Freeway Crash Timeline Characteristics and Uses

Document Type




Publication Date



National Academy of Sciences

Source Publication

Transportation Research Record

Source ISSN



Timeline information for freeway crashes was extracted using 10,589 crashes, 2,816 of which were matched with enforcement agency dispatch records and 320 of which were matched with ambulance dispatch records. The average time between when a crash occurred and when the crash scene was cleared was 52.2 min. The enforcement agency was notified 3.4 min after the crash, and the first responding officer arrived at the crash scene 6.0 min later. The ambulance dispatcher was notified 5.1 min after the first responding officer arrived at the scene, and the first ambulance arrived at the scene 7.5 min later, remained at the scene 20.9 min, and arrived at the hospital 10.9 min after it left the crash scene. Enforcement agency notification and response times were not affected by crash and environmental factors; however, enforcement agency on-scene time (representing 80 percent of crash duration) was statistically related to crash type, crash severity, need for emergency medical services transport, air bag deployment, light condition, manner of collision, road condition (presence of precipitation), number of injuries, number of involved vehicles, need for towing services, and extent of vehicle damage. The shortest crash durations were associated with two-vehicle crashes, crashes involving property damage only, and crashes involving vehicles able to drive away. The longest crash durations were those involving very severe vehicle damage, occupant medical transport, an overturned vehicle, and those occurring at night.


Transportation Research Record, No. 1748 (2001): 132-143. DOI.