This paper deals with an examination of motorcycle accidents in Ottawa, Canada during the summer months of 1973. Among the principle objectives of the study was to investigate in some detail the actual mechanics of motorcycle collisions, to categorize such collisions in terms of the kinematic behavior of the vehicles and motorcycle occupants and to examine the mitigating circumstances in each accident. Of particular concern has been an examination of the accident causative factors and the injuryproducing mechanisms. 1:32 scale models have been used to reconstruct the accident and have been employed in providing a graphic description of the various precrash, crash and post-crash geometries.