In recent years, the number of accidents involving motorized two-wheelers has steadily increased. Nevertheless, so far few studies exist describing the collision characteristics and injuries to the drivers of motorized two-wheelers.On the basis of 1,206 accidents, the collision characteristics and the injury risks to motor-cyclists and moped drivers have been examined. Epidemiologic features of vehicle registration and accident involvement related to motor-cycle categories are indicated. The risk exposure of motor-cycles and mopeds compared with cars is discussed.The overall injury severity and injuries to the different body areas are indicated for both motor-cyclists and moped drivers. The risk to driver and passenger is compared.A new system has been developed to describe the collision characteristics from the kinematic aspects. The crash situation is indicated by “Collision Types”, the movements in pre-crash, crash and post crash phases are described by the “Trajectory Classification”.The frequency of collision types and the resulting injury severity is pointed out, which leads to possible safety measures being introduced on motor-cycles/mopeds and on cars/trucks. The “Trajectory Classification”, which shows the frequency of typical movements in accidents involving motor-cycles or mopeds is discussed, mainly in respect of the resulting injuries.A proposal for a safety conception for motor-cycles and mopeds is made. The use of safety helmets for both motor-cyclists and moped drivers is postulated.