Commonwealth Avenue is one of the primary access points to Boston for East-West bound traffic. This broad avenue proceeds directly from the heart of downtown Boston to Packard’s Corner in Boston’s Allston neighborhood. It carries traffic and the MBTA subway line, the Green Line, parallel to other main transit routes such as Storrow Drive and above others, namely Interstate 90 and the MBTA commuter rail. The Commonwealth Avenue bridge site itself borders directly on Boston University’s main urban campus and further carries large numbers of MBTA buses in and out of the Allston area.
The bridge superstructure was constructed in 1965. The project was estimated to cost $81.8 million and was designed to use Accelerated Bridge Construction methods in order to mitigate long term traffic impacts at this major intersection. The bridge was demolished and reconstructed in two short intensive efforts calling for crews to work around the clock for 15.5 days. While the full closure of the bridge and lane closure of I-90 below the bridge caused interruptions to the area’s usual traffic flow, the intensive, tireless work of construction crews meant that this large-scale project came to fruition in a matter of weeks rather than years.
The new Commonwealth Avenue Bridge represents a large stride for multimodal road use in the city of Boston. Roadway improvements include dedicated bike lanes, raised curbs, improved drainage utilities, traffic islands, new traffic lights, and improved signal timing. Bus and rail access were also improved with the inclusion of new stopping bays for buses and increased visibility and sidewalk access to the MBTA Green Line. Additionally, new improvements to this bridge and surrounding roadways aim to increase accessibility for people with disabilities using more frequent ramps and road crossings as well as widened platforms.