Abstract
This report is a contribution towards developing a general theory of the relationship between exposure and risk. As a basis for developing such a theory, the concepts of exposure and risk are discussed. It is proposed to define exposure as any event in traffic that has the potential of becoming and accident and places cognitive demands on road users. Events are clearly limited in time and space. Risk is the proportion of events that result in an accident. The basic hypothesis is that there is a negative relationship between the number of events and the risk of accident. Studies illustrating such a relationship are presented. These studies should, however, not be regarded as a stringent test of the basic hypothesis. (Author/publisher)