chosen for the color of bus operations on January 8, 1972. The MBTA had primarily been formed to subsidize the suburban commuter rail network. However, the agency also took over unprofitable suburban bus operations – much of which was former streetcar lines – from several private companies. The MBTA took over the Eastern Massachusetts Street Railway in 1968, inheriting large networks based in Lynn and Quincy plus several lines in Norwood and Melrose. (Networks serving Lowell, Lawrence, and Brockton outside the MBTA district were briefly operated by the MBTA. They were transferred to new public agencies: the LRTA in Lowell in 1976, a predecessor of the MVRTA in Lawrence in 1968, and a predecessor of the BAT in Brockton in 1969.) The MBTA began subsidizing Middlesex and Boston Street Railway service based in Newton and Waltham in 1964, and took over the remaining routes in 1972. Five former Service Bus Lines routes in northeast suburbs were taken over in 1975, and a single Brush Hill Transportation line in Milton was taken over in 1980. The geographic scope of the MBTA bus network has remained relatively constant since these additions, though many services have been created, discontinued, and modified during the MBTA era. The openings of new sections of the Red Line (1971, 1980, 1984–85) and the Orange Line (1975–77, 1987) have resulted in significant changes as routes were modified to serve new transfer stations. Three limited-stop crosstown routes were created in 1994 as a prelude to the Urban Ring Project, a never-implemented circumferential bus rapid transit (BRT) corridor. Silver Line BRT service began in 2002 with conversion of existing bus service on Washington Street, and was expanded in 2004–05 with new routes serving the Waterfront Tunnel in the Seaport District. A second Silver Line service using the Washington Street corridor was added in 2009, and service from the Waterfront Tunnel to began in 2018 with a new surface busway in Chelsea. The BERy and MTA operated overnight Owl service until 1960. From September 2001 to June 2005, the MBTA operated bus service on 17 routes (7 normal bus routes and 10 routes replicating subway lines) until 2:30am on Friday and Saturday nights. Similar service on the key routes was operated from March 2013 to March 2014. In 2017, the MBTA Board rejected a proposal to run all-night service on several routes with pulsed connections at a central hub. In 2022,