Pedestrian Crosswalk Safety at Nonsignalized Crossings During Nighttime: Use of Thermal Video Data and Surrogate Safety Measures
Bibliographic record
Abstract
This paper proposes a methodology to evaluate crosswalk pedestrian safety at nighttime by using surrogate safety measures derived from thermal video data. The methodology is illustrated for two unsignalized crosswalk locations in downtown Montreal, Quebec, Canada. Video recordings from a thermal camera were used to compare nighttime and daytime safety conditions with surrogate safety measures that included vehicle approaching speed, postencroachment time (PET), yielding compliances, and conflict rates. A disaggregate measure of pedestrian exposure that excludes noninteracting road users is also proposed. A thermal camera was used to alleviate issues pertaining to low visibility at night for video analysis when road users, especially pedestrians, are difficult to track. The results showed that the thermal-video–based methodology could effectively collect interaction data at night regardless of lighting conditions. Through the use of thermal video data and the methodology proposed in this paper, the interactions between crossing pedestrians and motor vehicles, with related measures such as PET and speed, could be analyzed to evaluate the effect of different crosswalk treatments on pedestrian safety in low-visibility conditions.
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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 | 0.005 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.000 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.001 | 0.001 |
| Scholarly communication | 0.000 | 0.001 |
| Open science | 0.001 | 0.000 |
| Research integrity | 0.000 | 0.001 |
| 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".