I-90/1A Interchange Project

Location: Boston, Massachussetts
Contract: CA/T C08A1
Contract Value: $267,541,548
Project Dates: January 2006 – June 2007


This project was a combination of two contracts; the Central Artery Tunnel Project’s (CA/T) Contract C08A1 and the Massachusetts Bay Transportation Authority’s (MBTA) Contract S12CN01.

The work of C08A1 consisted of the construction of at-grade and elevated highways which link Route I-90 (Ted Williams Tunnel), Route 1A, the entrance/egress roads at Boston’s Logan Airport and the MBTA’s Airport Station.

The newly constructed elevated highways cross surface roads, sidewalks, bus platforms, train tracks, and a subway station.  The I-90 Eastbound and Westbound viaducts cross over the MBTA’s Blue Line tracks and Route 1A Northbound.  The Route E1A Northbound and Southbound viaducts cross over the MBTA’s Airport Station, Blue Line tracks, the surface road in front of the station and the bus platform and canopies.

A major component of the project was the implementation of a comprehensive staging and detour plan so that the flow of traffic in and out of the airport was not interrupted; all roadways, tunnels, and rail lines were maintained open to the public during construction.
Included in this work were the design and construction of temporary at-grade and elevated roadways, lighting and drainage.  Alterations and upgrades to existing steel viaducts, including structural steel modifications and painting were also major project elements.

The contract also included construction of a stormwater pump station and extensive rehabilitation of existing utilities.  Installation of new drainage / utility lines included 500 feet of 108” reinforced concrete pipe (RCP), 800 feet of 96” RCP, 600 feet of 54” RCP, and 575 feet of 48” RCP.

Improvements to an existing park and construction of a new park, traffic signalization, an Integrated Project Communication System (IPCS), and signing and pavement markings, were included.  Removal of contaminated material, demolition of steel viaducts, reinforced concrete ramp structures, billboards, and several minor buildings were also required.