Wet weather speed zoning. Paper prepared for the 52nd Annual Meeting of the Highway Research Board HRB, Washington, D.C., January 1973.

This paper includes an assimilation of findings from various related skid research efforts to form a basis for equating the available friction at a site (pavement skid resistance) to the expected friction demand for selected manoeuvres. It presents curves to determine, for various pavement frictions, the critical speed for hydroplaning, stopping manoeuvres, cornering manoeuvres, passing manoeuvres, and emergency correcting manoeuvres. A design process to establish the wet weather speed limit is discussed and examples are presented to illustrate the use of the curves.