Variable Message Signs (VMS) have been used on motorways and express routes in Paris to inform motorists of the forecast travel time between motorway interchanges. The paper examines the effect of the experiment over a period from May to July 1994. Estimates of journey time were calculated using the method proposed by the author based on flow, carriageway occupancy rate and average speed. Predicted and measured travel times were compared. Inductive loop sensors, spaced at 500m intervals are used to provide input information for the predictions. Travel time for a route is automatically updated at regular one minute intervals. Maps were made of traffic conditions showing congestion contours to compare the effect of the new message signs with the normal queue length display. Surveys were made to obtain the reactions of several thousand motorists as they left the system.
Samenvatting