Pedestrian Crosswalk Safety at Nonsignalized Crossings During Nighttime: Use of Thermal Video Data and Surrogate Safety Measures

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.