This project summary report summarizes the research performed in Texas Department of Transportation (TxDOT) Project 0-4772. Dynamic message signs (DMSs), also referred to as changeable message signs and variable message signs, are used to communicate traffic information to motorists. The goal of this three-year research study was to provide TxDOT with objective guidelines and a methodological framework for evaluating the influence of DMS systems during periods of congestion or incidents, or under normal traffic conditions. Researchers performed a literature review, conducted surveys, identified and categorized performance measures, proposed an evaluation framework, explored the functionality of this proposed framework, and then revised the framework. The project also sought to identify DMS benefits quantified in economic terms, though there are significant practical and conceptual limitations to accomplishing this type of analysis. Researchers proposed guidelines that include a range of conditions to address all contingency scenarios, including application locations (urban-rural), traffic flow conditions (incident-normal), level of assessment (quantitative-qualitative), time period of analysis (before-after), and availability of data. These guidelines enable TxDOT engineers to measure the effectiveness of existing DMS systems and to validate the implementation and efficient operation of future systems. (Author/publisher)
Samenvatting