On the background of increasing use of ITS the report presents results from a project under the program "ITS on the road towards 2020". The effects of six variable message signs (VMS) in Trondheim on travel times, road safety and the environment were investigated by simulations, user surveys and analyses of speed data. Travel times are likely to be reduced, while crashes are likely to increase when VMS are used to display incident information, according to the results from traffic simulations. The reduction of travel times is not sufficient to outweigh increased crash costs. No positive safety effects were found of congestion warnings, possibly because the VMS were not working as intended. Most road users regard the VMS as useful, even if only few use VMS information to change route choice. Some will change route choice in the case of incidents, but not when travel times or congestion information are shown on VMS. Using VMS to provide information about alternative routes and driving conditions would improve the usefulness of the VMS. (Author/publisher) For the complete report see http://www.toi.no/
Samenvatting