A critical speed scuff is defined as which type of tire mark?

A critical speed scuff is defined as which type of tire mark?

• A. A tire mark that is rotating
• B. A tire mark that is both rotating and slipping
• C. A tire mark produced by braking
• D. A tire mark left by stationary tires

Answer: (B)

A critical speed scuff occurs when a tire is still turning while slipping against the road. The tire’s tread is being dragged across the pavement, not just rolling freely, so the contact patch scrubs and leaves a smeared, curved mark that reflects both rotation and relative motion between tire and surface. This combination—rotation plus slip—defines the scuff and distinguishes it from marks made by a rotating tire with no slip or by a tire that is fully skidding with no rotation. In practice, this type of mark indicates the vehicle was moving and the tire was not gripping the road perfectly, often at higher speeds or during aggressive maneuvers.

A critical speed scuff occurs when a tire is still turning while slipping against the road. The tire’s tread is being dragged across the pavement, not just rolling freely, so the contact patch scrubs and leaves a smeared, curved mark that reflects both rotation and relative motion between tire and surface. This combination—rotation plus slip—defines the scuff and distinguishes it from marks made by a rotating tire with no slip or by a tire that is fully skidding with no rotation. In practice, this type of mark indicates the vehicle was moving and the tire was not gripping the road perfectly, often at higher speeds or during aggressive maneuvers.