Modeling and spatial analysis of heavy-duty truck CO2 using travel activities
Bibliographic record
Abstract
Heavy-duty trucks (HDTs) are vital components of the freight industry yet have faced criticism for their substantial CO 2 emissions. This study, focusing on Xi'an, a crucial freight hub city in China, aims to investigate the factors influencing CO 2 emission from HDTs. A unique aspect of this study is using a Latent Dirichlet Allocation (LDA) model to evaluate the potential impact of different travel activities on CO 2 emissions using travel activities of HDTs extracted from extensive GPS data. Subsequently, the Random Forest (RF) model with a GeoShapley explainer was used to examine both the main and spatial effects of travel activities, road density, land use, and freight hub accessibility on CO 2 emissions. The results revealed the existence of fifteen distinct travel activities among HDTs in Xi'an, eight of which clearly influence CO 2 emissions. Considerable variations were observed in the magnitudes of the impact of different variables on CO 2 emissions, as indicated by GeoShapley values. The density of expressways and main roads has the greatest impact on CO 2 emissions, while various types of travel activities also significantly affect CO 2 emissions, with the impact of different travel activities varying to some extent. Additionally, there is evident spatial heterogeneity in the impact of various variables on CO 2 emissions, with larger positive GeoShapley values tending to concentrate around the 3rd Ring and expressways in Xi'an City. These findings, shedding light on the complex interplay of factors influencing CO 2 emissions from HDTs, provide valuable insights for formulating environmentally sustainable management policies concerning HDTs from spatial perspectives.
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.000 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one teacher head, not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".