A laser-optical system for measuring tire tread depths for treadwear analysis is described. Other tire dimensional parameters that can be measured include the outside diameter, section width, and rib or groove runout of the tire. This noncontact measuring system provides individual rib height information instead of an average groove depth. A cross-sectional profile of the tread can also be generated on an X-Y plotter.A minicomputer is used for both machine control and data acquisition. The programming capability of the minicomputer provides much flexibility in measuring depths on various tread designs and in defining rib heights on worn tires. The system is evaluated in terms of gauge accuracy, system repeatability, comparison with hand measurements, and problems encountered with tread geometries and states of tire wear.