**6.11 Local hazard warning**

If a hazard occurs far away in front of the vehicle, so that the driver cannot see it, this system will warn him. By the means of communication, it is possible, to transfer this information over long distances. A usable frequency has to be allocated. Local Hazard Warning [14, 15] is a system that uses short-range communication between cars, and between a car and its surroundings, to give drivers early warning of safety hazards. For example, a car equipped with Local Hazard Warning might issue a warning to other vehicles if it had broken down in the middle of a carriageway or had been involved in a collision. Similarly, emergency vehicles equipped with such a system might send a signal to nearby vehicles to warn them of their presence, or temporary roadwork barriers could issue for such warnings. As well as transmitting such warnings, cars equipped with Local Hazard Warning can also receive these signals and use them to alert the driver to the danger [16].
