CENTRAL CONTROL SYSTEM SURVEY

Rapid transit properties require some form of central to coordinate and manage overall vehicle flows. Central control involves making tactical and strategic decisions as the flow of traffic is affected by random variables ranging from fluctuations in passenger demand to mechanical failures in individual vehicles. A good central control system maximizes operating efficiency and level of service under the constraints of the operating environment, system geometry, and available equipment. The number of tasks performed by central control at a given property indicates the level of centralization of control in the system. At some properties control is highly distributed and central control functions primarily as a point of coordination for dealing with schedule disruptions and emergencies. At other properties, mainly those with highly automated systems, there are no operating personnel performing control at a local level, and central control performs all of the functions and tasks. The purpose of this survey was to provide descriptions of the state-of-the-art of rapid transit central control systems in the United States. The survey results will provide preliminary information of the advances in control technology, such as displays, communication systems, control algorithms, and to what extent automation can facilitate rapid transit operations. The survey focused on the central control functions of schedule creation, schedule implementation, schedule maintenance, and failure managements. These functions are the most complex and tend to have the most direct impact on system performance. The five properties surveyed were the Chicago Transit Authority (CTA), the Massachusetts Bay Transit Authority (MBTA), the New York City Transit Authority (NYCTA), the Washington Metropolitan Area Transit Authority (WMATA), and the Bay Area Rapid Transit District (BART).