What is a critical speed scuff?

What is a critical speed scuff?

• A. A mark left by a tire that is sliding and rolling at the same time; also called a yaw mark; will show striations
• B. A mark left when the car is parked
• C. A mark from braking without sliding
• D. A mark from wheel spin only

Answer: (A)

A critical speed scuff is a tire mark created when the tire is sliding and rolling at the same time, producing a yaw mark with visible striations. As the vehicle loses control or changes direction, the tread scrubs across the pavement while the wheel continues to rotate, leaving a scuffed line with fine parallel scratches that point in the direction of travel. This combination of slip and roll distinguishes it from a mark made by braking without sliding, a parked-tire mark, or a mark from wheel spin alone. Investigators look at the presence of the striations and the yaw-like angle to infer how the vehicle was moving at the moment the tire began to slide.

A critical speed scuff is a tire mark created when the tire is sliding and rolling at the same time, producing a yaw mark with visible striations. As the vehicle loses control or changes direction, the tread scrubs across the pavement while the wheel continues to rotate, leaving a scuffed line with fine parallel scratches that point in the direction of travel. This combination of slip and roll distinguishes it from a mark made by braking without sliding, a parked-tire mark, or a mark from wheel spin alone. Investigators look at the presence of the striations and the yaw-like angle to infer how the vehicle was moving at the moment the tire began to slide.