An extradosed bridge—often described as a hybrid of a cable-stayed and a box-girder structure—now stretches across the Quinnipiac River in New Haven, Conn., as the crown jewel of a $2-billion, 7.2-mile-long Interstate 95 improvement program. Project officials say the extradosed design, rare in the United States, offered a number of space- and cost-saving advantages for this particular location while satisfying the public desire for a signature bridge.
The Connecticut Dept. of Transportation launched its I-95 New Haven Harbor Crossing Corridor Improvement Program in 2000. ConnDOT is reconstructing the I-91/Route 34 interchange, adding a new 1,700-ft-long steel-girder flyover into New Haven and a new commuter rail station. The old steel-plate girder Q Bridge, built in the 1950s for 40,000 daily vehicles, now carries 140,000.