory nature.

Response 1: We appreciate this recommendation and agree with the reviewer about the limitations of the sample size. We have revised the sentence as suggested. In addition, we have added language to the limitations section emphasizing the significance of the limitation.

Comment 2: Lack of Context on Data Collection Period: The methods section states that data were collected from July 2020 to January 2021. This was the peak period of the global COVID-19 pandemic, when social travel patterns were severely disrupted (e.g., remote work, social restrictions). This critical contextual information is completely absent from the manuscript. The pandemic likely had a profound impact on both ride providers’ and older adults’ routine activities and travel needs, potentially distorting the true forms of both “regular activity space” and “ride-provision activity space.” The authors must explicitly address this issue in the limitations section and discuss its potentially far-reaching impact on the research results.

Response 2: Thank you for this insightful recommendation. We agree that the context of the pandemic is vital to fully contextualizing the research and have added information to the limitations section. 

Comment 3:  Inconsistency in Activity Space Construction Methods: The methodology indicates that for participants with more than two destinations (n=12), the Standard Deviational Ellipse (SDE1) was used to construct activity spaces, while for participants with only two destinations (n=6, one-third of the sample), a half-mile Road Network Buffer (RNB) was employed. SDE is an unconstrained geometric shape based on point distribution, whereas RNB is a network-constrained shape based on actual road networks—these two approaches differ fundamentally in concept and form. Combining activity space data constructed using these two distinctly different methods for unified analysis raises questions about validity. The authors need to:

• Provide detailed justification for why these two methods must be mixed
• Analyze the potential bias this mixed-method approach may introduce to the research results (especially the calculation of the three burden indicators).
• Discuss this issue more thoroughly in the limitations section and suggest how future research should unify the methodology.

Response 3: We have provided additional information about the differences in the activity spaces constructed using these two methods and results of a sensitivity analysis running the correlations separately for each sub=sample. In the Methods section we provided a rationale for why the two construction approaches were combined into one operationalization of the construct of "ride-provision activity space" and we return to this topic with a lengthy treatment in the Limitations section. 

Comment 4: Oversimplified Measure of “Impact”: The manuscript treats “whether negative impacts were experienced” as a binary variable (yes/no). This approach equates impacts of vastly different magnitudes (e.g., spending $10 per month on transportation costs vs. missing work and experiencing significant stress due to providing rides), losing substantial information. I recommend the authors acknowledge this limitation in the discussion and suggest that future research could employ more refined measurement approaches, such as Likert scales or composite scoring.

Response 4: We found this suggestion to also be quite helpful and have added specific information in the limitations section regarding potential approaches for understanding impacts in future research. 

Comment 5: When calculating activity spaces, why was the home address weighted as “30 days” (line 328)? Please provide theoretical or practical justification for this specific value.

Response 5: We added the rationale for considering the weight of home address to be 30 days in the Method section. 

Comment 6: The note to Table 4 mentions that the correlation analysis involving “days per month giving rides” was based on n=13. I recommend briefly explaining in the main text why 5 participants were missing data for this key variable.

Response 6: We have added the explanation of the lower n ("because of missing data for at least one of the ride destinations") to the note in Table 4. Because of the small sample and exploratory nature of the study, we decided to delete missing data pairwise rather than attempting to impute missing data.

Comment 7: Lack of Clarity on Caregiving Relationships: The methods section (lines 217-228) mentions that the recruitment criterion for ride providers was “providing rides to Vietnamese older adults aged 65 and older,” but does not clarify the relationship between ride providers and care recipients (e.g., family members, friends, neighbors). The literature review section (lines 96-103) indicates that different types of caregivers (e.g., adult children, spouses, other family members, friends) may experience different burdens and have different caregiving patterns. Table 1 presents demographic characteristics of ride providers but lacks descriptive statistics on caregiving relationships, making it difficult for readers to understand sample representativeness and the generalizability of the research findings. I recommend:

• Clarifying in the methods section whether data on caregiving relationships were collected
• If such data were collected, presenting descriptive statistics in the results section
• Discussing in the discussion or limitations section how caregiving relationships might affect the perception and measurement of geospatial burden.

Response 7: This is an important consideration that we originally omitted to address in the manuscript. Unfortunately, we failed to collect this information from the ride providers. We have made this clear in the Methods section by adding that eligibility to participate in the study was not related to relationship type and that information was not collected. In addition, we have added a recommendation in the limitations section to include relationship type in future studies.

Comment 8:  Recommendation: Accept with Major Revisions

The authors need to carefully address the above major revision recommendations, particularly regarding sample size, activity space construction methodology, and the pandemic context. With more conservative and rigorous language regarding the research conclusions, this manuscript has the potential to become an important contribution to the intersection of geographic information science and aging research.

Response 8: We appreciate your support for this manuscript. We have tempered our language in the Discussion and Conclusion sections, making sure to emphasize the exploratory nature of the research, its limitations, and the need for future research

 

 

 

Reviewer 4 Report

Comments and Suggestions for Authors

15 - receiving rides - I don't understand this formulation.

18, 23, 211, 217, 243, 290, 308, 315, 367, 486 – we apply,  we, we, we – please, use passive voice

34 - Medicare  - It must be written what it is.

61 - paratransit services - Why the prefix "para" ?

81 -  rides from others - Please explain what you mean by this.

88 -  geospatial burden - Why burden ?

191 – Burden - Burden sounds like a very difficult word to me. I think the word problem is more appropriate.

206 - pilot study – why pilot ? Habitually, pilot studies precede research.

207-209 The first was the activity space of their routine activities, an activity space that has commonly been used in previous research (Sherman et al., 2005, Szanton et al., 2023). - The same word three times in one sentence.

233 - Who financed the recruitment?

281-282 - The same word three times in one sentence.

411-413 - This part of the text needs to be clarified.

415 - There should be some scientific justification for limiting the sample to Vietnamese people. If there is no scientific significance, I don't understand why this characteristic is mentioned. I also don't understand why the authors didn't include subjects from other ethnic groups in their sample.

426 - It would be nice to express the values ​​in km as well.

558 - Why weakness? From whose perspective does this assessment come?

 

In this work the most valuable is effort.

This work is an idea, but the results themselves have only local significance.

The authors are aware of the limitations.

The study has citation potential, as the cohort studied is increasingly relevant, given the unstoppable process of demographic aging in the United States.

The conclusion is brief and it can be better.

Author Response

We thank you kindly for your careful review of the manuscript. We have your comments in the manuscript as explained below.

Comment 1: 15 - receiving rides - I don't understand this formulation.

Response 1: We have changed this sentence to read, "For older adults who do not or no longer drive, receiving getting private automobile rides from others is their primary mode of transportation" to increase clarity.

Comment 2: 18, 23, 211, 217, 243, 290, 308, 315, 367, 486 – we apply,  we, we, we – please, use passive voice

Response 2: We consulted previously published manuscripts in this journal as determined that the use of passive voice is not the customary style for academic writing. We prefer to retain the clarity of first person plural, yet will defer to the editor if they would like us to adopt passive voice instead of first person plural for this manuscript. 

Comment 3: 34 - Medicare  - It must be written what it is.

Response 3: We have added a description of Medicare in the Introduction. 

Comment 4: 61 - paratransit services - Why the prefix "para" ?

Response 4: An additional phrase was added to this sentence to explain that paratransit services are mandated in the same service areas as fixed routes. The name paratransit is proviced in the ADA legislation and was not created by the authors of this manuscript.

Comment 5: 81 -  rides from others - Please explain what you mean by this.

Response 5: We have changed this sentence to read, "riding with others in their automobiles (i.e., 'getting rides')"

Comment 6 and 7: 88 -  geospatial burden - Why burden ? // 191 – Burden - Burden sounds like a very difficult word to me. I think the word problem is more appropriate.

Response 6 and 7: In research, policy, and practice related to older adults, "caregiver burden" is a construct that is very common. This language will be familiar to practitioners in the field. // As discussed above, caregiver burden is a common construct in the discipline of gerontology. As an important audience for this research is practitioners, policy makers, and researchers in the field of aging-related research, we would like to keep this verbiage. 

Comment 8: 206 - pilot study – why pilot ? Habitually, pilot studies precede research.

Response 8: We have removed the word pilot from this sentence to clarify that the research was exploratory.

Comment 9: 207-209 The first was the activity space of their routine activities, an activity space that has commonly been used in previous research (Sherman et al., 2005, Szanton et al., 2023). - The same word three times in one sentence.

Response 9: This sentence has been reworded to remove the repetition of "activity space."

Comment 10: 233 - Who financed the recruitment?

Response 10: The funder has been acknowledged in the Funding section of the manuscript (before References). The funder was The National Institute of Transportation and Communities. 

Comment 11: 281-282 - The same word three times in one sentence.

Response 11: This sentence has been reworded to minimize the repetition of "rides."

Comment 12: 411-413 - This part of the text needs to be clarified.

Response 12: The automated formatting of the document added an unnecessary hyphen in the word "bias." We have corrected this and added (BCa) to help explain bias-corrected and accelerated.

Comment 13: 415 - There should be some scientific justification for limiting the sample to Vietnamese people. If there is no scientific significance, I don't understand why this characteristic is mentioned. I also don't understand why the authors didn't include subjects from other ethnic groups in their sample.

Response 13: The data for this study were originally collected as part of a survey research of older Vietnamese adults in the Dallas Fort Worth metroplex. We have added contextual information about the original study in Section 2, including a justification for the study population. 

Comment 14: 426 - It would be nice to express the values ​​in km as well.

Response 14: We provided values in km as well as miles throughout the results narrative.

Comment 15: 558 - Why weakness? From whose perspective does this assessment come?

Response 15: We have removed the passive voice from this sentence to clarify where the assessment came from and have changed "weakness" to "deficit" 

Comment 16: The conclusion is brief and it can be better.

Response 16: We have completely rewritten the conclusion to expand it, include more details about our findings and their implications, and emphasis the potential for geospatial approaches using activity spaces to assess the burden of providing rides to older adults. 

 

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

I recommend the article for publication.

Reviewer 2 Report

Comments and Suggestions for Authors

The authors have revised the mauscript carefully.  However, there still have many problems need to be revised.

1.The title is really mess. Maybe you want to express that Quantifying the Spatial Challenges of Transportation Services for Older Adults Using Activity Space Analysis and GIS? or A GIS-Based Approach to Quantifying the Activity Space Burden of Transportation Services for Older Adults. 

2.The last sentence of abstract. Maybe it is difficult to become your core conclusion.

3.The older adults is also an important keyword.

4.There have a very important problem.  A reference (sherman et al.,2005) was cited many times in your manuscript. There have many relevant references. For example,  the reference is suitable cited in line 162 as follow: Identifying urban agglomeration’s range: Integrating clustering and accessibility analysis. Cities, 2026,171:106708. doi:https://doi.org/10.1016/j.cities.2025.106708 The reference could be cited in line 197 as follow: Comparing circular and network buffers to examine the influence of land use on walking for leisure and errands. Int J Health Geogr,2007, 6, 41. doi:https://doi.org/10.1186/1476-072X-6-41

If the a reference repeat showed in the manuscript many times. I think the authors didn't read enough literature.

5. The conclusion is too long. I want to see your core results.

6.In general, the figures are in result section, and authors will analysed the results according to the figures. Why the figure 1-3 are in section method? Is it only used to enhance the understand of methods?

 

Comments on the Quality of English Language

The English should be polished. There have several grammar errors.

Author Response

Thank you for your continued review of this manuscript. We have responded to each of your specific comments below. In terms of overall rating that the manuscript needs improvement in its use of English language, we have taken several steps. First, the manuscript has been read in full by academic scholars who are native English speakers. Second, we have used AI tools (i.e., Grammarly, ChatGPT, and Google Gemini) to provide suggestions for improved grammar and clarity. Where feasible within the revised manuscript, we have highlighted these revisions in yellow. We have added an AI disclosure to the manuscript to acknowledge the AI usage.

Comment 1: The title is really mess. Maybe you want to express that Quantifying the Spatial Challenges of Transportation Services for Older Adults Using Activity Space Analysis and GIS? or A GIS-Based Approach to Quantifying the Activity Space Burden of Transportation Services for Older Adults. 

Response 1: We appreciate the reviewer’s suggestion and have revised the title to reflect the focus on informal ride provision and ride-provider burden, which are central to the study’s analytic approach.

Comment 2: The last sentence of abstract. Maybe it is difficult to become your core conclusion.

Response 2: As this is the finding for  our second, and most prominent, research question, we have retained this implication in the abstract. However, to keep the wording in alignment with the findings and discussion, we have added a reference to this being Burden Indicator B in the sentence. 

Comment 3: The older adults is also an important keyword.

Response 3: Thank you for your attention to this detail. We have added "older adults" to the list of key words and expect it will assist in searches. 

Comment 4: There have a very important problem.  A reference (sherman et al.,2005) was cited many times in your manuscript. There have many relevant references. For example,  the reference is suitable cited in line 162 as follow: Identifying urban agglomeration’s range: Integrating clustering and accessibility analysis. Cities, 2026,171:106708. doi:https://doi.org/10.1016/j.cities.2025.106708 The reference could be cited in line 197 as follow: Comparing circular and network buffers to examine the influence of land use on walking for leisure and errands. Int J Health Geogr,2007, 6, 41. doi:https://doi.org/10.1186/1476-072X-6-41. If the a reference repeat showed in the manuscript many times. I think the authors didn't read enough literature.

Response 4: The reliance on Sherman et al, 2005 was intentional as this is a foundational reference for activity spaces, particularly in public health. However, we agree that additional and/or more varied references can be included to show the use of activity space analysis in more recent years and have done so where relevant. The new references are highlighted in yellow within the revised manuscript. 

Comment 5: The conclusion is too long. I want to see your core results.

Response 5: We understand your sense that we have not hit the correct length and emphasis for the conclusion. As the conclusion is an optional section for this journal and we have already reiterated our key findings in the discussion section we have decided to remove the conclusion section from this manuscript and to instead conclude the manuscript with the future directions section of the Discussion. The core findings are retained in this Discussion section a separate heading and an added phrase to emphasize what we consider the core findings. We trust this streamlined approach, which is more in alignment with traditional recapping of findings in the Discussion, will allow the reader to absorb our key takeaways efficiently.

Comment 6: In general, the figures are in result section, and authors will analysed the results according to the figures. Why the figure 1-3 are in section method? Is it only used to enhance the understand of methods?

Response 6: Yes, the figures are solely to demonstrate the Methods and are not refelctions of results. As such, we will retain them in the methods sections. Our research questions rely on traditional statistical descriptive and bivariate approaches, which are presented in the Results in narrative and tabular formats. We have added a few words/phrases to the sentences that present each figure in text to emphasize that the figures are demonstrating methods, not findings. 

Reviewer 3 Report

Comments and Suggestions for Authors

Manuscript ID: ijgi-3973116

Title: Quantifying the geospatial burden of providing rides to older adults using activity spaces and geographic information systems

Current Status: Revised Version (v2)

1. General Evaluation

The manuscript has a clear structure and its main innovation lies in shifting from traditional survey-based judgments of burden for providing rides to older adults to a geospatial quantification method. The study constructs targeted indicators and possesses research value and significance.

2. Major Concerns

Based on the reviews from the previous round, one issue remains not fully resolved: the statistical validity of of mixed data. The authors admit in the paragraph starting at Line 446 that the sensitivity analysis "found similar results in terms of direction of correlation, though p-values changed."

This admission actually exposes a serious statistical flaw. The change in p-values (especially in a small sample of N=18) indicates that these two subgroups (SDE group and RNB group) have different statistical properties. Forcedly mixing geometrically incompatible data (planar ellipse vs. linear buffer) merely to increase sample size, while admitting that significance fluctuated, makes the subsequent correlation results unreliable.

3. Recommendation

Minor Revision

Requirement: The authors must separate the analysis. Do not mix SDE and RNB data in one model. Please present the analysis results for the SDE group (n=12) separately. If the sample size is too small to yield significance, then present it as descriptive data; do not force an incompatible correlation analysis.

Comments for author File: Comments.pdf

Author Response

Comment 1: The manuscript has a clear structure and its main innovation lies in shifting from traditional survey-based judgments of burden for providing rides to older adults to a geospatial quantification method. The study constructs targeted indicators and possesses research value and significance.

Response 1: Thank you for your supportive words and your helpful suggestions for this manuscript. We respond to your major concern below and would like to note that your contributions in this and the previous review have been most beneficial in improving this manuscript.

Comment 2: 

Based on the reviews from the previous round, one issue remains not fully resolved: the statistical validity of of mixed data. The authors admit in the paragraph starting at Line 446 that the sensitivity analysis "found similar results in terms of direction of correlation, though p-values changed." This admission actually exposes a serious statistical flaw. The change in p-values (especially in a small sample of N=18) indicates that these two subgroups (SDE group and RNB group) have different statistical properties. Forcedly mixing geometrically incompatible data (planar ellipse vs. linear buffer) merely to increase sample size, while admitting that significance fluctuated, makes the subsequent correlation results unreliable.

Response 2: We understand this concern and after careful consideration have decided to present findings from only the one standard deviation ellipse (SDE1) approach. After reflecting about our intial choices, we realized the main impetus behind combining the two measures into one analysis was to streamline our presentation of this new concept. By presenting only the sample with full data to construct SDE1s, we maintain this quality of a less complex methodological treatment to the idea of geospatial burden of providing rides. However, the constraint of not being able to construce SDE1s for ride providers who only provide to one location remains. We have therefore highlighted this in the limitations section (new paragraph is highlighted) and suggest that future research with larger samples use the road network buffer method for ride providers with only one ride-providing location and compare the approaches. Your attention to this matter has helped us improve this paper by providing a straightforward presentation of a proposed method for assessing geospatial ride-providing burden while acknowledging methodological limitations and providing suggestions for future investigation. Thanks. 

Comment 3: Requirement: The authors must separate the analysis. Do not mix SDE and RNB data in one model. Please present the analysis results for the SDE group (n=12) separately. If the sample size is too small to yield significance, then present it as descriptive data; do not force an incompatible correlation analysis.

Response 3: This comment is a recommendation for addressing the major concern in Comment 2: Please see Response 2 for how we handled your concern and recommendation. You can see our revisions in the narrative and tabular presentations of findings in the Results section, as well as some changes to the Discussion, including the added paragraph regarding future examination of using a road network buffer approach. 

Round 3

Reviewer 2 Report

Comments and Suggestions for Authors

The authors should not depend on AI to solve my problems. I am not satisfied with your answer. The conclusion is necessary. Furthermore, there also have problems not normal as follow.

1.How to coordinate the relationship of olders and ride provider in this manuscript?

2. In fact, there have many words illustrated the ride provider. Why the keywords only shown older adults?  The ride provider is not equal to caregiver.

3.There only have 5 points in figure 1. Using standard deviation ellipse have no significance.

Comments on the Quality of English Language

The English should be polished. There have several grammar errors.

Author Response

Overall Comment: The authors should not depend on AI to solve my problems. I am not satisfied with your answer. The conclusion is necessary. Furthermore, there also have problems not normal as follow.

Overall Response: As stated in our Round 2 response, we only used AI in addition to several native English speakers. We continue to refine the language, grammar, punctuation in each round of revision, but disagree that the manuscript does not use appropriate English. We are happy to continue making copy edits as needed. We have added a Conclusion section back to the manuscript. 

Detailed Comment 1: How to coordinate the relationship of olders and ride provider in this manuscript? 

Detailed Response 1: As mentioned in the methods and discussion sections, the survey research did not collect information about the relationship between the ride providers and the older person to whom they gave rides in private automobiles. This is an important line of inquiry in future research. 

Detailed Comment 2: In fact, there have many words illustrated the ride provider. Why the keywords only shown older adults?  The ride provider is not equal to caregiver.

Detailed Response 2: In earlier versions of the manuscript, we did not include either older adults or ride provider in the key words as both terms were in the title of the manuscript and therefore already amenable to online searches. We added the term older adult in response to your Round 2 request, which did not ask for us to also include the term ride providers.

Detailed Comment 3: There only have 5 points in figure 1. Using standard deviation ellipse have no significance.

Detailed Response 3: As described in the methods section and methodological literature cited in this manuscript, only 3 points are needed to construct a standard deviation ellipse. The example with 5 points is ample to create a SDE1. 

Reviewer 3 Report

Comments and Suggestions for Authors

1. General Evaluation

The authors have satisfactorily addressed the major concern raised in the previous round regarding the statistical validity of mixed data. By excluding the participants who did not meet the criteria for the Standard Deviational Ellipse (SDE) model (the RNB group) and restricting the analysis to the SDE group, the study now presents a more methodologically consistent analysis.

2. Specific Comments

Resolution of Statistical Issue: I acknowledge and appreciate the authors' decision to remove the incompatible RNB data. This ensures that the correlation analysis and descriptive statistics are derived from a geometrically homogeneous group. This directly addresses the concern about mixing "planar ellipse" and "linear buffer" data. Although the sample size has decreased, it does not affect the scientific validity of the study.

3. Recommendation

Accept (or Minor Revision at Editor's Discretion)

Comments for author File: Comments.pdf