Research On Brake Mark For Estimating Speed Of Traffic Accident Vehicle

The quantity of vehicle increased year by year. By following, the amount of traffic accident cases grew rapidly. Traffic accident appraisals are the major means of judging the cause of the accident. They also provide important supports for partition accident responsibility and disposal subsequent legal matters. Speed estimation as the higher difficulty in traffic accident appraisals, is increasingly arousing social attention. As a common evidence in traffic accident scene, brake mark is extremely important to speed estimation.In this paper, the key factors affecting the generating of brake mark were found out by means of mechanical analysis of tire and vehicle model. A test system was designed to observe brake mark. Then vehicle braking tests were carried out. In order to make sure the calculation could apply to every accident vehicle, MFDD was involved into the method according to the national standards. Through the analysis of experimental data, the method of calculating the speed at the startpoint of brake mark was determined. A improved method of calculating the initial braking speed was mentioned. By comparing two methods, the results of improved method got more closer to the actual initial braking speed.