WILLIAMSTOWN — Work on the Main Street bridge that crosses the Green River has begun in earnest, affecting the flow of traffic on Route 2.
Crews have shifted the lanes to allow for work on the southern side on the span, where support structures are in place.
According to information provided by state Department of Transportation, the project calls for the removal of the existing bridge’s superstructure and substructure. Work will stretch into May 2026.
The bridge is scheduled to be replaced in stages, in an attempt to allow two lanes of travel as much as possible, although the road will likely be briefly closed five times (anticipated to be 24 hours or less) with traffic detoured over Cole Avenue.
The closing will be needed to allow for the erection of bridge beams on four occasions and during the initial curing of the concrete deck.
In addition to the removal stages, the work includes bridge reconstruction, roadway reconstruction, drainage modifications, pavement markings, landscaping and other tasks.
It happens to be at the confluence of a number of utilities, including electric, cable, and water/sewer lines, which took all last summer to relocate to make room for the work.
Beyond that, it is a complicated total replacement project. Among other things, that means completely removing the decks and installing support piers, the bases of which need to be sunk into the ground beneath the river bed. To do that, they have to redirect the flow of the river.
All this has to be done while still allowing traffic to flow. So they have to do it in sections, one step at a time.
A retaining wall will be constructed at the northwest corner, with new support piers installed.
MassDOT spokesperson Judith Reardon Riley said a temporary pedestrian bridge will be installed on the south side of the span to ensure that people can continue to cross during construction.
Northern Construction is the prime contractor. The bid price for the project was $5.2 million.
“On average, there have been about four workers on site with potentially 15 workers on site for major operations such as concrete deck placements,” Riley said by email.
The existing bridge was built in 1939. Initially the scope of the project was a superstructure replacement. It became a full bridge replacement upon further examination.
The construction team will limit some traffic disruptions with night work and by reducing its activity during the morning and afternoon commutes.
According to information released by the engineering firm CME Associates in 2018, the bridge’s center pier likely will need to be replaced and require extensive work in the river.
The location poses challenges. There are overhead and underground utilities located on, over and around the bridge, including an electric substation, electric lines, telephone lines, cable lines, fiber-optic lines and water, sewer and gas infrastructure.
Bronze medallions located on the existing end posts and the existing flower pots will be incorporated into the new structure.