Professor Michael Zhang, Department of Civil and Environmental Engineering, UC Davis
Saturday April 29, 2023
1:50 pm - 2:25 pm
Should California increase the speed limits of its highways?
Abstract
This work estimates the safety and mobility impact of changing speed limits on California highways. The safety impact is estimated using statistical models to predict the change in the frequency of all crashes and fatal-or-severe crashes that would result by varying the speed limits. The operational condition (speed, travel time, delay) is tested using seven simulation segments with urban-rural classification. The results show a decrease of travel time but an increase of fuel consumption as the speed limits get higher. The safety cost of crashes and operational costs were also estimated based on the simulation models. In general, as the speed limits are increased, the safety costs increase with the predicted increases in crashes, particularly severe and fatal crashes. The operational costs, on the other hand, generally decrease as the speed limits are increased. From the economic perspective in this study, raising speed limits on rural California highways could reduce monetary costs, as savings in operational costs would exceed losses from more crashes.