Some academic researchers believe there is a growing trend of simple aggressive behavior where a driver reacts angrily to other drivers, i.e., honking, tailgating, gesturing and cutting them off. In the Washington, D.C., metropolitan area, aggressive driving has reached such epidemic proportions that motorists rank it ahead of drunk driving among their concerns. However, attention has only recently been focused on aggressive driving as a national problem. As with most behaviors, it arises from a culmination of overlapping factors. While some personality types may have a propensity for aggressive driving behaviors, given the right circumstances anyone can fall victim.
Congestion is a leading cause of aggressive driving.
In the past decade, the number of cars has grown faster than the population. Very slow or stationary traffic situations present conditions which may trigger driver aggression. Some of the worst cases of aggressive driving have occurred where the opportunity for vehicles to separate and go their own way does not present itself. Some researchers also contend that traffic induced aggression stems in part from territorial defensiveness. The car is often considered an extension of personal space.