Since the 1930s, designers have divided the brakesystem into two seperrate circuits. This means that if one of the systems fails, the other can be used for safe braking while still conforming to the legally required minimum delay. Nowadays the following systems are standard: 1. Diagonal split, 2. Split to 2 sets of 3 wheels, 3. Two circuits covering all 4 wheels, 4. One circuit controls all four wheels, the other only the front two wheels. But the most important factor: Press the brake pedal hard in emergency situations in order to stop the car as soon as possible. If the vehicle is fitted with ABS you can steer around obstacles whilst braking.