Adaptive Cruise Control

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  • Car with ACC approaching a slower vehicle when travelling at a constant speed (set cruising speed) – Car with ACC reduces speed to match speed of slower vehicle in front – With no vehicle in front, ACC accelerates back to the set speed. - Graphic illustrates the first paragraph of text.

Adaptive Cruise Control (ACC) is an advanced cruise control system that can also keep a set distance behind another vehicle. A sensor in front monitors the distance and relative speed of a vehicle ahead. The ACC system iso symbol for adaptive cruise controlthen adjusts vehicle speed to maintain a driver-selected cruising speed and minimum following distance. If the ACC system detects that the vehicle in front is slowing quickly or if another vehicle cuts in front from another lane, the system automatically applies limited braking and may alert the driver with a warning light or sound. While most systems are radar-based, some use laser detection (Lidar). When not following a vehicle, the ACC automatically accelerates the vehicle to the preset speed.

More advanced systems will slow the vehicle all the way to a stop in stop-and-go traffic.


  • Drivers set desired speed and following distance.
  • Standard ACC systems’ ranges of operation vary by make.
    • Systems can range from 100 to 200 m depending on the system and if the object is moving or at a stop. Systems with video camera can extend range to 250 m.
    • Standard ACC does not react below 30 km/h.
  • Stop-and-go systems operate under 30 km/h down to vehicle standstill. With a stop-and-go system, if the vehicle ahead is stopped and moves forward within 3 seconds, the ACC vehicle follows automatically. If longer than 3 seconds, the driver must re-activate the system by stepping on the accelerator

Things to keep in mind

  • The driver is responsible to keep control of the vehicle and keeping his/her attention on driving.
  • The driver can accelerate or brake at anytime as with standard cruise control.
  • Drivers should use caution when passing.
  • Drivers may need to brake to avoid a crash if the vehicle in front brakes sharply, for example.

Laser systems do not detect and track vehicles well in poor weather conditions or very dirty vehicles that don’t reflect enough light.

System may not respond to stopped vehicles.

Drivers are encouraged to read the owner’s manual to become familiar with the system and the conditions when system operation is different or is not guaranteed.

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