Road rage exists in many forms, from mild to very extreme. Besides the psychological trauma and possible injury, indirect effects are speeding, ignoring road signs, poor lane discipline and lack of courtesy. Road rage may also be costly in terms of higher fuel consumption, tyre and brake wear and the repair of collision damage. A Scottish study found that one quarter of drivers had given chase to others who had offended them in some way, while eight per cent had actually had a fight with other motorists. The British Automobile Association reports that nine per cent of drivers were victims of either verbal or physical attack last year.
American surveys suggest that young male drivers dominate road rage.
The Australian Associated Motor Insurers crash index shows aggressive driving as the cause of an increasing rate of rear-end collisions and incidents due to failure to give way. This is despite a general fall in the road toll, improved driver training and better roads. While such events may not directly represent road rage, they do suggest related factors. Pedestrians and cyclists are not excluded from road rage. Harassment can be directed at them by aggressive motorists or their passengers.