The Central Artery was the primary highway that coursed through the heart of Boston’s downtown. Long-standing as one of the most congested highways in the U.S., the Central Artery originally carried around 75,000 vehicles a day in the 1960s, but by the 1990s, over 200,000 vehicles jammed daily commutes.
The transformative Central Artery/Tunnel (CA/T) or “Big Dig” megaproject rerouted the Central Artery (I-93) into a 3.5-mile-long tunnel. The 4-lane Ted Williams Tunnel extends I-90 to Logan International Airport; the Leonard P. Zakim Bunker Hill Memorial Bridge over the Charles River; and the Rose Kennedy Greenway in the space vacated by the previous I-93 elevated roadway.
STV, in joint venture, provided civil, structural, mechanical, electrical, geotechnical, and utilities engineering, and managed all disciplines for the design-build program, which was recognized as the top engineering project in Massachusetts by the American Council of Engineering Companies of Massachusetts.
Located on I-93 beginning at Kneeland Street and extending to Congress Street in the heart of Boston, the northbound tunnel portion was the CA/T’s most technically complex and challenging section. It included the development of excavation support systems and underpinning for the historic Massachusetts Bay Transportation Authority (MBTA) South Station to allow mining beneath the station without interruption of service. The project created many green spaces, parks and public plazas, as well as a shoreline restoration along the Charles River and other stretches of the Boston Harborwalk.
12%
reduction in citywide carbon monoxide levels
3.5
mile-long tunnel
45
parks and public plazas created
