VARIABLE MESSAGE SIGNS ON THE AMSTERDAM RING ROAD, A LITERATURE STUDY INTO ROUTE CHOICE BEHAVIOUR AND THE APPROPRIATE DESIGN

In 1990 the complete motorway ring round Amsterdam will be available for the traffic. For traffic passing Amsterdam it will give a number of route alternatives. For the Transportation and Traffic Research Devision of Rijkswaterstaat, the TNO Institute of Spatial Organisation and the TNO Institute of Perception have carried out a study into the application of variable message signs (VMS) on the motorway road system in the Amsterdam area. Such a system informs travellers about the route they should take to specific destinations, given current traffic conditions. The study has been done by a literature survey and desk research only. The route the VMS indicates should agree with the choice the road user would have made, if he had the correct information on the alternatives available. The most important factors in the route choice are time, distance and congestion. No literature has been found in which the trade-off between these factors by travellers has been established in a quantitative manner. In particular hardly any studies refer to congested networks. Very little has been found about the way a VMS should be designed. Also very little information has been found on the relation between the design and the behaviour of road users when the signs are in operation. It was concluded that with respect to the design of the VMS system it is very important to call driver's attention to the signs when they are in operation by means of a flashing light. Furthermore, the reason for the route diversion should be indicated. (Author/TRRL)