I agree with Bob on this and can add the following....many "marks" described as shoe scuffs involve the depositing of shoe material on the surface, and the color can vary from the original visible color of the shoe material. But, many also involve the removal or cleaning of the surface - sort of a "squeegee effect," which, on a dark surface can create the appearance of a black mark when, in fact, the roadway surface was "cleaned" or abraded by the sliding shoe. And, of course, there can be a combination of the two effects. Good luck!
Wesley Vandiver, Senior Consultant
Collision and Injury Dynamics, Inc.