Collision Factor: Road Features and Conditions

Many of the most serious accidents (fatalities and disabling injuries) are associated with issues concerning the roadway.  Some of the commonly tracked categories include:

Left the Roadway

• Collision with a fixed object (perhaps a utility pole or tree)
• Vehicle overturn (perhaps an issue of roadway geometry or unprotected adjoining embankments and so forth)

Hit at Angle

• Entering the roadway at an angle (perhaps an issue of ramp or intersection configuration or of uncontrolled access from a driveway or parking lot)

 Going Same Direction

• Rear end collision (perhaps an issue of sight distance, inadequate channelization for turning or related issue)

 Going Opposite Directions

•  Head on collision (crossing the centerline)

These categories can apply to many different situations and not all accidents tallied in each category could be said to be associated with inadequacies of the roadway.  Nevertheless, the overall scale of such circumstances in the total picture of fatal and disabling accidents, as well as the significance of the categories in relation to each other, is important.

Roadway Circumstances and Conditions Associated
with Fatal and Disabling Injury Collisions

Washington State: 2002

There is significant inconsistency from circumstance to circumstance in the division between urban and rural aspects of the problem.  “Leaving the roadway” and “head-on collision” crashes are more likely to happen in rural areas than urban.  The opposite is true for “hit at angle” or “rear-end” crashes.  Accidents involving pedestrians and bicyclists are more likely in urban areas.

Source: WSDOT Transportation Data Office
Source Data: Roadway Circumstances and Conditions Associated with Collisions