Serial Mediation Effects of Driver Fatigue and Cognitive Impairment on the Relationship Between Occupational Stressors and Wellbeing Among Commercial Truck Drivers: A PLS-SEM Analysis

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

The manuscript presents a well-structured investigation into the complex relationship between occupational stress and well-being among Thai truck drivers, with a focus on sequential mediating mechanisms. The study addresses a relevant topic with practical implications for occupational health and sustainable transportation systems. The use of PLS-SEM to analyze the proposed model is appropriate, and the findings contribute to understanding the interplay among multiple stressors. However, several issues need clarification or improvement before acceptance.

1. Does the sample in the paper adequately represent the truck driver population in Thailand? This should be described in conjunction with the statistical distribution characteristics of truck drivers in Thailand. If representativeness is insufficient, this must be clearly articulated in the limitations section.
2. The data were collected between January and April 2025. Still, the study does not discuss whether this period coincided with unique contextual factors in Thailand (e.g., seasonal logistics demand, economic policy changes, or extreme weather events) that may have influenced driver stress or well-being.
3. The finding that logistics infrastructure has no direct effect on well-being but acts as a full sequential mediator is intriguing. The authors should clarify how this aligns with prior literature and whether it reflects unique characteristics of the Thai trucking industry.

Comments on the Quality of English Language

The English in the manuscript is functional but flawed. The core meaning is generally understandable, but frequent grammatical errors, non-idiomatic expressions, and inconsistent terminology mar the text. It has not yet been polished to the standard expected for publication in an international journal. A thorough revision focusing on clarity, conciseness, and grammatical accuracy is essential.

• Articles (a, an, the): Missing articles are a pervasive issue.
• Original: "This gap... creates major problem in transportation research."
• Revision: "This gap... creates a major problem in transportation research."
• Original: "Thailand is now major logistics center..."
• Revision: "Thailand is now a major logistics center..."
• Subject-Verb Agreement:
  • Original: "...work stress, financial stress, and environmental stress constitutes antecedent factor..."
  • Revision: "...work stress, financial stress, and environmental stress constitute antecedent factors..." (Plural subject requires a plural verb and noun).
• Prepositions:
  • Original: "Data were collected... through voluntary participation in an online survey utilizing a validated 5-point Likert scale instrument..."
  • Revision: "Data were collected... via a voluntary online survey using a validated 5-point Likert scale instrument..." ("Via" or "through" is more concise than "through participation in"; "using" is simpler than "utilizing").
• Spelling and Typos:
• • Original: "...deteriorating withing two hours..."
  • Revision: "...deteriorating within two hours..."

Author Response

1. Does the sample in the paper adequately represent the truck driver population in Thailand? This should be described in conjunction with the statistical distribution characteristics of truck drivers in Thailand. If representativeness is insufficient, this must be clearly articulated in the limitations section.
   
   Thank you for this important question regarding sample representativeness.  The sample of 534 truck drivers demonstrates characteristics consistent with available industry data: 95.3% male aligns with Thailand's male dominated trucking industry, 67.6% with over 10 years experience indicates seasoned professionals, 77% driving semi-trailers represents the dominant vehicle type in freight transport, and 86.5% permanent employment matches typical industry employment patterns.  In accordance with the Ministry of Transport of Thailand had around 1.2 million registered truck drivers as of February 2024, though comprehensive demographic breakdowns in public databases are limited.  We acknowledge several representativeness limitations; our online survey method may have excluded older drivers or those with limited digital access, voluntary participation introduces self selection bias, regional distribution was not specifically controlled, and freelance or contract drivers may be underrepresented compared to actual industry proportions.  We will add this discussion to the limitations section, explicitly stating that while our sample demonstrates consistency with known industry characteristics regarding gender distribution, employment type, and vehicle categories, the convenience sampling approach and online data collection method limit full representativeness of Thailand's diverse truck driver population, and future research should employ stratified sampling across regions, employment types, and demographic categories to enhance generalizability.
   
   
2. The data were collected between January and April 2025. Still, the study does not discuss whether this period coincided with unique contextual factors in Thailand (e.g., seasonal logistics demand, economic policy changes, or extreme weather events) that may have influenced driver stress or well-being.
   
   Thank you for pointing.  The January to April 2025 data collection period coincided with several contextual factors in Thailand that may have influenced our findings.  Firstly, January and February typically experience increased freight demand following year-end holiday season, potentially elevating work stress and fatigue levels among drivers beyond typical conditions.  Secondly, March and April mark the beginning of Thailand's hot season with temperatures, which could have amplified environmental stress responses in our data, particularly for the 55.1% of drivers operating shorter routes with frequent loading and unloading exposure to extreme heat.  Thirdly, Thailand's economic conditions in early 2025, including any regional supply chain adjustments, may have intensified delivery pressures contributing to financial stress patterns observed in the findings.  These contextual factors may have influenced absolute stress and fatigue levels reported, with environmental stress impacts potentially elevated due to hot season conditions and work stress possibly reflecting seasonal demand peaks.  However, we will add this discussion to the limitation section, noting that the data collection during this specific period may influence absolute stress levels.  As well, the future longitudinal research across multiple seasons would strengthen understanding of variations.
   
   
   
3. The finding that logistics infrastructure has no direct effect on well-being but acts as a full sequential mediator is intriguing. The authors should clarify how this aligns with prior literature and whether it reflects unique characteristics of the Thai trucking industry.
   
   Thank you for raising this point.  Our finding shows that logistics infrastructure had no direct effect on wellbeing but significant total effects through serial mediation via fatigue, cognitive impairment, and accident risk.  This pattern actually fits well with occupational health research showing infrastructure quality works through physical mechanisms rather than psychological ones.  Unlike financial stress, which drivers consciously recognize as threatening, infrastructure quality depletes resources gradually through physical strain (vibration, posture adjustments, sustained attention) without triggering direct psychological distress.  This makes sense in Thailand's context where experienced drivers (68.4% with over 10 years) have psychologically adapted to existing road conditions but still face physical toll through fatigue accumulation.  However, we will expand our discussion section to highlight these theoretical insights and practical applications.  
   
   concerning the English in manuscript, we would use the service of MDPI.  
   
   Thank you very much.

Reviewer 2 Report

Comments and Suggestions for Authors

The paper entitled "Serial Mediation Effects of Driver Fatigue and Cognitive Impairment on the Relationship between Occupational Stressors and Wellbeing among Commercial Truck Drivers: A PLS-SEM Analysis" has an important and current topic, is methodologically well defined and well structured. The authors clearly explain the theoretical framework, the justification of the research and the complex model with 18 hypotheses. The sample of over 500 is representative, the statistical analysis is correctly performed, and the presentation of the results is clear. However, the text is too long, there is a lot of repetition, and some parts require a stronger focus on practical implications and limitations. Some terms and wording are unclear, so I recommend a minor revision before publication.

Pages 1–3 often repeat the same arguments (stress, fatigue, importance of drivers for logistics). The introduction should be shortened by about 20–30%, and the focus on the shortcomings of previous studies (eg, little research on serial mediation) should be strengthened, as well as what is new in this paper should be better highlighted (novelty is mentioned, but not explicitly emphasized). The review of the literature is in a similar spirit. To further improve the literature review, reviewers can consider papers that introduce the pyramidal concept of functional ranking of scientific contributions, such as the modern Pyramid of Contribution Review. That way, you would clearly show the gap and emphasize the novelty of your work. Also, include a couple of more recent works in the literature review and address this issue as well. Previous studies show that the perception of warning signs and hazard markings varies significantly across demographic groups (https://doi.org/10.56578/judm030105), suggesting that visual information processing plays a critical role in traffic safety. This supports the relevance of cognitive functioning as a mediating factor in driver behavior.

Methodology goes under the new number 3, as a separate entity, certainly within section 2. Be sure to pre-set the chapter titles.

The results are nicely presented, however, it is interesting to me and I ask that it be explained more clearly, why infrastructure does not have a direct effect, although it would be expected to have, as well as a negative sign (β = -0.263), so this interesting result should be interpreted much more clearly.

I believe it's a big job, but I'm sure some of the reviewers will ask you to separate the discussion from the conclusion. If none of the other reviewers mention it, they don't have to because of me, this is a non-binding suggestion.

The paper mentions "Thailand specific patterns", but does not give systematic limitations. It is necessary to add that the sample is only from Thailand, that self-report was used, the risk of socially desirable answers, cross-sectional design, possible variances due to different types of routes, companies and payments.

Recommendations for future research are not sufficiently structured, so suggest: longitudinal studies, experimental measurements of fatigue (eg EEG, simulations), comparison of different regions (rural/urban, north/south) and similar.

Check the English language, e.g. "Driver exhausting" instead of "Driver exhaustion".

All in all, the paper is very innovative, clear and represents valuable scientific research.

Comments on the Quality of English Language

Check the English language, e.g. "Driver exhausting" instead of "Driver exhaustion".

Author Response

I do thank you for pointing out several key issues.  Kindly see the attachment.

Author Response File: Author Response.pdf