The Washington Metropolitan Area Transit Authority (Metro) was created by an interstate compact in 1967 to plan, develop, build, finance, and operate a balanced regional transportation system in the national capital area. Metro began building its rail system in 1969, acquired four regional bus systems in 1973, and began operating the first phase of Metrorail in 1976. Today, Metrorail serves 91 stations and has 117 miles of track. Metrobus serves the nation's capital 24 hours a day, seven days a week with 1,500 buses. Metrorail and Metrobus serve a population of approximately 4 million within a 1,500-square mile jurisdiction. Metro began its paratransit service, MetroAccess, in 1994; it provides about 2.3 million trips per year.