Skid number : speed gradients on highway surfaces. Paper prepared for the 55th Annual Meeting of the Transportation Research Board TRB, Washington, D.C., January 1976.

This paper was derived from an investigation of three major factors that influence the skid number-speed gradient, termed "G"-tire tread depth, water film, and pavement surface texture. However, because of space limitations only the effect of pavement surface is discussed in detail here. The objective of the paper is to identify the G's of various pavement surfaces. The measurement of texture is not considered. Surfaces with like gradients are groups and general similarities in their textures are noted.