complex of trestles, man-made islands, tunnels, and bridges that runs across the entrance to Chesapeake Bay, providing a vehicular roadway between the Norfolk–Hampton Roads area (southwest) and Cape Charles at the tip of the Delmarva Peninsula (northeast). It was begun in 1958 and completed in 1964. The bridge-tunnel complex is 17.6 miles (28 km) long from shore to shore and consists mostly of low trestle bridges carrying a two-lane highway. Because of the importance of shipping in the bay, the crossing was sunk deep beneath the main shipping channels in tunnels at two points, each tunnel being more than a mile long. Four man-made islands, constructed in water averaging 40 feet (12 m) in depth, provide portals by which the roadway enters the tunnels. Near the north end of the bridge-tunnel complex, flanking Fisherman Island off Cape Charles, two high-clearance bridges provide part of the crossing.