Activity-Based CO₂ Emission Analysis of Rail Container Transport: Lat Krabang Inland Container Depot–Laemchabang Port Corridor Route

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

This manuscript addresses an important topic by analyzing CO₂ emissions differences between rail and road container transport along Thailand’s critical Lat Krabang–Laem Chabang corridor. The use of an activity-based methodology and empirical fuel consumption tests strengthens the practical relevance of the work. The results offer useful insights for low-carbon transport policy in developing countries. However, the paper suffers from weaknesses in methodological transparency, literature organization, figure presentation, academic writing, and data clarity. Substantial revisions are needed before the manuscript can be considered for publication.

1. The abstract should be shortened to under 250 words, focusing on the research problem, main methods, results, and conclusions. Excessive technical detail can be moved to the methods section.
2. Consider revising the title to include the methodological approach, such as "Activity-Based CO₂ Emissions Analysis…" to better reflect the core contribution.
3. The literature review (Sections 2.1–2.4) is overly repetitive and unfocused. It is recommended to condense it into 2–3 concise thematic paragraphs with a clear emphasis on the research gap.
4. Figure 3 lacks a clear flow structure. Use arrows, process blocks, or stepwise labels to better illustrate the methodological process.
5. The system boundary of the analysis is not clearly defined. It should be explicitly stated whether terminal handling emissions (e.g., port operations) are included.
6. The paper lacks detail on equipment calibration and error control in the fuel consumption testing phase. Clarifying these procedures would improve the credibility of the empirical data.
7. The sample size for certain data sources (e.g., reach stacker operations) appears too limited. Broader sampling or justification of representativeness is recommended.
8. Tables and results should include error bars, standard errors, or confidence intervals to allow for assessment of statistical significance.
9. The regression analysis linking train weight to fuel consumption should include confidence intervals, R² values, and p-values to demonstrate the reliability of the model.
10. Several figures lack labeled axes or units. All charts and graphs should include complete axis labels and measurement units.
11. Mathematical formulas and equations should be properly numbered and typeset. Consider using LaTeX or similar formatting for consistency and readability.
12. The discussion section should be better structured into subthemes—for example: interpretation of results, comparison with existing literature, and implications for policy.
13. The selection and application of emission factors lack robustness. Consider conducting a sensitivity analysis or triangulating with multiple data sources.
14. The policy implications should be grounded more explicitly in Thailand's current transportation and logistics strategies.
15. There is significant redundancy in the use of certain phrases, such as "significant difference in emissions." Language should be streamlined and repetitive phrases reduced.

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

This study on the CO₂ emissions associated with rail container transport in Thailand, specifically along the Lat Krabang Inland Container Depot to Laem Chabang Port corridor, holds practical significance in addressing the carbon emissions issue in Thailand's railway container transport process. However, there are major issues that need to be addressed and revised.

1. The author provides a detailed introduction to the research background, analyzing the unique characteristics of the Thai region to fill the research gap in the comparison of emissions between rail and road transport in Southeast Asian countries. The author also mentions that while extensive research has been conducted on freight emissions in Europe and North America, there is a lack of specific descriptions of freight emissions in these studies, particularly regarding the methods used and their limitations. How does the author's approach compare to these studies in terms of advantages and innovation?
2. The literature review section is quite detailed, but what confuses me is that while the author organizes and summarizes a large number of studies, such as in Section 2.2, there is no clear discussion on the advantages and innovations of the author's proposed method in comparison to previous research. It only briefly mentions adapting to the context of Thailand's container transport industry. In simple terms, the author merely lists the existing studies in the literature review without providing a critical comparison to their own method.
3. The limitations of selecting emission factors are that locomotive emission factors based on manufacturer specifications and operational test data may not fully reflect all real-world operating conditions. Although local adjustments have been made to the emission factors, it is uncertain whether these adjustments are precise enough to cover all environmental variables. For example, certain areas may have unique weather, traffic conditions, or other factors that can affect emissions but were not fully accounted for.
4. How are the emission factors determined? Are there any references or supporting literature? Based on experience, is the approach reasonable? Is there any basis for the principle and formula of the Calculation Model for Carbon Emissions? Is there any subjectivity involved?
5. The article mentions adjusting locomotive emission factors using a fuel consumption equation to account for changes in train weight. However, does this empirical adjustment consider the nonlinear emission patterns of trains under different loads? Different types of cargo, train speeds, and track gradients can all lead to deviations between the emission factors and the standard emission factor.
6. The article uses a power relationship model to describe the relationship between train weight and fuel consumption. Has the applicability of this model been considered for different train types or cargo types? Are there other factors, such as temperature and humidity, that significantly affect fuel consumption?
7. In result, the article states that rail transport has a 38.23% advantage in terms of carbon emissions. What is the core reason for this advantage? Besides the increased load, have other factors been considered in evaluating their impact on energy efficiency?
8. The carbon emissions of road transport are significantly higher than those of rail transport. Is this difference solely due to the flexibility of road transport and shorter times, or are there other contributing factors? Are there specific strategies in place that could help reduce emissions from road transport?
9. Terminal operations, such as container handling and loading, contribute 36% to the emissions from rail transport. Is there potential for technological upgrades or optimization in these operations? Please add discussion.
10. The author proposes a large number of policy recommendations for short, medium, and long-term periods. How are these conclusions and recommendations derived from the experimental results? Additionally, how are the different periods defined? There is some confusion, and further explanation is needed.

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

Accept in present form

Reviewer 2 Report

Comments and Suggestions for Authors

The authors have properly addressed the comments and have largely improved the quality of the manuscript. I recommend the paper for publication.