Driving at excessive or inappropriate speed is a major threat to safety on the road. It is estimated that 10 to 15% of all crashes and 30% of all fatal crashes are the direct result of speeding or inappropriate speed. The faster someone is driving, the higher the risk of a crash, but also the higher the severity of the crash and the probability that the crash is fatal. Another important factor influencing the crash risk are differences in vehicle speed. The less the speeds of vehicles differ from each other, the lower the risk of a crash. The main factors affecting the impact of speed-related crashes are: the design of the road, the safety systems in vehicles, differences in mass between the colliding vehicles/ road users, and the vulnerability of the road users. The probability that a vulnerable road user (pedestrian, cyclist, motorcyclist) will die in a collision with a passenger car or truck is much higher than that for the occupants of a vehicle. This is one of the main ar-guments in favour of the introduction of low speed zones in densely populated areas. Speed limits are frequently exceeded by many car drivers. 67% of Europeans admit to having speeded on rural roads over the previous 30 days. There are five main reasons why people drive too fast: (1) matching the speed of surrounding traffic; (2) being in a hurry; (3) enjoying driving fast; (4) out of boredom; and (5) being unaware of driving too fast. Speeding is socially more accepted than other traffic code violations such as drunk driving. Measures against (excessive) speed are possible and necessary in several areas: • determination of appropriate speed limits; • adequate design of road infrastructure; • enforcement of speed limits; • education and awareness • vehicle technology. Structural improvement of speeding behaviour requires a combination of measures. Speed limits should be based on the principle of injury minimization. They will depend on the traffic situation, such as the interactions and possible conflicts between different road users, and on the design of the roads (e.g. curvature of the road, presence of a me-dian barrier). Speed limits should be credible for drivers – not perceived as too low or too high – and infrastructural characteristics (e.g. curvature, width, presence of hard shoulder) should reinforce this credibility, otherwise speed limits will not be observed. Enforcement of speed limits by speed detection systems has been shown to be effective in reducing crash and injury risks, in particular section control systems. Speeding can also be prevented by education of young people and by awareness campaigns, in partic-ular when combined with other measures. Safety systems in cars (such as intelligent speed assistance systems) can prevent people from speeding or reduce the severity of a crash. (Author/publisher)
Abstract