This study determines the index numbers for lorries on three types of Dutch (state) roads: motorways, trunk roads and roads marked as forbidden to slow traffic. The following index numbers are provided for road stretches and road sections: (1) The total number of accidents (injury, and material damage only) for each vehicle kilometre travelled; and (2) the number of injury accidents for each vehicle kilometre travelled. The index numbers were determined by dividing the number of accidents in the numerator by the vehicle kilometres in the denominator. In the study, only the distribution of the numbers of accidents in the numerator was determined. On motorways with two traffic lanes in each direction, the risk levels for lorries and light vehicles (passenger cars and vans) are not substantially different. On motorways with three and four traffic lanes in each direction, however, the risk level for lorries is higher than that for light vehicles. The risk level for both vehicle types and for injury accidents and accidents involving material damage only is higher on motorways with three and four traffic lanes in each direction than on motorways with two traffic lanes in each direction. (A)
Abstract