Routes 20, 117 traffic to be impacted by Waltham project

A new development just over the town line in Waltham is likely to have an impact in Weston.

The city and Boston Properties, a Boston-based development company, have engaged in a public-private partnership to reconstruct and extend Green Street – an 850-foot dead-end road off Route 117 – down to the Route 20/Interstate 95 interchange. The expansion will connect the two main arterial state roads linking Weston to Waltham, according to a contract provided by the Executive Office of Economic Development.

Weston residents will see future traffic impacts on both state routes as housing developments are planned in the area for both communities, with up to 1,500 units in Waltham.

Waltham Traffic Engineer Michael Garvin said the project will redistribute traffic on roads east of the highway, such as Route 20 and Stow Street, to west of the highway on Green Street.

“Of course, the reason the developers are willing to invest the funds to build the new connection is so they are then able to develop more on their property,” Garvin said. “This added development will increase traffic overall on all the roads (including in Weston), but by redistributing the traffic onto Green Street, the roads should be able to accommodate the increased traffic volumes.”

The $30 million project is currently partially funded by approximately $7.5 million in state grant funding and $15 million committed by Boston Properties. Waltham has submitted an application for an additional $7.5 million in grant funding, which is under review by the state.

In its entirety, the construction will realign Green Street with Bear Hill Road in Waltham, add a shared-use path between Routes 117 and 20, implement utility and stormwater infrastructure and create two new traffic lights on Route 20, one at the new Green Street/Route 128 southbound on-ramp and one at Weston Street’s merge point just north of the overpass. Construction is expected to begin in August and is slated to finish in October 2028, according to the contract and grant application provided by the state.

Garvin noted some aspects of the project, including a new, wider bridge on Main Street/Route 117 and a northbound on-ramp from Route 117, will be built in later phases.

Alongside the new public road extension, Boston Properties and 1265 Main Street LLC have planned housing up to 1,500 housing units just over the town line. Boston Properties also has housing planned in Weston at 133 Boston Post Road, a development unlocked by the October 2025 adoption of the MBTA Communities Act zoning change. That Weston development could bring up to 480 housing units to the area if all three phases are completed.

“These improvements are part of a multi-phase series of transportation infrastructure projects, estimated at $89 million, that will transform connectivity in west Waltham to ensure that roadway networks support all travel modes, reduce congestion and can support the additional traffic resulting from additional housing stock in the area,” the state’s contract reads.

Weston Town Planner Imai Aiu said the Green Street Connector project was taken into consideration when the town was planning transit access to 133 Boston Post Road.

Boston Properties could not be reached for comment.

The Green Street Connector, as well as the planned housing developments, play into a long-range Massachusetts Bay Transportation Authority plan to relocate the Kendal Green station from its current location to the vicinity of Jones Road and Green Street.

“This hub would provide a central connection point between major roadways of Route 20, Route 128/I-95, the Commuter Rail Fitchburg Line and the planned future continuation of the Mass Central Rail Trail,” states a land-use and transportation study published by the Department of Transportation in 2023.

The report states that Kendal Green would be replaced with a new “I-95 urban rail station with direct connection” to the highway, and the project would close both Silver Hill and (the already indefinitely closed) Hastings stations.

Any possible relocation of Kendal Green is still in early planning phases – with no money appropriated – and the MBTA is still considering feasibility and design in partnership with Boston Properties, according to the MBTA.