Cruise control is a feature of the engine management system in most modern vehicles that allows a vehicle to maintain a specific speed designated by the driver without continued input to the accelerator pedal. Once the vehicle reaches a desired speed on the road, the driver engages the cruise control system by way of the cruise control switch, and the vehicle continues at that speed until the system is disengaged, or the driver steps on the brake pedal.
Cruise control systems have taken many forms since the early days of the automobile. In modern times, these systems have evolved from those relying on vacuum devices to electronically controlled units. The latest systems react to input from special sensors that can detect the distance to the vehicle ahead and adjust the speed accordingly.
The cruise control switch is actually a combination of switches that not only engage and disengage the cruise control system, but allow the speed setting to increase and decrease. In some vehicles, the switch assembly is mounted on a lever attached to the steering column near the steering wheel, whereas in other vehicles it is integrated into the steering wheel itself.