Officials expect the $3.9 billion Hampton Roads Bridge-Tunnel expansion project to be substantially complete by February 2027, after years of boring underwater tunnels and widening lanes on land.

The 430-ft-long, 4,700-ton variable density tunnel boring machine began its round trip beneath the harbor in April 2023, completing the first tube just under one year later. The $3.9-billion expansion ...

Over 200 underwater bridge tunnels exist for vehicular traffic around the world, providing connectivity between cities. Once constructed, however, these tunnels are difficult to monitor and maintain, ...