The United States has some of the longest tunnels in the world. There are many different types of tunnels, such as vehicle road traffic, rail, and canal tunnels. The longest tunnels have been constructed for water distribution, followed by tunnels for railways. Both uses are highly sensitive to gradients.
The longest tunnel in the world is the Delaware Aqueduct (85.1 miles), the main water supply tunnel of New York City. In this article, we have collected the ten longest highway tunnels in the United States. Let’s see how many of them have you seen for yourself!?
10. Fort McHenry Tunnel, Maryland
The Fort McHenry Tunnel is a four-tube, immersed tunnel with two lanes each. It carries traffic on Interstate 95 underneath the Baltimore Harbor. Built between 1980 and 1985, the Fort McHenry Tunnel cost $750 million to build. This project required over 3.5 million cubic yards of soil excavation, over 900,000 cubic yards of concrete, and over 100 million structural steel pounds. It is the widest underwater tunnel in the world.
9. Hampton Roads Bridge-Tunnel, Virginia
The Hampton Roads Tunnel, built between 1957 and 1976, is the oldest tunnel on I-64 in Hampton Roads. The first two-lane tunnel opened in 1957, and a second opened in 1976. It connects Hampton and Newport News to Norfolk and Virginia Beach. The tunnel is used by nearly three million vehicles each month. It carries more than 100,000 vehicles a day during the tourist season.
8. Baltimore Harbor Tunnel, Maryland
The Baltimore Harbor Tunnel is a pair of immersed tunnels stretching from the south shore of the Patapsco River to the north shore near Dundalk. The two-lane tunnels are 1.45 mi. 7,650 feet (2.3 km) long, carrying Interstate 895—the Harbor Tunnel Thruway.
7. Thomas O’Neill Jr. Tunnel, Massachusetts
The Thomas O’Neill Jr. Tunnel is a highway tunnel built as part of the Big Dig in Boston, Massachusetts. The tunnel is named for Tip O’Neill, former Speaker of the United States House of Representatives. Originally built for 75,000 vehicles a day, the expressway carried 200,000 vehicles a day by the early 1990s. Within a year of opening, a large leak backed up traffic for miles. In 2007, 500 leaks needed to be repaired. Corrosion of the tunnel light fixtures also became a problem, which was evidenced in 2011 when a light fixture crashed down onto the roadway.
6. Lincoln Tunnel, New York
The Lincoln Tunnel is one of two automobile tunnels built under the Hudson River, the other being the Holland Tunnel. Connecting Weehawken, New Jersey, and Midtown Manhattan in New York City, the Lincoln Tunnel is approximately 1.5-mile-long (2,4 km). Comprised of three tunnels, it was built over 20 years. In 2016, the Lincoln Tunnel carried a daily average of approximately 52,632 motor vehicles (or 19,210,919 for the year). The tunnel is considered to be one of the most high-risk terrorist target sites in the United States.
5. The Holland Tunnel, New Jersey & New York
The Holland Tunnel connects Canal Street in Manhattan with 12th and 14th streets in Jersey City, NJ. This highway tunnel, running under the Hudson River, is the first vehicular crossing under the river and is considered an outstanding engineering achievement. For centuries, passage across the lower Hudson River was possible only by ferry. As a tribute, it bears the name of its first chief engineer, Clifford M. Holland.
4. Eisenhower Memorial Tunnel, Colorado
The Eisenhower Memorial Tunnel near Denver, Colorado, is 1.693 mi (2.72 km) long. With a maximum elevation of 11,158 ft (3401 m) above sea level, it is one of the world’s highest road tunnels and the longest mountain tunnel. The four-lane vehicular tunnel carries Interstate 70 under the Rocky Mountains. The construction on the first bore of the tunnel was started in 1968, and though the project was supposed to take three years, it was not opened to traffic until 1973.
3. Brooklyn–Battery Tunnel, New York
The Brooklyn- Battery Tunnel in New York City, or as officially known the Hugh L. Carey Tunnel, is a toll-tunnel that connects Red Hook in Brooklyn with Battery Park City in Manhattan. With a length of 9,117 feet (2.7 km), it is the longest continuous underwater vehicular tunnel in North America. The tunnel’s construction began in 1940 with a groundbreaking ceremony attended by President Franklin D. Roosevelt and was opened to traffic in 1950. The tunnel was officially renamed after former New York Governor Hugh Carey in 2010.
2. Anton Anderson Memorial Tunnel, Alaska
The Anton Anderson Tunnel, also known as the Whittier tunnel or the Portage tunnel, is a road and railway tunnel through Maynard Mountain in Alaska. It links the Seward Highway with Whittier and is the only land access to the town. At 13,300 feet (4 km), it is the second-longest highway tunnel and the longest combined rail and highway tunnel in North America. The Whittier tunnel’s interior is exposed rock and contains several “safe-houses,” which are small buildings used in case of severe earthquakes, vehicle fires, or other emergencies. The tunnel’s entrance portals are designed to withstand the force of an avalanche. The tunnel was named after Anton Anderson, the chief engineer for the project that brought rail access to Whittier.
1. Ted Williams Tunnel + I90 Extension, Massachusetts
With a length of 1.6 miles (2.6 km), the Ted Williams Tunnel with the I90 extension (1.6 km, opened in 2003) is the longest tunnel in the US. The Ted Williams Tunnel interface in East Boston between the land-based approach and the underwater portion is 90 feet below Boston Harbor’s surface, the deepest such connection in North America. This highway tunnel was constructed between 1991 and 1995, and it is named after the former Boston Red Sox baseball player and U.S. Marine air corps veteran Ted Williams.