Abstract
The subject of the paper is research needs in the field of daytime accidents between a motorcycle and another vehicle in which the vehicle travelling on the motorcycle's road had priority, and there was an unobstructed line of sight between the other vehicle and the motorcycle ('motorcycle perception accidents'). The paper lists some of the relevant circumstances of motorcycle perception accidents, besides whether or not the other driver physically failed to see the motorcycle, that most accident analysis studies in the relevant literature have failed to investigate.