Massachusetts
- Tunnels connected to the Big Dig project in Boston:
- Callahan Tunnel under Boston Harbor
- City Square Tunnel in the neighborhood of Charlestown
- Dewey Square Tunnel, Interstate 93 southbound
- Sumner Tunnel under Boston Harbor
- Ted Williams Tunnel under Boston Harbor, Massachusetts Turnpike
- Thomas P. O'Neill Jr. Tunnel, portions Interstate 93 in coordination with the Dewey Square Tunnel
- Massachusetts Bay Transportation Authority tunnels:
- Cambridge Tunnel, now part of the MBTA Red Line
- Dorchester Tunnel, now part of the MBTA Red Line
- East Boston Tunnel, now part of the MBTA Blue Line
- Harvard Bus Tunnel
- MBTA Orange Line Haymarket North and Southwest Corridor extensions are partially tunneled
- MBTA Silver Line bus tunnel
- Tremont Street Subway, now part of the MBTA Green Line
- Washington Street Tunnel, now the core of the MBTA Orange Line
- Hoosac Tunnel, Boston and Maine Railroad, through the Berkshire Mountains near North Adams
- Prudential Center Complex tunnel, Massachusetts Turnpike
- State Line Tunnel, CSX Railroad, near Stockbridge
Read more about this topic: List Of Tunnels In The United States