Cruise control is a system to automatically control the speed of an automobile. The driver sets the speed and the system will take over the throttle of the car to maintain the same speed.

Cruise control was invented in 1945 by the blind inventor and mechanical engineer Ralph Teetor . His idea was born out of the frustration of riding in a car driven by his lawyer, who kept speeding up and slowing down as he talked. The first car with cruise control was introduced by the Chrysler Corporation on the 1958 Chrysler Imperial.

In modern designs, the cruise control may or may not need to be turned on before use – in some designs it is always "on" but not always enabled. Most designs have a separate "on" switch, as well as set, resume, accelerate, and coast functions. The system is operated with controls easily within the driver's reach, usually with two or more buttons on the steering wheel, or with a control stalk.

The driver must bring the car up to speed manually and use a button to set the cruise control to the current speed. Most systems do not allow the use of the cruise control below a certain speed to discourage use in city driving. The car will maintain that speed by actuating the throttle. Most systems can be turned off both explicitly and automatically, when the driver hits the brake or clutch. Cruise control often includes a resume feature to resume the set speed after braking and a coast feature to reset the speed lower without braking. When the cruise control is in effect, the throttle can still be used to accelerate the car, although the car will then slow down until it reaches the previously set speed.

This feature can be handy for long drives across sparsely populated roads, and usually results in better fuel efficiency. It is also known in some places as the "poor man's radar detector", since by using cruise control, a driver who otherwise tends to unconsciously increase speed over the course of a highway journey may avoid a speeding ticket.

Most countries establish that it is illegal to drive within city limits with the cruise control feature activated. Cruise control can also lead to accidents outside of the city, as the lack of need to maintain constant pedal pressure can help lead to highway hypnosis.

External links

• Cruise [Un]Control: Driver sets the cruise control on his vehicle, then slips into the backseat for a nap. (Snopes.com)