抄録
Car dynamics of railway is originally influenced by the interaction between wheel and rail. So with observing these interactual forces, car dynamic behaviors and conditions of the car are able to be evaluated. In this paper the method of observing wheel-rail interaction forces and these results are presented. And in another research, the technics of controlling friction between wheel and rail have been developed and practically used with injecting friction modifier to the top of low rail by the authors. For practical application case of observing these interactual forces, correlation between car dynamics behavior and wheel-rail interaction friction has been evaluated.