Dorchester Branch service returned in 1979 as a Southwest Corridor construction bypass and became permanent as the Fairmount Line in 1987.

Readville station is located at the crossing of two rail lines: the north–south Northeast Corridor and the northeast-southwest Dorchester Branch (Midland Division).

In 2016, the MBTA considered the addition of elevators to supplement the ramps and add an accessible route to the Milton Street parking lot; however, this was not pursued.

[4] Readville 1-Yard is an active CSX freight yard located south of the station, connecting the Dorchester Branch to the Northeast Corridor.

Construction began in late 1832, and the B&P opened from Park Square, Boston to Sprague Mansion in Dedham Low Plain (just south of the modern station) on June 4, 1834.

[8]: 43  The Midland Branch was intermittently operated over the next decade due to a lawsuit about grade crossings and financial issues of the parent railroad.

In 1896, the New Haven eliminated Readville short turns in favor of higher-frequency service north of Forest Hills on its newly elevated mainline.

[18] In September 1899, most service from the southwest on the Midland Branch was routed onto the Providence Division at Readville, allowing use of express tracks and the new Back Bay station.

[8]: 45 In 1900, the New Haven began construction of Readville Shops, a large coach repair yard complex located in the wedge-shaped space between the Midland and Dedham lines.

[21][22] The powerhouse of the shops was designed to also power a planned electric suburban service, which was to run from Dedham to the new South Station on two routes via Readville and via West Roxbury to compete with the new Washington Street Elevated.

[25] Rail service in the Boston area peaked in the early 20th century and began to decline after World War 1.

[13]: 180  Readville–Boston service on the Midland Branch (four daily round trips) was discontinued on July 18, 1938, as part of the 88 stations case; it was restored in 1940, but ended again on Mar 12, 1944.

[26] By the early 1960s, Readville was served only by peak-hour peak-direction trains on the Providence and Blackstone lines, plus the single weekday Dedham round trip.

[3] On April 24, 1966, the MBTA began subsidizing some New Haven commuter service, including the Dedham and Blackstone lines (the latter cut back to Franklin that day).

[3] The MBTA purchased most of the New Haven's former commuter lines, including the Providence, Franklin, and abandoned Dedham routes, from Penn Central on 27, 1973.

[3] Construction of the Southwest Corridor necessitated closure of the main line between Back Bay and Forest Hills.

[3] (Until 2004, a small number of Providence/Stoughton Line trains diverted to the Dorchester Branch at Readville without stopping at the station; such a diversion has also been used during service disruptions on the Northeast Corridor.

The span was replaced with a prebuilt bridge in two weekends with minimal impact to Amtrak and MBTA service on the Corridor, with the old abutments left in place as retaining walls.

A 1999 proposal to expand the 12-track facility by 8-10 tracks (as Amtrak's Northend Electrification Project reduced MBTA midday storage at Southampton Street Yard) was opposed by then-mayor Thomas Menino, who lived several blocks away.

[46] In 1989–90, while analyzing 5-Yard for potential use as a commuter rail facility, the MBTA discovered high levels of environmental contamination including lead and petroleum hydrocarbons in the soil.

[7] In October 2001, Massachusetts Attorney General Thomas F. Reilly sued the MBTA for failing to decontaminate the site.

[48][49][50] In March 2012, the MBTA announced that the contamination had been fully removed, and revealed plans to place solar panels in the west part of 5-Yard.

[53] In July 2013, MassDOT (the MBTA's parent agency) announced that construction would not begin until at least 2014 due to a state solar program reaching capacity earlier than expected.

[55] Readville 5-Yard was considered for use as a midday layover yard in 2013 as part of South Station Expansion planning, but was rejected because the MBTA had committed to Boston that the site could be used for development.

[60] The 1966 Program for Mass Transportation recommended a bifurcated Orange Line, with one branch to West Roxbury or Hersey and another to Readville or Route 128 via Hyde Park.

[61] Various reports over the next two decades continued to recommend various combinations of the extensions; however, due to cost, the 1987 relocation of the Orange Line to the Southwest Corridor was terminated at Forest Hills.

[62] The 2004 Program for Mass Transportation included an Orange Line extension to Route 128, with intermediate stops at Mount Hope, Hyde Park, and Readville at a cost of $342.8 million.

The extension was listed as low priority due to environmental issues with crossing the wetlands south of Readville, and because the corridor already had commuter rail service.