In 1996, the U.S. DOT initiated the Metropolitan Model Deployment Initiative (MMDI) to evaluate the value of integrating ITS components, such as Traffic Signal Control, Freeway Management and Incident Management Systems on a regional basis. The MMDI used four regions to serve as model deployment sites (San Antonio, Phoenix, Seattle, and the New York/New Jersey/Connecticut (NY/NJ/CT) area). The main thesis of the MMDI was that benefits delivered by an integrated system of ITS components will be greater than the sum of the benefits provided by the individual parts. Integration of systems and information should lead to a synergy of positive effects on transportation safety and congestion reduction. Independent evaluations of the MMDI deployment sites identified lessons learned on ITS planning and deployment. A summary document entitled, “Deploying and integrating ITS: Twenty Questions and Answers” is based on the MMDI evaluations and provides guidance for ITS project manager on ways to contain costs, assess performance and evaluate projects.
The MMDI set in motion an aggressive schedule of ITS deployment in four regions: San Antonio, Phoenix, Seattle, and New York City metropolitan area (which included parts of three states, New York, New Jersey, Connecticut – NY/NJ/CT). In addition to deployment, the program pursued the region-wide integration of ITS components. Integration should deliver improved benefits through the data sharing of real-time traffic conditions, so, for example, a freeway management system could adjust ramp metering in response to an emergency management system’s detection of a freeway incident.
Evaluation of the ITS deployment in the MMDI identified key characteristics of ITS integration that are relevant today. The following recommendations are based on the experiences of MMDI managers and support ITS project goals of efficiency and productivity.
- Develop a regional ITS architecture with a common data server. A common data server is the backbone of a regional, integrated ITS platform. It facilitates the exchange of data between distinct ITS components in a region, enabling each system to respond to real-time traffic conditions. Each of the four MMDI model sites cited in the evaluation successfully used a common data server for the purpose of collecting data from various sources (e.g., traffic cameras and emergency responders) and then distributing it as actionable information to different users (such as transportation managers of transit systems or highways, emergency responders and the traveling public). An important note is that the servers in the model deployment sites were successful whether they used a central or distributed system.
- Consider a real-time traveler information system as the first ITS component to be deployed in the development of an integrated, regional ITS system. Results from the MMDI show that traveler information systems deliver among the strongest benefits of ITS components deployed. Thus, the MMDI evaluators recommend that regions with individual repositories of traveler- information system in place begin the development of a regional system by first deploying traveler information systems. Among the features of a traveler information system that led to highly successful improvements were 1) point-to-point freeway times provided over the traveler information website as well as changeable message signs, 2) information on the website on roadway and weather conditions that affected roadway conditions, and 3) bus arrival times on web applications for transit users.
- Keep in mind that benefits delivered by ITS integration will most likely take time to reach their potential. The evaluation of the MMDI found that the time frame for realized benefits of integrating ITS can be longer than non-ITS improvements. Very early results may not reveal the benefits that can be delivered months or years later, and there can be longer term benefits that had not been planned. For example, the integration effort in Phoenix led to an unanticipated benefit: the response team (REACT) in Maricopa County now assists local police in county and non-county roadways for incidents and special events in lane closures, diversion of traffic and identification of alternate routes. The effort to integrate led partners to realize the potential benefits if REACT were to provide services to the whole region.
The managers of the model deployment sites found that a strong regional architecture, fortified with a common data server, enabled efficient data exchanges between systems across the region. Also, the evaluation determined that among the ITS components deployed in the MMDI, Traveler Information Systems were the most successful in delivering benefits. Finally, keep in mind that integration may produce unanticipated benefits in the long run in safety and productivity.
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