Real-world evaluation of C2X-road side warning devices

Road side warning devices play an important role in car-to-car communication. Interestingly however, a detailed experimental evaluation of such devices is missing. Furthermore, although these devices should be able to perform self-positioning to work properly, little attention has been paid to this: mostly, it is assumed that GPS hardware could be used. In this paper, we show that road side warning devices can use information from vehicular beacon broadcasts to approximate their position without dedicated positioning hardware. We analyze existing techniques for this and discover that a straight forward approach leads to a high lateral positioning error that can prevent the determination of the traffic flow actually affected by the hazard. We present an algorithm to overcome this and evaluate our concept in an extensive experimental study.