BMW Car-to-X Communication, Left Turn Assistant

The left turn assistant is activated automatically in the BMW 5 Series test vehicle as soon as the car's sensors detect that it is entering the left-turn lane and the car registers the driver's wish to turn off. Recognition of the left-turn lane takes place on two levels. The vehicle positioning function of the navigation system allows the location of the car to be fixed to within a metre at intersections. And a mono camera, comparable with standard cameras already in use, registers the turn-off lane markings and lane borders on the road. With the left turn assistant activated, three laser scanners in the front end of the car map the area up to 100 metres in front of the car. The laser scanners pick up not only cars and trucks, but also motorcycles. If the sensors detect vehicles approaching from the opposite direction but the car continues to move into the intersection, the left turn assistant activates an automatic braking input in a low speed range up to 10 km/h to prevent a collision. At the same time, a warning sound and relevant warning symbols in the instrument cluster and Head-Up Display advise the driver of the reason for the intervention. This automated action is triggered deliberately without a prior warning stage, as a rapid response is vital in this situation to prevent the car from moving into the intersection and presenting an obstacle to oncoming traffic. If the driver first had to react to a warning, the car would continue forward into the collision area and an accident would no longer be avoidable.