What Skid Marks Can Tell You About Your Accident

Skid mark measurements can be a very effective tool for determining how an accident occurred (which may determine the party at fault) as well as the force of the collision (which may help explain the severity of your injuries). Typically, skid mark measurement is performed by the investigating police officer and measurements will be identified in the traffic collision report. Unfortunately, measurement and calculation errors are common.

Is it really a skid mark? Skid marks are essentially brake marks, but not all tire marks are caused from braking. Yaw marks or "slip angle" (for example, when the vehicle travels sideways such as losing control in a tight turn) are not skid marks. You can tell the difference between the two by the alignment of tire tread marks: For yaw marks they will be aligned at an angle to the direction of travel and for skid marks they will be parallel to the direction of travel.

Correct skidmark measurement. This is a very common error. If the vehicle makes 4 skid marks of equal length, then you have an easy measurement. However, many times, skid marks from the same vehicle will be different lengths. Using the length of the longest skid mark will produce a higher speed estimate, but this may not always be the best course of action. Using the average length of the marks will produce a more conservative (and lower) speed estimate which is easier to defend on cross-examination.

What if there are no skid marks? One or more tires may not produce skid marks (for example, an inexperienced motorcyclist may fail to use the front brakes in an emergency braking situation or as a result of brake failure). Explaining why the officer did not find skid marks can be just as important as explaining the skid marks the officer did find.

If you or someone you care about has been injured in a motor vehicle or motorcycle accident, please call for a free consultation today. Know your rights!