"Understanding the Potential Impact of Various DMS Messages on Traffic Flow"
Dr. Ali Haghani & Michael Pack
Civil & Environmental Engineering
Knowledge of rapidly changing trafficconditions gives road users the option tomodify their behavior in order to avoiddelays and dangerous situations. Manystates, as part of an Advanced TravelerInformation System (ATIS), have installedDynamic Message Signs (DMS) in order tohelp provide this information.While most agree that DMS are a valuabletool in reaching motorists and conveyingimportant information, there has longbeen speculation that DMS messagescould possibly adversely affect trafficconditions, too. Recent publicity surroundingthe new travel time messageson DMS have rekindled this debate. Thequestion remains: can a message postedonto a DMS adversely affect traffic? Ifso, do all classes of messages have thispotential or do only certain types and/or lengths of messages pose a threat?Another important measure of the valueof a DMS message is its credibility. It is vitallyimportant that travelers believe thata message displayed on a DMS is basedon fact and accurately describes presentroadway conditions. Without consistentlyvalid information, road users will begin toignore DMS messages altogether.This research project will strive to understandthe potential impact of the DMSmessages on traffic flow and evaluatethe quality of the messages posted onthe signs in term of accuracy, timeliness,relevance and usefulness. Additionally theanonymous vehicle tracking feature of theBluetooth sensors will be used for analyzingthe diversion of traffic to the alternativeroutes suggested by the messages asa proxy for drivers’ response to the DMS.