During road trips and drives along long, open highways, cruise control is your best friend. It allows you to set a specific speed, and take your foot off the accelerator for a while, resetting when you press on the brake pedal. However, when speed constantly changes from traffic fluctuations and passing, it may seem like an unnecessary feature.
Adaptive cruise control (ACC) is a semi-autonomous feature in some cars that automatically slows down and speeds up based on traffic flow. The driver sets the maximum speed, just like regular cruise control, and a radar sensor looks out for traffic ahead, focuses on the car directly in front, and instructs its vehicle to stay a specified time-distance behind — the “following distance” the driver selects.
Adaptive cruise control eases driver stress by operating effectively in stop-and-go, rush-hour commute traffic. It can automatically switch from 65 mph to a crawling pace without driver action. Many ACC systems nowadays also include a pre-crash function that can start breaking should emergencies arise. There are 3 basic types:
Partial ACC: Partial ACC cars tend to be less expensive, but they only operate at speeds higher than 20-25mph.
Full Speed Range ACC: Full range can bring cars to a total stop, but the ACC system will need reactivation to re-achieve following distance.
Stop and Go ACC: Also known as Traffic Jam Assist, these ACC systems will automatically restart after completely stopping.
How Adaptive Cruise Control Works
Also known as active cruise control, autonomous cruise control, or intelligent cruise control, the adaptive cruise control system measures distance using a small radar in the car’s front end, a laser, or even stereoscopic cameras. It operates at all times of the day but loses some functionality in poor weather conditions.
To engage ACC, the driver performs the following 4 actions:
- The driver turns on the ACC and presses the set button once the desired speed is reached.
- The speed can be tweaked in small 1-5mph increments using the “+” or “-” buttons.
- The driver sets the gap between themselves and the car ahead, typically a differentiation between short, medium, and long distances indicated by numbered icons or feet.
- An instrument panel shows a display of the cars it detects ahead, adding additional ones as they appear. It constantly detects any vehicles or obstacles that arise.
It’s recommended to start out with the largest following distance. Drivers new to ACC tend to become nervous when the car comes close to the one ahead without their foot on the brake pedal. Most of these systems also come with accident avoidance and collision warning features, like emergency braking and alert lights, to help the driver maintain a safe distance.
Benefits of Adaptive Cruise Control
Despite being an unnerving system to engage at first, adaptive cruise control contains 3 compelling benefits compared to normal driving:
Convenience: On long drives, adaptive cruise control can help the driver relax and rely on his or her car for some time — without completely taking eyes off the road. If you have Traffic Jam Assist, ACC can also make your daily commute immensely less stressful.
Speed Consistency: ACC can keep your car moving at a constant speed within the legal limit. This can be especially helpful on road trips, when an open highway and other distractions may cause you to press harder on the gas pedal.
Fuel Efficiency: Driving style is one of the main contributors to fuel economy. Constantly readjusting speed burns up more fuel. ACC will only use the accelerator and braking system when absolutely necessary.
Adaptive cruise control is an important feature of the development of self-driving cars. Fully autonomous vehicles will need ACC to track the cars ahead of them as well as those on the side beginning lane changes. While it will be critical to cars of the future, current drivers have much to gain from cars that already utilize ACC. Car manufacturers today with ACC include Acura, BMW, Chevrolet, Ford, Subaru, Toyota, Volvo, and many more.
While ACC is an innovative feature progressing automotive technology, the human driver remains responsible for all actions behind the wheel. Drivers can lean on adaptive cruise control when the situation allows but always need to keep their eyes on the road.
