The program determined the effects of selected modes of disc and drum brake component degradation on vehicle braking performance. The results were used in recommending brake component and system performance limits of degradation and determining a cost-effective means of brake system inspection. The modes of brake degradation evaluated were one front brake contaminated with brake fluid and wheel bearing grease, worn friction materials, thin discs, and thin drums. The evaluation of brakes from one large and one intermediate size automobile was conducted on a two-wheel inertial dynamometer. The dynamometer results were converted into vehicle braking performance with a vehicle handling model and a hybrid computer. The testing approach was verified with vehicle braking tests. A literature survey was conducted and a bibliography is presented.