Red Line (MBTA)

Red Line
A northbound Red Line train at Charles/MGH station in 2024
Overview
Owner	Massachusetts Bay Transportation Authority
Locale	Boston, Cambridge, Somerville, Braintree and Quincy, Massachusetts
Termini	Alewife (north) Ashmont and Braintree (south)
Stations	22
Service
Type	Rapid transit
System	MBTA subway
Services	2
Rolling stock	1500, 1600, 1700, 1800, 1900-series
Daily ridership	119,000 (2023)[1]
History
Opened	March 23, 1912
Technical
Line length	11.5 mi (18.5 km) Alewife–Ashmont 17.5 mi (28.2 km) Alewife–Braintree 22.5 mi (36.2 km) total
Track gauge	4 ft 8+1⁄2 in (1,435 mm) standard gauge
Electrification	Third rail, 600 V DC
Route map Show interactive map Legend Alewife Yard Alewife Davis Porter Stadium closed 1967 Eliot Street Yard Harvard/Brattle 1979-1983 Bennett Street Portal Harvard Harvard pre-1981 Harvard/Holyoke 1981-1983 Central Kendall/MIT Longfellow Bridge incline Charles River Charles/MGH Park Street Winter Street Concourse Downtown Crossing South Station I-90 Cabot Yard Broadway Andrew JFK/UMass I-93 / US 1 / Route 3 Savin Hill Fields Corner Shawmut Ashmont Codman Yard Ashmont–Mattapan High-Speed Line Ashmont–Mattapan High-Speed Line Cedar Grove Butler Milton Central Avenue Valley Road Capen Street Mattapan Yard Mattapan Neponset River North Quincy Wollaston Quincy Center Quincy Adams Greenbush Line Braintree Caddigan Yard Old Colony Lines This diagram: view talk edit Show route diagram map

The Red Line is a rapid transit line operated by the Massachusetts Bay Transportation Authority (MBTA) as part of the MBTA subway system. The line runs south and east underground from Alewife station in North Cambridge through Somerville and Cambridge, surfacing to cross the Longfellow Bridge then returning to tunnels under Downtown Boston. It continues underground through South Boston, splitting into two branches on the surface at JFK/UMass station. The Ashmont branch runs southwest through Dorchester to Ashmont station, where the connecting light rail Mattapan Line (shown as part of the Red Line on maps, but operated separately) continues to Mattapan station. The Braintree branch runs southeast through Quincy and Braintree to Braintree station.

The Red Line operates during normal MBTA service hours (all times except late nights) with six-car trains. The 218-car active fleet consists of three orders of cars built in 1969–70, 1987–89, and 1993–94. A 252-car order from CRRC is being built from 2019 to 2024. The Red Line is fully grade-separated; trains are driven by operators with automatic train control for safety. Cabot Yard in South Boston is used for heavy maintenance and storage; yards at Alewife, Ashmont, and Braintree are also used for storage. All 22 Red Line stations are fully accessible. Averaging 119,000 weekday passengers in 2023, the Red Line has the highest ridership of the MBTA subway lines.

The Boston Elevated Railway opened its Cambridge tunnel between Harvard and Park Street in 1912. It was extended south as the Dorchester Tunnel to Washington (now Downtown Crossing) in 1915, South Station in 1916, Broadway in 1917, and Andrew in 1918. The Dorchester extension added three stops to Fields Corner in 1927 and two more stops to Ashmont in 1928. Charles (now Charles/MGH) was added as an infill station in 1932. The newly formed MBTA assigned colors to its subway lines in 1965, with the Cambridge–Dorchester line becoming the Red Line. The MBTA added the three-station South Shore Line to Quincy Center in 1971; it was extended to Braintree in 1980, with Quincy Adams added as an infill in 1983. The Red Line Northwest Extension, originally planned to run to Arlington Heights or Route 128, opened to Davis in 1984 and Alewife in 1985.