The use of a laboratory simulator to evaluate the performance of wheel slip control systems under controlled operating conditions is reported. It is shown how an analog computer can be interconnected with a hydraulic brake system and wheel slip control hardware to form a hybrid simulation of a vehicle installation. An analog computer can also be used to simulate vehicle dynamics and tire-to-road friction characteristics. Simulator accuracy is established by correlating laboratory results with road data. Advantages and disadvantages of using the simulator in lieu of experimental road testing are pointed out.