Skip skid marks should be measured in which manner?

Skip skid marks should be measured in which manner?

• A. Ignore skips
• B. Measure only the first and last tire marks
• C. Measure entire distance (skips should be less than 1 foot)
• D. Measure only the gaps

Answer: (C)

Measuring the full distance the tire was skidding captures the true stopping distance. The total skid length reflects how far the vehicle traveled while the tires were locked or slipping, which is what you use with pavement friction data to estimate speed at impact. Small gaps between tire marks are acceptable to include as long as they’re short—typically less than a foot—because they don’t meaningfully change the overall distance. If gaps exceed about a foot, you should measure each continuous skid segment and then sum them, noting the gaps, so the measurement still represents the actual distance the tires slid. This approach avoids underestimating the stopping distance and keeps the data consistent for speed calculations.

Measuring the full distance the tire was skidding captures the true stopping distance. The total skid length reflects how far the vehicle traveled while the tires were locked or slipping, which is what you use with pavement friction data to estimate speed at impact. Small gaps between tire marks are acceptable to include as long as they’re short—typically less than a foot—because they don’t meaningfully change the overall distance. If gaps exceed about a foot, you should measure each continuous skid segment and then sum them, noting the gaps, so the measurement still represents the actual distance the tires slid. This approach avoids underestimating the stopping distance and keeps the data consistent for speed calculations.