How to Estimate Car Skid Distance
- 1). Look up the speed the vehicle is traveling in miles per hour. This can be the actual speed on the speedometer, or a any other value, such as speed limit or maximum vehicle speed.
- 2). Reference the coefficient of friction for the road surface. These can be found in most physics books. Dry, tar roads are about 1.0. Wet, tar roads are around 0.5.
- 3). Use the formula: Skid distance (in feet) = (speed * speed) / (30 * coefficient of friction) As an example, say you were traveling 60 miles per hour on dry, tar roads where the coefficient of friction = 1: skid distance = (60 * 60) / (30 * 1); skid distance = 3,600 / 30; skid distance = 120 feet.