Summarized in this paper are recent governnent-sponsored studies to deternine the effectiveness of various rnethods for reducing wheer,/rail curving forces and resulting wear and conponent failure on Us transit properties. It descríbes the factors affecting the trade-off bethreen curving performance and truck stability as it affects ride quality and the potential for derailment. A simplified description of truck-curving nechanics is presented, outlíning three sources of lateral wheel/rai1 forces and three key methods for reducing those forces. References to more detailed papers and reports are included. Finally, the results of wheel,/rail force measurements nade for various truck and track con-figuratíons are presented and compared with theory. It is concluded that reduc-tions in curving forces of up to 75 percent can be obtained by using tapered wheels and softening the longitudínaI primary suspenslon or incorporating steerable trucks, or both.

Wheel,/rail wear and related component failures have plagued transit systems since their inception at the turn of the century. In recent years, however, reports of such problems have occurred with increasing frequency. The Transportation Systems Center (TSC) sponsored by UMTA, US Department of Transportation, has conducted studies and experiments to deterrnine