Analysis of Uncertainty Associated with Response Time in Work Zone Traffic Accidents

Considering the uncertainty of response time to work zone traffic accidents, the response time is assumed to be a random variable following a lognormal distribution. The lognormal distributed response time is further modeled via a mixed linear regression function of factors including road type, day of the week, occurrence of a holiday, light condition, work zone type, crash time, and weather. The Bayesian approach is used to calibrate the lognormal distribution model. A case study was created using work zone traffic accident data from the Fatality Analysis Report System between 2002 and 2009. The results showed that the uncertainty of the response time was primarily influenced by road type, crash time, weather, and light conditions. In order to shorten response times, it is suggested that work zone activities are to be undertaken during non-holidays, during the daytime, and in good weather and light conditions.