What Is Adaptive Cruise Control?

Adaptive cruise control (ACC) is similar to standard cruise control in that it maintains a driver’s preset speed once engaged. But unlike basic cruise control, ACC also automatically adjusts a car’s speed based on traffic conditions.

For example, if the car in front of you slows, the system will automatically engage the car’s brakes to slow your speed and maintain a safe distance between you and the car ahead. Once the car in front of you speeds up, the system will resume the set speed.

While not federally mandated, most new cars come with ACC technology.

ACC systems use cameras, sensors and radar technology — or a combination of the three — to monitor the distance between your car and the car in front of you. This technology also automatically accelerates or slows your car, based on your settings and the speed limit.

You can set your speed and following distance, or how much space you want between the car in front of you and your car, with controls typically located on the steering wheel. ACC systems automatically keep your car at the preset speed and distance unless traffic ahead slows or you brake. You can reset your speed and distance at any time while driving.

Adaptive cruise control systems are also often referred to as active cruise control, dynamic cruise control, radar cruise control and intelligent cruise control, among other names. And like its names, the specifics of how the system functions can also vary between vehicle makes and models.

For example, most ACC systems can bring your car to a complete stop if traffic around you stops, then accelerate once traffic picks up again. Other systems, however, don’t have this capability or may not work below certain speeds.

Some ACC systems can anticipate curves and adjust a car’s speed when it’s approaching a curve. However, some ACC systems may not be able to anticipate traffic on curving roads as well as they would on straight ones, and therefore may not be able to adjust a car’s speed accordingly.