A vehicle oversteered or cornering at excessive speed results in the tyres of the vehicle losing traction with the road surface. As a result tyre yaw marks may be left on the road surface. Yaw marks are common at fatal collision sites. Various methods are reported to estimate the speed of the vehicle that leaves yaw marks on a road surface. The Victoria Police, Accident Investigation Section conducted 110 tests at Avalon Airport, Victoria, Australia, in February. 1996. Four different vehicles were tested. During testing, variations in tyre pressures, and driver inputs of acceleration, braking and steering over-correction were looked at. The effects of yawing followed by emergency braking with and without ABS braking was further studied. The methods adopted currently by the Victoria Police, Accident Investigation Section in estimating speed from yaw marks were validated and found conservative. Radar speed of the vehicle for each test was compared with speed estimates from the yaw marks. (Author/publisher) For the covering entry of this conference, please see ITRD abstract no. E207978.
Samenvatting