Massachusetts Department of Transportation Route 146 Interchange Reconstruction

The existing interchange, which was designed in the 1950s’, could no longer handle the increased volume of traffic traveling through the area, resulting in undesirable and unsafe conditions. The goal of the project was to improve safety and mobility for all users of this interchange.

This complex project widened Route 146 to provide acceleration and deceleration lanes and raised the profile of the bridge to increase truck clearance. Work involved the replacement of the steel stringer bridge that carries Route 146 over West Main Street. The bridge was replaced in three phases in order to maintain two lanes in each direction of Route 146 traffic at all times for this heavily traveled highway.

Of most interest to the community, was the design and construction of two roundabouts at this interchange. The single-lane roundabout replaced a very confusing, unconventional, unsignalized intersection where traffic calming and improved safety were needed. The mini roundabout replaced a signalized intersection in order to improve operations while providing a gateway treatment for the community.

In addition to improving traffic flow, the proposed design also improves access for pedestrians and bicyclists through the intersections. Other service elements included survey, environmental permitting, traffic engineering, traffic simulation, stormwater management design, construction staging, ROW/layout services, roadway lighting, landscaping, improved ADA-compliant pedestrian access, and bicycle accommodations.