Run-off-road (ROR) crashes, which usually involve only a single vehicle, contribute to a large portion of fatalities and serious injuries to motor vehicle occupants. In this study, the National Motor Vehicle Crash Causation Survey (NMVCCS) data collected at crash scenes between 2005 and 2007 is used to identify the ROR critical pre-crash event, assess the critical reason for the ROR critical event, and examine associated factors present in the pre-crash phase of the ROR crash. The effect of antilock brake system (ABS) and electronic stability control (ESC) on ROR crashes is also evaluated.