Cruise control is designed to maintain a fairly constant vehicle speed without the need for driver input. It does this by monitoring road speed and using an electronically controlled actuator to open or close the vehicles throttle.

Cruise control operating switches are usually located either on the steering wheel or on a stalk attached to the steering column.

Apart from the ON OFF switch, there are four main control functions. SET is used to engage the system when the desired speed has been reached. RESUME re-engages the system and brings the vehicle back to the set speed. ACCELERATE and DECELERATE increase or decrease the set speed.

The cruise control function is deactivated when the brake or clutch pedal is depressed, the cancel switch (if fitted) is touched or the main switch is turned off.

Most systems will not operate below about 60 km/h.

Safe use of cruise control

Cruise control can reduce driver distraction by removing the need to constantly monitor vehicle speed, however it should not be used in the city, heavy traffic, wet or slippery conditions or where braking and / or lower speeds are required to negotiate bends.

Conventional cruise control systems have no connection to the vehicles brakes and therefore cannot prevent a vehicle over speeding when travelling down a steep hill.

Intelligent cruise control systems

Intelligent cruise control systems use radar to sense vehicles on the road ahead and can alter the set speed to maintain a safe following distance. Intelligent systems can also apply the vehicles brakes to increase the following distance or slow the vehicle on hills.

Availability

Most vehicle manufacturers offer cruise control as either standard equipment or as an option. There is also a range of aftermarket systems on the market.

Note that different manufacturers may use different terms to those used here.