Opinion ID: 1788754
Heading Depth: 1
Heading Rank: 5

Heading: Observing and Measuring

Text: Measurements to locate yawmarks are much more complicated than those to locate skidmarks. Simple measurements of the length of the marks are not much use; measurements must be sufficient to plot the marks on a map. That means locating a spot on each mark at 10- or 20-ft (15-meter) intervals as explained in Topic 828. Direction of striations. When examining yawmarks, look for striations, and if any are visible, note their direction with respect to the mark. Perhaps the best way to do this is to photograph them, but they can also be shown on a field sketch made to record measurements. On such a field sketch, a single, continuous, curved line can represent the path of the tire. If striations show along the yawmark, indicate their angle of slippage by little cross marks as in Exhibit 64.