Applies to vehicles: with Audi pre sense front or Audi adaptive cruise control
Pre sense front informs you if you are too close to the vehicle in front for an extended period. In certain situations it can warn you if there is a danger of collision, and can initiate the application of the brakes.
Given sufficient time to react, it can assess a dangerous situation where a vehicle in front brakes suddenly or where you are driving fast and approach a much slower vehicle. The pre sense front will not react if it is not in a position to detect the danger.