Route 15 (MBTA)

Route 15 is a local bus route in Boston, Massachusetts, United States, operated by the Massachusetts Bay Transportation Authority (MBTA) as part of MBTA bus service. It operates between Ruggles station and Fields Corner station via Nubian station and Uphams Corner. It is among the highest-ridership routes on the system, with service every 15 minutes or less during all operating hours. Route 17 is a less-frequent route that operates between Andrew station and Fields Corner station. Between Fields Corner and Uphams Corner, it follows the same routing as route 15.

Most portions of routes 15 and 17 originated as horsecar lines built or acquired by the Metropolitan Railroad between 1856 and 1873. The West End Street Railway purchased and merged all the horse railroads in the Boston area in 1887. It electrified the Dudley Street and Meeting House Hill lines in 1893–94. Its successor, the Boston Elevated Railway (BERy), opened an extension of the Meeting House Hill line to Fields Corner in 1899 and re-opened a line to Andrew Square in 1901. The Washington Street Elevated opened in 1901, with some streetcar service terminated at Dudley Street Terminal rather than running to downtown Boston.

Extensions of the Cambridge–Dorchester Line to Broadway in 1917, Andrew in 1918, and Fields Corner in 1927 resulted in further changes. By the 1940s, service on Dudley Street consisted of a Dudley–Uphams Corner streetcar line (route 15), while service on Meeting House Hill consisted of an Andrew–Fields Corner streetcar line (route 17) and a belt line bus. The Metropolitan Transit Authority (MTA) replaced the BERy in 1947. It converted route 15 to trolleybuses in 1948 and route 17 in 1949. Routes 15 and 17 were converted to bus in 1962.

The Massachusetts Bay Transportation Authority (MBTA) replaced the MTA in 1964. Route 15 was extended to Ruggles in 1987 when the Southwest Corridor replaced the elevated. Weekend service was extended to Fields Corner in 2007. A number of stops on the route were closed in 2013 to reduce travel times. A 2018–19 MBTA review of its bus system found that routes 15 and 17 suffered from poor reliability. As part of systemwide network changes, all route 15 service was extended to Fields Corner in 2025.