Skid mark

A skid mark is a black strip on the road, the asphalt pavement caused by the rubber marks of a blocking or strongly braked tire and by exudation of the binder ( bitumen ). Usually a skid mark on dry pavement from a delay of 6 m / s ² is drawn.

The locking of the wheel can have two causes:

• Full braking with locked wheels
• Deformations on chassis or body through which the wheel can no longer move freely.

Through the use of antilock braking systems (ABS) and vehicle dynamics control systems (ESP ) for motor vehicles, the development of skid marks is changed. For passenger cars ( cars), the use of ABS, depending on the type of braking and the car used, almost no influence on the development of skid marks. Depending on the quality ( minimum frequency ) and adjustment of the ABS, a braking track at regular intervals be interrupted (often at truck). When using ESP, the braking track have cross- veins, which are indicative of control interventions on the wheels and on the skew angle of the wheels.

From the length of the course and a skid mark, conclusions can be drawn on the details of accidents:

Therefore, skid marks are an important evidence in the elucidation of the question of guilt after traffic accidents. They are often ( etc. and other traces of the accident, such as scratches, lacquer wear, chips, deformation of the hood ) recorded by surveying methods, whereby in particular the Unfallphotogrammetrie (ie the evaluation of accident photos) are of importance.

In addition to the locking of the wheels sideways drifting or skidding of the vehicle is another cause of tire tracks on paved roads.