The purpose of this research has been to evaluate a VTR system, which records the on-the-spot accident scenes in order to get information how and why traffic accidents occur. This report describes the details of the methodology, test instrumentation and recording procedures of this system and site, explains several examples of the accident caught by this system. The system has been set at an intersection of busy traffic where accidents occur frequently. Two TV cameras were mounted on a high pole built specially for this purpose. The intersection is lighted at nights. The television cameras view over the intersection and the traffic scene is recorded on VTR throughout day and night. But, the record is erased after every two ours except when an accident occurs. The traffic noise and the sound of the accident are recorded simultaneously. The co-ordinates of the intersection roads and the exact time are also recorded being overlapped on VTR.

We caught on-the-spot accident scenes three times in about four months. The records were very helpful for the accident investigation of the police. This system seems very useful for accident investigation and analysis though some revision are necessary.