DEVELOPMENTS IN ROAD SAFETY ACCORDING TO ROAD TYPE. ESTIMATION OF THE INDICATORS FROM 1978 UP TO 1993 INCLUSIVE FOR THE BENEFIT OF THE DUTCH MULTI YEAR PROGRAMME ON TRAFFIC SAFETY (MPV-4)

This study describes the traffic risk development on the Dutch road network from 1978 up to 1993 inclusive. A distinction is made, according to the road maintenance authority: national roads; provincial roads; the remaining roads outside built-up areas; and roads inside built-up areas. In addition, the traffic risk development is given for the various road types: motorways; secondary roads; roads closed to slow traffic; roads for all traffic outside built-up areas; and road types inside built-up areas, namely: arterial roads, residential streets, and the 'woonerf' streets. The risks are expressed in terms of injury accidents and road accident victims per million motor vehicle kilometres travelled. The results show that the risk figures for each of the road types differ markedly, both in magnitude and in their development in recent years. Possible explanations for the noted risk variations are sought partly in the relationship between the number of accidents and the average daily motor vehicle intensities per road type.These intensities are derived from the statistics concerning road lengths and vehicle kilometres. The results of the study support the supposition that a sudden traffic growth change has an unfavourable effect on the accident risk.