Audi pre sense basic networks and compares different vehicle systems to initiate, within system limits, preventive measures to protect the vehicle’s occupants. If the driving situation becomes unstable, the front seat belts are tensioned electrically. Depending on the situation, the windows and – if installed – the sunroof are closed. The hazard warning lights are activated to warn following traffic. Audi pre sense rear uses data from the radar sensors at the rear of the vehicle and calculates, within system limits, the probability of a rear-end collision with the vehicle behind. If a risk of collision with the vehicle behind is detected, the safety measures of Audi pre sense can be triggered.