BRAINtree station flyover rehabilitation

Steere provided bridge, highway, drainage, and maintenance and protection of traffic design for the $3 million rehabilitation of the Braintree Station Flyover in Braintree, MA. The Flyover is approximately 1200’ long and includes three (3) bridges and approach roadways that provide vehicular access to the MBTA Braintree Red Line Station and Parking Garage.

The rehabilitation design was performed on an accelerated 4-month schedule and utilized a combination of preservation techniques, element replacement, and safety feature upgrades to extend the useful service life of the flyover ramp. 

Bridge No. B-21-065 (4U6) is a single span bridge over Grossman Avenue consisting of prestressed concrete girders made composite with a reinforced concrete deck topped with a polymer modified concrete (PMC) overlay wearing surface. The rehabilitation included snow fence installation, deck joint replacement, PMC overlay repairs, deck and girder repairs, abutment repairs, and concrete sealing.

Bridge No. B-21-023 (8NX) is a single span bridge over Union Street consisting of built-up riveted steel plate girders made composite with a reinforced concrete deck topped with a full depth pavement section. In addition to the Flyover Ramp, the bridge carries five (5) railroad tracks and a sidewalk for pedestrian access to Braintree Station. The rehabilitation included snow fence installation, barrier repairs, full depth pavement reconstruction, deck underdrain installation including tie-in to existing drainage system, substructure repairs, and concrete sealing.

Bridge No. B-21-011 (867) is a four (4) span viaduct over the Station Access Road consisting of rolled steel beams made composite with a reinforced concrete deck topped with a PMC overlay wearing surface. The northerly span is bifurcated with splayed beams to provide ramp access to the parking garage. The rehabilitation included the replacement of the bridge deck including barrier upgrades, snow fence installation, deck joint replacement, cleaning and painting of steel, isolated repair and strengthening of steel cross beams, and replacement of the bridge drainage system.  

Approach roadways typically exhibited areas of failing pavement, isolated pooling of water, and missing curbing. The project rehabilitated the roadways through a combination of mill and overlay and full depth pavement reconstruction. Low points were identified and regraded to facilitate proper drainage. Curbing and wheel chair ramps were replaced to conform to current MassDOT standards.

Location: Braintree, MA

Owner: Massachusetts Bay Transportation Authority (MBTA)

Timeline: Design Completed in 2022; Construction Completed in 2024