Assessment of Greenhouse Gas Emissions from Heavy-Duty Trucking in a Non-Containerized Port through Simulation-Based Methods

Round 1

Reviewer 1 Report

Several figures in the document have low resolution or contain too small and unclear text to read, making them unsuitable for publication. These figures are requested to be corrected, and grids will be added wherever possible. Additionally, the overall quality and resolution of the images are below the expected level.

While it is acknowledged that estimating probability distributions from real data is a complex task, it often appears to be imprecise and arbitrary. It would be highly appreciated if you could better explain how this estimation was carried out.

The article appears to focus more on data processing, giving less attention to the simulation model. However, the simulation model is not less complex. Therefore, it would be helpful if you could explain the simulation model better.

Author Response

We greatly appreciate your thorough review of our manuscript and the valuable feedback you have provided. Your constructive comments and suggestions have been instrumental in enhancing the overall quality and clarity of our paper. We have diligently addressed each of your concerns and made the necessary revisions to our manuscript. Enclosed, please find the file containing the responses to your comments.

Author Response File: Author Response.pdf

Reviewer 2 Report

The current study proposes a simulation-based assessment method for GHG Emissions in a Non-Containerized Port. The presented topic is interesting and fits within the scope of the journal. Overall, the paper is written well, however, there are a few minor concerns and limitations which should be addressed prior to its acceptance. Consider the following points in this regard.

Point#1: The specific contribution and innovation point of study should be explicitly highlighted. Also, study motivations should be improved.

Point#2: Introduction and related studies sections should be expanded by including latest studies related to the topic. Examples: https://doi.org/10.3390/su141811577;  doi.org/10.3390/ijerph18115567

Point#3: Highlight the pros and cons of the proposed assessment methods compared to other contemporary techniques for GHG emission.

Point#4: The analysis is based on simulation techniques. Validation using real-life data would add value to the study.

Point#5: Lines 382-385, in addition to data collected on these parameters data on additional important parameters such as acceleration/deceleration, number of stops, and presence/absence of traffic control could have been included as these parameters are also important and influential factors (for GHG emissions).

Point#6: Formatting and resolution of Figures 9-19 should be improved.

Point#7: The type of distribution based used (Probability distributions adopted for modeling various parameters) was based on what criterion. Suitable references should be mentioned.

Point#8: GHG emission is widely influenced by the composition of the traffic spectrum. The specific proportion of various vehicle types considered should be highlighted.  

Point#9: Table, what is the unit of column (Global warming potential). These numbers reflect rank, percentages, etc.?

Point#10: All the variables used in the formulae should be defined. Providing a table of acronyms and defining variables would be more appropriate.  

Point#11: A dedicated discussion section should be included. This should contain an intuitive discussion based on the study results and critical analysis in light of previous studies.  

Point#12: A section emphasizing on the study’s usefulness for practical policy implications should be added.

Point#13: The conclusions section should be curtailed summarizing key findings and takeaways from the current study.  

Minor editing of English language required

Author Response

We greatly appreciate your thorough review of our manuscript and the valuable feedback you have provided. Your constructive comments and suggestions have been instrumental in enhancing the overall quality and clarity of our paper. We have diligently addressed each of your concerns and made the necessary revisions to our manuscript. Enclosed, please find the file containing the responses to your comments.

Author Response File: Author Response.pdf

Reviewer 3 Report

The submitted manuscript presents an analysis of the role of ports in greenhouse gas (GHG) emissions, with a focus on non-containerized ports. While the study is well structured, there are several areas that could be improved upon to enhance the quality and clarity of the work.

(1) Naming conventions and consistency:

There are inconsistencies in the use of acronyms throughout the manuscript. For example, on line 71 "...and DPM" the reader is not initially informed of what DPM stands for. This lack of initial definition makes it difficult to understand the context. It is important to provide a full definition of acronyms the first time they are used and to maintain consistency throughout the text.

(2) Long sections and brevity:

The Literature Review and Methodology sections could benefit from brevity. The Literature Review is lengthy and includes detailed discussions of individual studies that may not be directly relevant to the current investigation. Streamlining the section to focus on the relevant literature and highlighting the most relevant findings would improve the readability and conciseness of the paper. Similarly, the Methodology section contains detailed descriptions of basic data processing that could be better presented in supplementary materials or figures.

(3) Choice of GHG emission model:

The choice of emission model to calculate GHG emissions is not clearly justified. The manuscript cites using "the method used by the San Pedro Bay ports of Long Beach and Los Angeles" but does not provide a clear rationale for why this approach was selected over more established models such as COPERT or MOVES. It is important to clarify the rationale for the selection of this method and its comparability or advantages over other established models. Additionally, Table 4 shows a single emission factor for each speed interval across all vehicle types. It's important to clarify whether these emission factors are applicable to all vehicle types or whether they are specific to certain types, as this could affect the emission calculations and their accuracy. In further, as described by the authors, the unit of vertical coordinate of Figure 22 should be g/mile.

(4) Grammar, spelling and punctuation:

The manuscript contains several grammatical and spelling errors that detract from its professionalism and readability. These include errors such as "prebviously" (line 446) and inconsistencies in punctuation usage, such as the lack of a comma before "and Microscopic models" in line 97. These errors should be corrected to improve the overall quality of the manuscript.

In summary, the manuscript provides an interesting examination of the role of ports in GHG emissions, but could benefit from improvements in several areas, including consistency in naming conventions, brevity in certain sections, and clarification regarding the choice of emission model. With these recommended changes and improvements, the manuscript would be well positioned for publication.

Author Response

We greatly appreciate your thorough review of our manuscript and the valuable feedback you have provided. Your constructive comments and suggestions have been instrumental in enhancing the overall quality and clarity of our paper. We have diligently addressed each of your concerns and made the necessary revisions to our manuscript. Enclosed, please find the file containing the responses to your comments.

Author Response File: Author Response.pdf