Speed through the tunnel is 30 mph (48 km/h) for passenger trains, 25 mph (40 km/h) for freight trains. Only continuous tunnels are included. Pipelines, even those that are buried, are excluded. The gradient is 2.2% on the west side from the town of Skykomish. Both uses are highly sensitive to gradients. List of Road Tunnels in USA, edited by Eugenio A. Merzagora. The tunnel has been the site of at least 6 … Largest Tunnels in the US Delaware Aqueduct is the longest tunnel in the world at 85 miles long and 13.5 feet wide. The 3.6-mile tunnel was opened in September 1974. Road Tunnels in United … The Both uses are highly sensitive to gradients. Ted Williams is one of the longest tunnels in the United States – at 1.6 miles. Name Location Length Expected … The speed limit in the tunnel is 40mph, and a toll of $3.50 is required to pass through (westbound only) when entering South Boston. This list of longest tunnels ranks tunnels that are at least 13 km (43,000 ft) long. This railroad tunnel is remnant of the abandoned coal mining town of Moonville, founded in 1856 and deserted in 1947. The longest tunnels have been constructed for water distribution, followed by tunnels for railways. The gradient in this tunnel is 1.565% (1:64), with the rise from west to east. This tunnel was opened in 1995, and is still open today. The longest tunnel in the world is the Delaware Aqueduct (85.1 miles) which … The longest underwater tunnel in the USA, and all of North America, is the Transbay Tube which takes BART rapid transit trains beneath the bay between San Francisco and Oakland, California. The longest tunnels have been constructed for water distribution, followed by tunnels for railways. Here are some of the longest tunnels in the US. Fort George Tunnel, IRT Broadway–Seventh Avenue Line (1 train), 2 miles of rock tunnel from 157th Street to Dyckman Street, the second-longest two-track tunnel in the country (after the Hoosac Tunnel) when completed in 1906. This tunnel is an extension of I-90, and is located in Boston, Massachusetts. World's longest railway tunnels under construction.