This article outlines a method of evaluating a 'local queue warning system', in principle intended only to warn drivers of unexpected congestion at known discontinuities of the road geomctry (bottleneck) and give them advisory speed indications. A prerequisite for installing this system is therefore that the causes and locations of possible queue formations are known in advance. Such systems have already been installed on the A16 motorway near Dordrecht, where a narrow bridge forms the boltleneck, and on two motorways merging south of the Velser Tunnel. In the latter case it is not only a matter of queue warning, but also of merging two streams of traffic. A comparable warning sytem was recently put into operation in West Germany, on the motorway between Stuttgart and Munich - the bottleneck there is a long, steep incline. The local queue warning system was selected for evaluation because a scheme for evaluating this type of system may also be used, with slight modifications, in the evaluation of other types of warning system. The method is designed to determine the effect of the system in operation. Any effects deriving solely from the presence of the system are ignored in this article. (Author/publisher)
Abstract