The braking system permits the driver to slow or stop the rotation of the tires. The friction of the tires against the road surface will then slow and/or stop the vehicle. Modern vehicles are equipped with two braking systems: a dual hydraulic brake system and a mechanical brake system (parking or emergency brake).
Good brakes are essential for the safe operation of a vehicle. The life expectancy and performance of brakes depends on how they are used and maintained. Braking distance is the distance the vehicle travels once the brakes are applied. Experience and skill in braking, the kinetic energy of the vehicle, the mechanical condition of the vehicle, and road conditions all come into play. Other factors that affect braking distances are roadway surface, hills, and loads.