Aggressive driving is a major factor in U.S. traffic accidents, playing a role not just in well-publicized incidents of road rage, but in a large number of fatal highway collisions each year. The National Highway Traffic Safety Administration (NTHSA) defines aggressive driving as occurring when "an individual commits a combination of moving traffic offenses so as to endanger other persons or property." While aggressive driving is difficult to quantify, a 2009 study by the American Automobile Association attempted to identify behaviors associated with aggressive driving, based on data tracked by NHTSA’s Fatal Accident Report System (FARS). It found that aggressive driving played a role in 56 percent of fatal crashes from 2003 through 2007, with excessive speed being the number one factor. The following driver-related contributing factors in FARS were taken as indications that crashes may have involved aggressive driving:
Speeding was the leading driving behavior associated with fatal crashes in 2014. Speeding was a factor for 18.8 percent of drivers and motorcyclists who were involved in fatal crashes, followed by driving under the influence (12.3 percent), according to an analysis by NHTSA. Distracted driving was a factor for 6.7 percent of drivers and motorcyclists who were involved in fatal crashes. (Note: NHTSA provide guides, planners and information to law enforcement professionals and prosecutors to assist in the reduction of aggressive driving on its website).