The Southwest Corridor or Southwest Expressway was a project designed to bring an eight-lane highway into the City of Boston from a direction southwesterly of downtown. It was supposed to connect with Interstate 95 (I-95) at Route 128. As originally designed, it would have followed the right of way of the former Penn Central/New Haven Railroad mainline (current Amtrak Northeast Corridor) running from Readville, north through Roslindale, Forest Hills and Jamaica Plain, where it would have met the also-cancelled I-695 (Inner Belt Expressway). The 50-foot-wide (15 m) median for the uncompleted "Southwest Expressway" would have carried the southwest stretch of the MBTA Orange Line within it, replacing the Washington Street Elevated railway's 1901/1909-built elevated railbed. Another highway, the four-lane South End Bypass, was proposed to run along the railroad corridor between I-695 in Roxbury and I-90 near Back Bay.
History
Early railroad history
The Boston and Providence Railroad (B&P) was chartered on June 22, 1831 to build a rail line between its two namesake cities. Construction began in late 1832, and the B&P opened from Park Square, Boston to Canton in 1834. Through Roxbury and Jamaica Plain, the railroad largely followed the valley of Stony Brook. The remaining section of the B&P main line from Canton to Providence opened the following year with the completion of the Canton Viaduct. The B&P, like many early railroads, was primarily intended for intercity travel; the only intermediate stations north of Canton were at Dedham Plain (later called Readville) and Pierpont Village (later called Roxbury).
Two additional stations in Jamaica Plain were added in 1842: Jamaica Plain at Green Street, and Tollgate (later Forest Hills) where the line crossed the Norfolk and Bristol Turnpike. Additional stations on the inner part of the line were soon added, including stops at Boylston Street in Jamaica Plain and Heath Street in Roxbury. The B&P began regularly running Dedham Specials (which used the main line to Readville and the Dedham Branch to Dedham station) in June 1842, which made commuting from these intermediate stations possible. A second track from Boston to Roxbury was added in 1839 and extended to Readville in 1845.
Commuter traffic on the B&P – which had numbered just 320 daily passengers from the eight stations north of Readville in 1849 – rapidly expanded thereafter. The railroad cut sharply into the profits of the private turnpike; it became a free public road (Washington Street) south of Dedham in 1843, and north of Dedham in 1857. A third track from Boston to Readville was added in 1873-74. Around 1885, Forest Hills became the outer terminus for some short-turn commuter service. In 1888, the Old Colony Railroad bought the B&P.
Raising the railroad
Between the Boston terminal in Park Square and Forest Hills, the B&P mainline was at grade except for Hogg's Bridge, which carried Centre Street over the railroad. As traffic increased both on local streets (including horsecars and streetcars) and on the railroad, the numerous grade crossings became increasingly dangerous. (The danger was present even in the earliest years of the railroad; in 1846, a man was killed by a train at the crossing at Tollgate station.)
On June 21, 1890, the Massachusetts General Court passed An Act to Promote the Abolition of Grade Crossings, which allowed town officials or a railroad company to petition the state superior court to create an independent commission to determine whether a grade crossing could and should be eliminated. The costs of such eliminations were to be paid 65% by the railroad, not more than 10% by the town, and the remainder by the state. The small local cost provided towns incentive to petition for crossing eliminations to prevent public thoroughfares from being blocked by trains and to avoid deadly collisions. In July 1890, local politicians began planning for a grade crossing elimination project on the busy B&P mainline through Roxbury and Jamaica Plain. The B&P began property acquisition for the project in 1891. The General Court legislated the grade crossing elimination from Massachusetts Avenue to Blakemore Street on June 16, 1892. The cost allocation was changed from the 1890 bill: 55% by the railroad, 31.5% by the state, and 13.5% by the city.