Rear-end collisions account for a substantial amount of crashes. The vast majority of rear-end collisions occur at speeds up to 30 km/h, mostly in city traffic. A common cause of these crashes is driver distraction. A rear-end collision might lead to soft-tissue neck injuries for the occupants in both vehicles involved, as well as material damages. The objective of this study is to present and discuss the potential benefit of a production system helping the driver to mitigate and in certain situations avoid rear-end collisions in low speed.

City Safety monitors the traffic in front with the help of a laser sensor that is built into the windscreen’s upper section. It can detect the rear-end of a vehicle in front of the City Safety equipped car. If the driver is about to drive into the vehicle in front and does not react in time, the car brakes itself. The scope for the system is every day low speed scenarios, like cues or entering roundabouts, situations where a large portion of collisions appear due to distracted drivers. City Safety is active at speeds up to 30 km/h. If the relative speed difference between the vehicles is less than 15 km/h it can help the driver to avoid a collision completely. In relative speed differences above 15 km/h up to an absolute speed of 30 km/h the objective is to reduce speed as much as possible before a collision occurs.

Independent evaluation has shown that this technology offers the potential benefits of reducing collisions, leading to a substantial reduction in car damage costs and injuries to the occupants. Based on available statistics and dose-response model techniques, the reduction of impact severity is estimated to have the potential to reduce the risk of soft-tissue neck injuries in the rear-end impacted car by approximately 60%. Real-world retrospective studies of the production system will enable more precise quantification of the effect in the future.