Samenvatting
Several notions of risk are listed (1) risk as a label for the accident involvement rate relative to an exposure measure (2) risk as a characteristic of physical situation, based either on measures of accident rates, or on logical causal analysis, or on intuition (3) risk as a descriptive of certain driving behaviour, risk taking as a personal disposition, risk as a phenomenological experience in drivers in traffic, and (4) risk as a societal cost associated with the use of transportation systems.