Why Do Tires Leave Skid Marks?

The rubber on the tires is responsible for the "skid" marks.

Seeing skid marks on the road often tells you that a vehicle stopped suddenly or took off quickly, but not much more than that. The skid marks actually are rubber left on the road from the sudden stop or start.

Cause

Tires leave skid marks when they lock up and are at rest with your vehicle, but they are not at rest with the road and the car continues to slide.

Types

There are different types of skid marks, including those just just leave a skid mark due to rubber transfer, and those that cause a rubber transfer and erasure of the concrete. Tires also can leave "skid" marks on other surfaces, such as other cars.

Significance

Skid and other tire marks can tell investigators how fast a vehicle was traveling at the time of the skid, what type of tires left the mark, where it hit the other vehicle (in case of an accident), if the driver had control of the vehicle, and what the driver and tires were doing (which direction they were traveling, and if they were or were not accelerating).

References

• Expert Pages: The Language of Tire Marks (The Skid and Yaw Mark)