Microscopic Analysis of Traffic Flow in Inclement Weather Conditions

Inclement weather is one of the key causes of congestion because drivers typically attempt to drive at lower speeds with increased caution. Additionally, inclement weather contributes to more than 1.5 million crashes every year. Several studies have quantified the effect of inclement weather on macroscopic traffic stream behavior, including its impact on the roadway capacity and speed. However, it is hard to find studies that characterize individual driver behavior under adverse weather conditions and that analyze the variability in driver behavior.

Furthermore, it is difficult to find studies that specifically assess the impact of icy pavement conditions on driver behavior. The objective of this study is to quantify the impacts of icy roadway conditions on driver behavior at a microscopic level, using field-measured car-following data, in addition to the study of the typical variability in driver behavior. In addition the study quantifies the impact of rain and snow on driver gap acceptance behavior and finally develops procedures to incorporate inclement weather effects in a microscopic traffic modeling environment.