A vehicle can perform controlled descent using the
anti-lock braking system (ABS) and in some cases
engine braking. If a vehicle accelerates under the
force of gravity, the system will automatically apply brakes to slow down to the desired vehicle speed.
Cruise control buttons can adjust the speed on some vehicles. Applying pressure to the
accelerator or
brake pedal will override the HDC system. Later implementations combine HDC with
traction control and low-range gears and have reduced the set speed to slower than walking pace for extra control. ==History==