CAMBRIDGE- SUPERSTRUCTURE REPLACEMENT, C-01-031, US ROUTE 3/ROUTE 16/ROUTE 2 OVER MBTA REDLINE

This project includes replacement of the bridge superstructure which carries Alewife Brook Parkway, US Route 3, Route 16, and Route 2 over the MBTA Redline tunnel, increasing its design life and enhancing safety to all roadway users. The work consists of demolition of the existing superstructure in its entirety and its replacement using precast bridge units (PBUs), conducted in two stages to maintain vehicle access during construction. Sidewalks along the parkway (within the project limits) will be closed during construction and pedestrians will be detoured. The existing utilities over/attached to the bridge will be temporary relocated. Two-way traffic will be maintained over the bridge during majority of the construction, except over two inconsecutive long weekends at which time some detours will be needed. Similarly pedestrian and bicyclists access to the path directly below the bridge will be maintained, except during the same two long weekends. The proposed approach roadway work is limited in scope and is primarily to replace what are removed for/impacted by construction (e.g. sidewalk, guardrail). The area below the bridge that is primarily used by pedestrians and bicyclists is in poor conditions, thus will be resurfaced as a part of this work.