In this paper, Sliding Mode Controller (SMC) is proposed to enhance Anti-Lock Brake System (ABS) performance. To verify SMC performance, a real-time Hardware in the loop simulation has been created with a hydraulic brake line. Therefore, the hydraulic brake model and vehicle model should be properly set up to acquire exact simulation results. In addition, the experiment results are compared with that of the commercial ABS with ECU only, and verified how much the performance is improved. The control strategy is to follow the target slip ratio by means of sliding mode controller and secure the vehicle stability while the vehicle braking on various road conditions, such as dry road, wet road, icy road and even split road condition. The driver model is useless on the uniform slip ratio of a straight road. However, the split road has to adopt the driver model. The split road condition has a different slip ratio at each wheel, causing the vehicle to spin out. Test results show that ABS with sliding mode controller has better performance than existing ABS and also ensures improved vehicle stability. Furthermore, the test result on the split road shows how the vehicle will follow the desired path with the driver model and hold the target slip ratio.