Stopping-Distance Analysis

This paper discusses a method of plotting and comparing the theoretical, required, and measured stopping distance as required by the U. S. Department of Transportation. The high coefficient stopping-distance requirements have been extrapolated to American Society for Testing and Materials (ASTM) skid numbers over a range of 50 to 120. This will give the brake system designer more confidence in test results on a skid number surface.

A graphical technique has been developed which enables the brake system designer to systematically compare predicted and actual performance of various brake system designs on a variety of tire-road coefficients with DOT requirements for the same conditions. Sample graphs are shown along with the instructions for carrying out the procedure.