The brake control system comprises a control device to apply the hydraulic brake pressure given at least at one of the wheel cylinders mounted on the front wheels in the case where the slip rate of at least one front wheel is less than that of at least one of the wheels that belongs to a hydraulic pressure circuit that is independent of the circuit to which the front wheel(s) belong(s), at least when the brake pedal is activated. The brake control system has wheel cylinders which are each mounted in operative fashion on a front and rear wheel; a master cylinder to put a brake fluid under pressure in order to supply a brake pressure to the wheel cylinders in response to a depression of the brake pedal; a pair of main pipelines to connect the master cylinder to the wheel cylinders in order to provide a twin circuit hydraulic pressure system; an additional pressure source to put the brake fluid under pressure in order to supply the hydraulic brake pressure to the main pipelines; wheel speed sensors to detect the wheel speeds; a slip-rate calculation device to calculate slip rates of the wheels on the basis of the speeds detected by the sensors.
