Dynamic message signs (DMS), also referred to as changeable message signs (CMS) and variable message signs (VMS), have been used for over 30 years to provide traffic information to motorists and have become a prominent component of intelligent transportation systems (ITS). They have become an important component of many advanced traveler information and traffic management systems. DMS allow for the dissemination of real-time traffic information to motorists and are generally deployed in urban areas to inform motorists of traffic conditions (e.g., expected delays, estimated travel times, diversion routes, lane closures). DMS have become an important source of motorist information during incidents, special events, and work zone traffic control. The value of DMS, or any traffic information source, is dependent on two items: (1) The accuracy and usefulness of the information disseminated; (2) Motorists' willingness and ability to understand and utilize the information. The latter point involves the public perception of traffic information technologies. The quality of traffic-related messages as well as the overall presence of DMS affects the public perception. Traffic management agencies must understand that DMS affect public perception even when they are not actively conveying traffic-related information. Motorists may perceive blank signs as inoperable or may question the allocation of resources to technologies that seem to be (from their perspective) underutilized. On the other hand, displaying information not germane to real-time traffic conditions may erode the credibility of DMS and reduce their effectiveness as a traffic management tool. The purpose of the research presented herein was to assess the professional opinion regarding DMS usage during normal traffic conditions.
Abstract