Abstract

Roadway artificial lighting assists drivers to navigate to their final destination at night time. Despite less traffic during such period of time, most fatal accidents occur at dark conditions. Factors such as fatigue, impaired driving, poor visibility and excessive speed contribute to make driving during night more dangerous than any other time of day. The impact of weather conditions on lighting to explain road collisions has not been investigated in the literature. This thesis explores weather at the time of road collisions during nighttime for accidents observed at Victoria Ville in Quebec. Available data encompassed various characteristics including values of illuminance measured during 2014 for the entire network in one night. Values of various lighting parameters were measured again at different weather conditions and attached to the database. Two analyses were conducted: One with the change in lighting conditions for roads in the region and the other without making any changes to understand the impact of weather on visibility issues leading to collisions. Two methods of representation of collisions and various road segment sizes were tested.

The results show that the recommended approach is to consider weather dependent illuminance, luminance and Unified Glare Index values for each individual collision. If the analysis is based on collisions frequency, then 100 meter segments are recommended, if the analysis is based on collisions severity, then 500 meters segments are advisable.