Mattapan Line

Mattapan Line

Company type	Light rail transit line
Industry	Public transportation
Founded	August 26, 1929 (1929-08-26)
Headquarters	Boston, Massachusetts , United States
Area served	Boston and Milton, Massachusetts
Owner	Massachusetts Bay Transportation Authority (MBTA)
Parent	Massachusetts Bay Transportation Authority (MBTA)

Mattapan Line

The Mattapan Line, also referred to as the Mattapan Trolley or historically the Ashmont–Mattapan High-Speed Line, is a light rail route operated by the MBTA that is partly grade-separated. It serves the communities of Boston and Milton, Massachusetts and began operations on August 26, 1929, after converting a former commuter rail corridor. This line exclusively runs PCC streetcars dating back to the 1940s. Passengers transfer at Ashmont station to connect with the remainder of the Red Line heavy rail rapid transit system.

Dedicated solely to streetcar operation, the route includes only two public grade crossings. Stations feature low-level platforms, with all but Valley Road outfitted with wheelchair ramps or lifts to ensure accessibility. Unlike many heritage streetcar lines, the Mattapan Line functions as an integral component of the MBTA’s active transit network rather than serving as a tourist attraction. A comprehensive modernization initiative is in progress to rebuild the line for use with contemporary light rail vehicles.

Commuter Rail Origins

The Dorchester and Milton Branch Railroad commenced service in December 1847, running from Neponset on the Old Colony Railroad main line to Mattapan station in Dorchester, passing through Milton Mills (later known as Milton Lower Mills, then simply Milton). The Old Colony Railroad immediately leased this route as its Milton branch. In 1872, the Old Colony constructed the Shawmut Branch Railroad, connecting Harrison Square to Milton Lower Mills via Peabody Square. Following this development, most passenger traffic to Mattapan shifted east of Milton onto this new branch, which served more densely populated urban neighborhoods. The Old Colony Railroad and its branches were acquired by the New York, New Haven and Hartford Railroad in 1893.

During the early 1910s, the Boston Elevated Railway (BERy) proposed extending its rapid transit Cambridge–Dorchester line southward from Andrew to Codman Square, running parallel to New Haven’s Shawmut branch and Midland Division. By the end of that decade, however, BERy’s electrified streetcar system had significantly reduced ridership on New Haven’s lines. Around 1920, BERy, New Haven, and the Boston Transit Commission reached an agreement on the Dorchester Circuit Plan: a two-way rapid transit loop extending south from Andrew along the Old Colony main line, incorporating Shawmut and Milton branches to Mattapan, linking with the Midland Division through tunnels, and returning back to Andrew.

Conversion to Rapid Transit

Although the Midland Branch served more densely populated areas, real estate interests favored extending service via the Shawmut branch. Approval for constructing a rapid transit extension to Mattapan through Shawmut was granted on March 23, 1923.

Steam-powered trains ceased operation in 1927 when the line closed for two years to facilitate conversion for streetcar use. Full subway service was considered prohibitively expensive for BERy. The segment between Ashmont and Milton opened on August 26, 1929; service extended from Milton to Mattapan on December 21, 1929. Additional infill stations at Capen Street and Butler were inaugurated in 1930 and 1931 respectively.

In 1966, this route was designated as part of the Red Line; prior to that it was known as route 28 Mattapan–Ashmont. On March 18, 1968, flooding disrupted service temporarily; operations resumed by March 21. In January 1981, due to financial constraints, MBTA proposed closing the line entirely but ultimately decided against it. The Mattapan Line along with the Ashmont branch underwent closure from June 20, 1981 to January 16, 1982 for track and tunnel maintenance.

The longest interruption occurred between June 24, 2006 and December 22, 2007 when shuttle buses replaced trolley service. During this period Ashmont station received a new elevated loop; Mattapan station’s canopy was replaced; intermediate stations were rebuilt with all but Valley Road made accessible. Service was again suspended for track work from October 14–29, 2023.

In 2019, MBTA initiated the Mattapan Line Transformation project aimed at replacing aging PCC trolleys with modern light rail vehicles (LRVs), reconstructing all eight stations, upgrading tracks and signaling systems, repairing bridges, and enhancing operations during snowstorms. Existing PCC cars are undergoing rehabilitation to extend their operational lifespan until LRVs are introduced. By 2023 design efforts had reached approximately 15% completion; as part of these upgrades, the Ashmont loop constructed in 2007 will be removed.

Route

This transit line runs exclusively within the city of Boston, with a significant portion of its southern segment traversing northern Milton. It traces the former corridors of two Old Colony Railroad branches that provided commuter rail service until the 1920s. The alignment closely follows the course of the Neponset River, crossing it twice along its path. Owned by the MBTA, the line features only two at-grade crossings throughout its entire length. Between the Cedar Grove and Butler stops, the route passes through Cedar Grove Cemetery.

As of , trains operate at six-minute intervals during weekday rush periods and run every 12 to 13 minutes during off-peak hours.

Station listing

Location	Station	Opened	Notes and connections
Dorchester, Boston	Disabled access REDIRECT Template:Boston transportation system	August 26, 1929	Template:Ric: Template:Ric Template:Ric: Template:MBTA bus links Template:Bus icon BAT: Template:MBTA other buses
	Disabled access REDIRECT Template:Boston transportation system
	Disabled access REDIRECT Template:Boston transportation system	October 7, 1931
Milton	Disabled access REDIRECT Template:Boston transportation system	August 26, 1929	Template:Ric: Template:MBTA bus links
	Disabled access REDIRECT Template:Boston transportation system	December 21, 1929	Template:Ric: Template:MBTA bus links Template:Bus icon BAT: Template:MBTA other buses
	REDIRECT Template:Boston transportation system
	Disabled access REDIRECT Template:Boston transportation system	September 1930
Mattapan, Boston	Disabled access REDIRECT Template:Boston transportation system	December 21, 1929	Template:Ric: Template:MBTA bus links

Accidents

On March 20, 1979, a collision involving three trolleys occurred between Central Avenue and Valley Road stations after two vehicles halted to avoid a police cruiser stuck on the tracks; a third trolley was unable to stop due to limited visibility around a curve. Although injuries were reported, no fatalities resulted from this accident.

Supported by funding from the American Recovery and Reinvestment Act of 2009, the MBTA trialed a collision avoidance technology utilizing radar and audio alerts to warn operators of obstacles ahead. Comparable to positive train control, this system was capable of halting trains automatically if drivers did not react. Following several collisions, there were considerations to implement this technology on the Green Line as well.

On November 26, 2014, an out-of-service streetcar collided with an active trolley near Cedar Grove station, resulting in seven passenger injuries.

A crash between two operational streetcars on December 29, 2017 caused injuries to seventeen individuals and was attributed to operator error. This incident reduced the number of functioning streetcars on the line to five.

Rolling stock

The rolling stock primarily features refurbished PCC streetcars, which were once shared with the Green Line. Due to infrastructure constraints originally designed for 1920s streetcars, only these lighter historic vehicles can operate on the line, as modern Green Line cars are incompatible. For snow removal, the MBTA employs a jet engine-driven snowblower known as "Snowzilla," consuming approximately of jet fuel per operation. Standard trains are unsuitable for snow clearing because their PCC traction motors are vulnerable to short circuits.

The existing fleet consists of "Wartime" PCCs manufactured by Pullman-Standard during 1945–46, continuously serving Boston since that time and dedicated to the Mattapan Line from 1955 onward. These cars underwent comprehensive rebuilds systemwide between 1978–83 and again from 1999–2005, with the latter refurbishment restoring their original bright orange and cream paint scheme instead of the Green Line livery. The vehicles sport a distinctive MBTA logo reminiscent of the Metropolitan Transit Authority period. Air conditioning was installed in 2008.

Although the MBTA has proposed replacing the PCC fleet with modern trolleys or buses multiple times, significant community resistance has prevented such changes. The FY2017-FY2021 Capital Investment Plan dedicated $9 million for the line, including $3.7 million earmarked for maintaining PCC cars and $5 million allocated toward possible alternative service options. In 2017, a $7.9 million modernization project commenced to upgrade propulsion systems; however, power irregularities caused damage to four vehicles by early 2018. Repair efforts announced in February 2018 aimed to extend the operational lifespan of the trolleys by seven to eight years, with refurbished cars reentering service beginning March 2022.

In 2018, the MBTA reconsidered options such as additional PCC refurbishments, procuring new replica streetcars, or converting the corridor into a busway. Community stakeholders have consistently favored maintaining rail service. By January 2019, transferring Type 9 LRVs from the Green Line to replace the PCC fleet had become the most practical solution. , plans remain in place to substitute PCC streetcars with Type 9 LRVs.

Fleet

The Mattapan Line operates a fleet of ten PCC streetcars, six of which are currently active. Of these active vehicles, three have been rebuilt.

Car #	Image	Status
3087		Template:Active
3230		Reserved for truck maintenance
3234		Template:Active, Rebuilt
3238		Undergoing truck maintenance and rebuild
3254		Undergoing truck maintenance and rebuild
3260		Template:Active, Rear section reconstructed following a collision in 2017
3262		Severely damaged beyond repair; rear section used to repair car 3260; scheduled for scrapping
3263		Template:Active
3265		Template:Active, Rebuilt
3268		Template:Active