Cruise control allows a vehicle to maintain a selected speed regardless of the road surface, even without pressing the pedals. The system reduces driver fatigue, maintains speed limits on long trips, and saves fuel. That’s why many US consumers put cruise control on their top priority list when choosing a car. However, modern vehicles may considerably differ in driver assistants. The Indy Auto Man car experts prepared a comprehensive guide on cruise control types and the pros and cons of this system.
History of invention
Systems that limit the speed are necessary components of any cruise control found in cars since the early 20th century.
The concept of cruise control in its modern form was invented in the 1940s by Ralph Teetor, a brilliant, despite his blindness, engineer-inventor from Indiana. According to legend, Ralph was very annoyed by the driving style of his assistant. Fulfilling the duties of a personal driver, he had the habit of slowing down when he listened to his interlocutor, that is, Teetor himself, and speeding up when he spoke. This kind of jerky driving irritated Ralph, so he found a way to make his driver ride smoothly and maintain the same speed regardless of the conversation.
Titor, considered one of the best automotive engineers of his time, filed a patent for cruise control in 1948. Soon, after minor modifications, his device for automatic vehicle speed control began to appear on the car market. First on expensive models of the Chrysler Corporation (Imperial, New Yorker) and Cadillacs. Subsequently, cruise control gained mass popularity and became standard equipment for most cars. In 1988, Ralph Teetor was included in the Automotive Hall of Fame for his invention.
Types of Cruise Control
There are three types of cruise control:
- The speed limiter is essentially a basic cruise control function that prevents the car from accelerating faster than the set speed limit despite pressing the gas pedal. But if you let go, the car will start to slow down. This function allows you to insure yourself against speed limit violations.
- Passive cruise control is a standard, most common system that maintains a given speed but cannot independently brake when an obstacle is detected and accelerate again independently if the road is clear.
- Active cruise control (ACC) is a modern version of the system with expanded functionality installed in all the safest cars of 2024. Thanks to sensors, radars, lidars, GPS, and other assistants, ACC partially performs the functions of a driver. It sees cars in traffic, can independently maintain a distance from the vehicle in front, brake, and accelerate with it without the participation of a person behind the wheel.
According to international SAE standards, vehicles with active cruise control are considered “level one” autonomous vehicles.
How cruise control maintains vehicle speed
Cruise control remembers the speed value desired by the driver and maintains it. When cruise control is turned on, the speed corresponds to the one selected by the driver. But when driving uphill or downhill, cruise control automatically increases fuel supply or limits it.
The system controls the vehicle’s speed in the same way as the driver – with the help of the accelerator. Older cars with manual throttle control had two cables. One is a throttle valve actuator connected to the gas pedal, and the other is a cruise control cable operated by a pneumatic drive or an electric motor. On modern cars with an electronic gas pedal, the data exchange between the engine ECU and the cruise control unit is managed electronically.
At the same time, unlike a person, cruise control does everything neatly, smoothly, and almost imperceptibly – exactly as Ralph Titor wanted. This not only increases travel comfort but also has a positive effect on fuel efficiency.
Benefits of Cruise Control
The widespread use of the system was facilitated not only by its smooth running but also by other advantages:
- Comfort on long trips. The driver does not need to keep his foot on the pedal.
- Maintaining a safe speed. Correctly set cruise control settings help avoid fines for violating the speed limit.
- Increased fuel efficiency. Smoothly adjusting the fuel supply and driving at the same speed allows you to save on gas stations. Savings can range from 4 to 10%, depending on the car model.
Disadvantages
Cruise control also has its drawbacks like any other system. However, they are specific, and there are very few of them:
- Danger of use in certain weather conditions. It is not recommended to use cruise control on slippery and snowy roads.
- Cruise control operation may reduce the driver’s attention level and ability to react to traffic situations.
- Some studies indicate that a driver accustomed to cruise control loses spatial awareness and may hit the gas instead of the brake in an emergency.
Regardless of the disadvantages, cruise control is indispensable when traveling long distances. It only requires a more responsible attitude and timely maintenance of the vehicle’s electronic systems.
