Safety

The report summarizes the findings from comparative studies of safety performance between two different types of High Occupancy Vehicle (HOV) facilities in California - continuous access versus limited access. The findings show that HOV facilities with limited access offer no safety advantages over those with continuous access, whether measured by percentage of collisions, collisions per mile, collisions per VMT, or collision severity. As part of the present research, the authors investigated the relationship between HOV design features and safety performance of HOV facilities. One key...

Linear and nonlinear multivariate statistical analyses are applied to determine how the types of accidents that occur on heavily used freeways in Southern California are related both to the flow of traffic and to weather and ambient lighting conditions. Traffic flow is measured in terms of time series of 30-second observations from inductive loop detectors in the vicinity of the accident prior to the time of its occurrence. Results indicate that the type of collision is strongly related to median traffic speed and to temporal variations in speed in the left and interior lanes. Hit-object...

California is home to major international ports in Long Beach, Los Angeles, and Oakland, as well as the second largest border crossing between Mexico and the U.S. California’s highways are critical commercial links from these ports of entry to the nation and carry more commercial vehicle truck traffic than any other state in the U.S. Given the high volume of truck travel in California, it is not surprising that there is a serious shortage of truck parking in the state. This shortage negatively impacts economic productivity, roadway safety, air quality, and public health. This report begins...