the average accident involvement of riders classified by variable such as frequency of use type of road, weather and lighting conditions and seasonal effects was calculated from the raw data. this simple univariate analysis does not however yield easily interpretable results because of the complex interactions between these variables and the age, experience and exposure variables already considered. In an attempt to facilitate the interpretation of the data relating to the type of experience to which a rider is exposed, a typology of riders was defined. The underlying concept for this typology was to produce a hierarchy of 'rider dedication' ranging at one extreme from rider who ride in all circumstances including riding in the wet or dark during winter to those who ride only monthly, and only in the summer at the other.