This report is part of the project `Accident patterns and accident rates per road type'. This project focuses on the relation between the various road types in the Netherlands and certain accident and rate patterns. With an accident pattern we mean the distribution of accidents among various accident types (crash opponents, manoeuvres). The accident rate most frequently used for road types is: `the number of injury accidents per million motor vehicle kilometres travelled'’. This part of the project describes the method of calculating the new accident rates (`key data') of the sustainably-safe road categories, after sustainably-safe measures have been implemented. The data used are those used to quantify the safety of present existing types. The calculation method uses changes in accident patterns: the point of departure is the distribution of different accident types on each road type. A distinction is also made between road sections and intersections. The calculation method makes it subsequently possible to differentiate the estimated effects of sustainably-safe measures per accident type, per road type, and road section/intersection; and to calculate them. This produces new `partial key data' per accident type and per sustainably-safe road category. These can be used to calculate new total key data per road category. The calculation method presented is illustrated by a calculation example. The report only presents a calculation method that uses existing key data to arrive at new key data. It does not present the new sustainably-safe key data themselves. The choice of which sustainably-safe measures to be applied, and the ways of estimating their effects, is still the subject of a lot of discussion. The report wishes to stimulate this discussion and contribute towards it. (Author/publisher)
Abstract