In connection with various proposals for a change in the speed limit system, the question has been raised of whether or not the 70 km/h speed limit for the group of vehicles concerned should be increased to 80 km/h. This would lead to a smaller difference in speed between different types of vehicles on roads with a speed limit higher than 70 km/h. Smaller speed difference between vehicles results in less overtakings thereby fewer results in overtaking accidents. Higher speeds however will increase the risk for other types of accidents. Using the VTI's traffic simulation model, changes in traffic effects, such as increased speeds of heavy vehicles and reduced overtaking frequency, have been studied and quantified. studied and quantified. The results of the simulations were used in a special accident model describing the relation between speed and accident rate and relation between speed and injury consequence. Studies have also been done with the introduction of a so called speed limiter fore heavy vehicles. Two levels of absolute miximum speed of a speed limiter were studied, 85 km/h and 93 km/h. The final EC proposal about speed limiters, implies that heavy lorries shall be equipped with speed limiters, preventing them from exceeding 90 km/h. (A)
Abstract