ACC uses a set of intelligent sensors including radar, lidar, lasers, GPS, and cameras. These sensors are placed around a vehicle’s exterior to monitor the road and nearby vehicles. Gathering real-time data on the distance away and speed of the vehicle in front, these sensors allow the ACC system to adjust the car’s speed as-needed. Typically, the driver sets their desired cruising speed when they engage ACC on the highway. The system then automatically accelerates and decelerates to stay at a safe distance from other cars within the flow of traffic.Â
Much like using traditional cruise control, activating ACC is intentionally simple so that a driver can easily use it while keeping their eyes safely on the road. Generally, the dedicated ACC button or switch is located on the steering wheel or control panel. Pressing or toggling this mechanism allows the driver to set their initial cruising speed. In some systems, drivers can also set their desired following distance.Â
While operating, certain ACC systems can take extra measures for safety and convenience purposes:
- Maintaining a particular distance from vehicles ahead
- Making complete stops in traffic and restarting from a complete stop when traffic resumes
- Remaining engaged at low speeds in city traffic
- Anticipating and automatically slowing around upcoming curves
- Adjusting to posted speed limits as they change
Once in operation, the ACC system remains working until the driver disengages by either pressing the brake pedal or manually deactivating the system using the dedicated switch or button. Sometimes, ACC will use visual and audio cues to alert the driver to brake if it detects a possible collision ahead. In these instances, the driver must then re-engage the system once traffic resumes.