Road Travel Time Information on VMS and Traffic Congestion

Some years ago, progress in road telematics had made it possible to introduce time travel information in real time on VMS devices. Such information can lead road users to avoid congested areas as well as to waiting in a better condition for the end of the congestion. In a way, they increase congestion, in another way, they reduce it. Our research aimed at explaining the reasons why some people behave in a way and another one in. We assumed that travel time messages may be interpreted from several points of view, depending on driver knowledges in memory, experience and will, and as a result, the decision taken. An enquiry on a group of drivers aimed at analysing mental activity involved in decision taking process will be presented.