A traffic collision, also known as a traffic accident, motor vehicle collision, motor vehicle accident, car accident, automobile accident, Road Traffic Collision (RTC) or car crash, occurs when a vehicle collides with another vehicle, pedestrian, animal, road debris, or other stationary obstruction, such as a tree or utility pole. Traffic collisions may result in injury, death and property damage.
A number of factors contribute to the risk of collision including; vehicle design, speed of operation, road design, road environment, driver skill and/or impairment and driver behaviour. Worldwide motor vehicle collisions lead to death and disability as well as financial costs to both society and the individuals involved.

http://en.wikipedia.org/wiki/Traffic_collision