Money gets won or lost on this number because it can change a crash from "you were driving too fast" to "the road had almost no grip." In a claim, lawyers, insurers, and reconstruction experts use it to estimate speed, braking distance, and whether a driver could realistically stop or steer away. Get the number wrong, and the whole story of the wreck can tilt the wrong way.

The coefficient of friction is a measurement of how much resistance exists between two surfaces sliding or trying to slide against each other. In crash work, that usually means a tire against pavement, gravel, ice, or snow. A higher coefficient means more traction and shorter stopping distances. A lower one means less grip and more sliding. Dry asphalt is usually high. Glare ice in a North Dakota winter can be brutally low. That is why the same braking effort on I-94 can stop a vehicle fine one day and send it skating the next.

For an injury case, this number often feeds the math behind accident reconstruction, skid-mark analysis, and speed estimates. It can support or wreck arguments about negligence, comparative fault, and whether a driver had a fair chance to avoid impact. Under North Dakota's modified comparative fault rule, N.D.C.C. § 32-03.2-02, fault percentage directly affects recovery, so a bad friction estimate can hit your wallet hard.