
267Accident Reconstruction
degree of engineering certainty. In most cases we are dealing with automobile tire rub-
ber on concrete or asphalt so that the kinetic coecient of friction is about 0.8 on a good
dry surface and as low as 0.3 on a slippery wet surface. On ice the kinetic coecient of
friction may drop to a dangerously slippery value of 0.1 or less. In some instances, when
a vehicle overturns, the coecient of friction of metal on the road surface may need to be
considered. Table 9.1, which has been reproduced from a multitude of sources including
the author’s experiments, lists typical values of the frictional coecient. Note that some ...