What is Adaptive Cruise Control? How ACC Works

By keeping pace with the car ahead, up to the set cruising speed, and even slowing down to a stop in traffic, Adaptive Cruise Control (ACC) can help reduce driver fatigue and improve safety. It deploys a high-tech mix of sensors, cameras, and computers combined with the car’s brakes, powertrain, and other systems.

Here’s everything you need to know before optioning your next car with adaptive (radar) cruise control.

What is Adaptive Cruise Control?

Start by understanding standard cruise control. It’s a feature that will hold the car at your set speed by adjusting throttle (gas pedal) and brake inputs automatically. On older cars, this is mechanical — the switch on the steering column is connected to a sort of clamp on the throttle cable. Using mechanical wheel speed sensors, the cruise control mechanism maintains, adds, or reduces throttle and, if needed, applies the brake to slow down.

Modern cars do all this with a computerized system and digital sensors. But standard cruise control only maintains the speed you set it, no matter what’s ahead — it doesn’t adapt to the car’s surroundings.

Adaptive Cruise Control can “see” the car ahead with a combination of cameras, radar sensors, and even sometimes lasers (LiDAR), depending on the make and model. The driver can select a safe following distance, and then the adaptive system constantly measures the distance and speed of the car ahead so it can tell the car how to react.

When the car ahead speeds up, your car will, too, up to whatever speed you set the cruise limit at. If they slow down, your car’s sensors and cameras detect it getting closer and will decelerate, brake, and alert the driver. If another car enters the lane between you and that car, the adaptive cruise system will readjust your car’s speed to now follow that car safely.

In an emergency stop, some Adaptive Cruise Control systems can also apply the brakes and alert the driver but would be paired with frontal collision aids for ultimate effect. All of the system’s actions are communicated to the driver through dashboard visuals, sounds, and even vibrations in the seat.

Adaptive Cruise Control typically works even at slow speeds, meaning it can handle some stop-and-go traffic. Reducing the amount of throttle and braking inputs from the driver can reduce fatigue while they continue to handle steering inputs and overall situational awareness.

How Does Adaptive Cruise Control Work?

To understand ACC, you must get to know the technological components involved. These include:

  • Radar sensors (typically in the car’s front grill) that detect the distance and speed of the car ahead by bouncing radio waves off it and measuring how long it takes them to return
  • Cameras that see traffic, lane markings, and potentially other things in the road
  • Computers to process real-time images and sensor data and determine throttle and braking inputs
  • Interactive driver controls that enable a custom following distance as well as speed, acceleration, and coasting
  • Driver override capability to immediately relinquish control when the driver takes over or turns off the system
  • Standard cruise control components, including throttle and braking connections, which now have a new layer of control

When the driver activates the ACC system, setting their cruising speed and following gap, the cameras and radar sensors begin monitoring the car or space ahead of the driver. They feed data into the ACC’s computer, which makes thousands of decisions per second to keep the car steady, accelerating, or decelerating. That computer is constantly telling the car how much throttle or brake to apply.

However, it’s not a replacement for the driver’s control and attentiveness. ACC relies on the driver to remain aware even though it adds extra sets of “eyes” — and a foot on the brake — to improve reaction time.

Adaptive Cruise Control is most useful in highway and traffic driving, where there’s a car ahead to monitor. It also works best in clear weather, when both the camera lens and the view ahead are mostly unobstructed and clean. It’s not as useful on an empty highway when there’s no traffic to monitor or on twisting roads that might require more manual steering, throttle, and brake input.

If dirt, snow, ice, or other obstructions get in the way of the ACC’s cameras or sensors, it might not work correctly. Typically, the system will then alert the driver that it can't be activated until it’s been cleaned. Foggy, rainy, snowy, or otherwise hazy weather can interfere with the system as well.

When ACC isn’t wanted, needed, or available, the driver could still choose to activate traditional cruise control. This might require a different button or other method to toggle between adaptive and standard cruise control.

While ACC is no replacement for attentive driving, it can help the driver achieve safer, more comfortable, and even more fuel-efficient cruising.

Key Benefits of Adaptive Cruise Control

Is Adaptive Cruise Control worth it? Discover its primary benefits and decide for yourself. Given ACC is an in-demand feature cropping up in more and more models, most drivers seem to think it’s an option box worth selecting.

ACC Can Help You Drive Safer

With multiple cameras and radar sensors aboard, plus computer-quick activation of throttle and braking, ACC is like having an extra set of eyes on the road and an extra foot on the pedals. With an automatically consistent distance behind the car ahead, you can keep a safer space between.

More space between plus quicker reaction times can reduce the chance of rear-end collisions caused by the car ahead suddenly stopping, slowing down, or changing lanes.

It can also make the drive safer by lessening the cognitive load — or mental work — of the driver. The impact of ACC on overall driving safety is amplified when combined with other features, such as rear cross-traffic alert for those parking lot moments.

ACC Can Reduce Driver Fatigue

Highway hypnosis, or the eerie sense of dissociation experienced by weary long-distance drivers, is often a result of that person’s mental fatigue. Driving takes all the senses and constant spatial awareness in all directions. It’s a task of nearly endless inputs, decisions, reactions, and risks.

That’s a lot of work for the driver’s brain — but an ACC system can help reduce some of it and in turn help the driver feel more comfortable, relaxed, and energized. By reducing that constant cognitive workload, automating repetitive tasks, and adding a layer of vision, ACC can help a driver feel less drained after driving hours at a time.

That also means the driver is less likely to be caught off guard when they get cut off, encounter stopped traffic, or deal with unpredictable pulses in traffic speed.

ACC Can Lead to More Fuel-Efficient Driving

With a steadier speed over a long distance, ACC can work with the car’s other systems to keep the powertrain operating at its most efficient level. Without it, the driver’s unsteady throttle inputs, unnecessary braking (which requires extra throttle to catch up), and inconsistent following gaps chip away at fuel efficiency.

ACC’s flexibility and capability also make it safer, better, and usable in more situations than traditional cruise control, expanding the opportunities for smoother, more efficient driving.

How Does ACC Work with Other Safety Features?

In the automotive industry, capabilities like adaptive cruise control fall under the category of ADAS, or advanced driver assistance systems.

The Mitsubishi Outlander, for instance, offers Adaptive Cruise Control as part of its MI-PILOT system, which covers Stop & Go, Lane Keep Assist, and Traffic Sign Recognition. It can also include:

  • Forward Collision Mitigation (FCM)
  • Blind Spot Warning (BSW)
  • Lane Change Assist (LCA)
  • Lane Departure Warning and Prevention (LDW & LDP)
  • Driver Attention Alert (DAA)
  • Automatic High Beam (AHB)
  • Hill Descent Control (HDC)
  • Trailer Stability Assist (TSA)
  • Multi View Camera System (MVCS)

Together, these systems can create a safer, easier, and more enjoyable driving experience on the highway, in the parking lot, and during tricky scenarios like towing or descending mountains.

For instance, ACC can keep the car cruising steadily while Blind Spot Warning alerts the driver not to change lanes. Or it can speed up into open space ahead after the lane-change assist feature takes advantage of a gap in traffic.

Alongside a Forward Collision Mitigation System, ACC can also help avoid dangerous accidents caused by traffic ahead suddenly stopping or slowing down. ADAS features work together to maximize their collective benefit and often share cameras, sensors, and computers to do so instantly and effectively.

Adaptive Cruise Control might also be part of an advanced suite of innovations. In Mitsubishi Motors models like the Eclipse Cross, Outlander and Outlander PHEV, those include:

  • Super All-Wheel Control (S-AWC) for enhanced performance and multiple drive modes
  • MIVEC engine technology (Mitsubishi Motors' Innovative Valve Timing Electronic Control) to optimize performance and efficiency
  • Adaptive shift technology, Innovative Vehicle Electronic Control System (INVECS), for smarter transmission programming
  • MITSUBISHI CONNECT, a mobile app to control cabin comfort, find your vehicle, and more
  • Active Stability and Traction Control (ASC) to counteract slippage and keep control
  • MiEV (Mitsubishi Innovative Electric Vehicle) technology for precise powertrain electrification

These features help drivers achieve a more modern, comfortable, and confident overall car ownership experience.

Adaptive Cruise Control Changes the Game for Modern Drivers

Adaptive Cruise Control can make driving safer, easier, and more enjoyable by automatically speeding up and slowing down to keep pace with traffic ahead. Try Adaptive Cruise Control for yourself in the 2025 Mitsubishi Outlander PHEV and Outlander, which includes ACC as part of its MI-PILOT ADAS capabilities.