Abstract
The 1999 statistics from the Fatality Analysis Reporting System (FARS) showed that nearly 39 percent of the 37,043 fatal crashes were single-vehicle Run-Off-Road (ROR) crashes on various road types. Crash data statistics display the vulnerable roadway systems to ROR crashes that should be targeted for appropriate countermeasures. The purpose of this project is to provide insight into the reasons behind ROR collisions, and how the ROR project is initiated by the California Department of Transportation (Caltrans). Countermeasures, such as horizontal curve improvement, stabilized and widened shoulders, and flattened sideslopes are methods essential in reducing ROR collisions. The plan also determines the estimated cost-effectiveness when the safety measures are implemented. In this study, the results showed that 55 percent of ROR collisions happened within a 5-year period of data retrieval. A hundred percent of single-vehicle incidents were related to ROR collisions. Twenty percent of ROR collisions occurred on wet pavement surfaces, while eighty percent were under dry conditions. Fifty percent of the ROR data obtained included fatal collisions.