Identification of Factors Leading to High Severity of Crashes in Rural Areas Using Ordered Probit Modeling

This study made an effort to identify critical factors contributing to increased crash severities on rural highways. Crash data from the Kansas Accident Reporting System (KARS) database was analyzed and crash severity was modeled using ordered choice models. Many driver-related factors, such as alcohol involvement, lack of seat belt usage, excessive speed, and driver ejections because of the crash contribute to the increased severity of crashes in rural areas. Also, severities of singlevehicle crashes are higher than two-vehicle and animal-vehicle crashes. Factors related to roadway geometry such as sharp curves and steep grades are also found to contribute to the increased crash severity in rural areas.