The 8 Largest Bridges in the United States

Written by Nilani Thiyagarajah
Updated: October 24, 2023
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Bridges are more important than a lot of people realize. They allow people to go places without having to deal with physical obstacles in the landscape. Basically, a bridge is a structure that spans one of these obstacles, whether it be a road, body of water, valley, or rail, without blocking whatever is underneath.

Some bridges are truly impressive in terms of size and length. They are not only structures that help people get from point A to point B but also true feats of engineering.

The largest bridges in the United States are based on length.

What would be considered the longest bridge in the United States? When we talk about the size of a bridge, it can be kind of tricky to decide what parameters to consider. However, for simplification, we’re going to look mostly at length. Without further ado, let’s take a look at the largest bridges in the United States!

8. General W.K. Wilson Jr. Bridge

General W.K. Wilson Jr. Bridge

General W.K. Wilson Jr. Bridge was built in 1980, and it crosses the Mobile-Tensaw River Delta.

©George Dodd III/

This bridge, which is 5.49 miles (8.84 kilometers) long, is located in Alabama. The weathering steel arches make it very visually distinctive and striking. The bridge is actually nicknamed the “Dolly Parton Bridge” because the red lights on its arches line up in curves that are reminiscent of her figure.

This bridge was built in 1980, and it crosses the Mobile-Tensaw River Delta. The bridge is a continuous stretch that carries four lanes of Interstate 65 through this area. Having opened in 1981, the bridge is named after General W.K. Wilson Jr., a local resident who was one of the first to communicate the need for such a bridge.

7. Seven Mile Bridge

Seven Mile Bridge

The Seven Mile Bridge crosses the Moser Channel and includes one bridge for vehicles and another for cyclists/pedestrians.


This Florida bridge, which is actually 6.7 miles (10.8 kilometers) long, goes over the Moser Channel in the Florida Keys. It connects Knight’s Key to Little Duck Key. Towards the middle of the bridge, there’s an arc that includes a 65-foot clearance so that boats can pass underneath the bridge.

The Seven Mile Bridge is part of the Overseas Highway, as well as part of US Highway 1. This may not be the longest bridge in the United States, but there are two bridges here–a modern one for vehicles and the older one for cyclists and pedestrians. The new bridge opened in 1982, while the older one was completed in 1912. That makes the Seven Mile Bridge not only very long but unique.

6. San Mateo-Hayward Bridge

San Mateo Hayward Bridge

The San Mateo-Hayward Bridge goes across the San Francisco Bay of California.


The San Mateo-Hayward Bridge goes across the San Francisco Bay of California, connecting the Eastern Gulf with the San Francisco Peninsula. The bridge is the longest bridge in California. Built in 1929, the length of the bridge is 7 miles or 11.2 kilometers.

California’s Department of Transportation and the State Highway Agency manages this bridge. It’s a part of State Highway 92, linking Interstate 880 with US Route 101.

5. I-10 Bonnet Carré Spillway Bridge

I-10 Bonnet Carré Spillway Bridge

The Bonnet Carré Spillway was first opened in 1937.

©Ray Devlin from New Orleans (for now), USA / CC BY 2.0 – License

The Bonnet Carré Spillway was opened in 1937 after a flood in 1927 that destroyed 27,000 square miles of the Lower Mississippi Valley. The bridge is in the Parish of St. Charles in Southeastern Louisiana. It connects New Orleans to Baton Rouge.

The bridge is 11 miles (17.7 kilometers) long and crosses the Bonnet Carré Spillway, Lake Pontchartrain, and LaBranche Wetlands.

The purpose of the Spillway is to divert excess water from the Mississippi River into Lake Pontchartrain in order to prevent future flooding. The Spillway Bridge is a concrete twin trestle bridge that guides Interstate 10 over the Spillway dike.

4. Chesapeake Bay Bridge-Tunnel

The Chesapeake Bay Bridge-Tunnel is 17.6 miles long and is partially made of underwater tunnels.


When it first opened in 1964, people dubbed the Chesapeake Bay Bridge-Tunnel “one of the Seven Engineering Wonders of the Modern World.” This Virginia bridge is 17.6 miles, or 28.3 kilometers, in length, and it crosses the Chesapeake Bay. The northbound part of the bridge opened in 1964, while the southbound part didn’t open until 1999.

What makes this bridge so unique is that it’s partially made up of tunnels on both sides. Each of these tunnels is about a mile long, goes underwater, and emerges on man-made islands. This allows boats and ships to travel over this passage.

This bridge includes four lanes for vehicles, and it’s the only connection between South Hampton Road and the Eastern Shore. It’s located at the mouth of Chesapeake Bay, and it includes a full-service restaurant, Chesapeake Grill. There are also restrooms and a gift shop on this bridge.

3. Atchafalaya Basin Bridge

Atchafalaya Basin Bridge

The Atchafalaya Basin Bridge is a twin bridge that goes between the cities of Baton Rouge and Lafayette in Louisiana.


Also known as the Louisiana Airborne Memorial Bridge, construction of this 18-mile (29-kilometer) bridge likely started in 1971. When it was first completed, this was actually the longest bridge in the United States.

Construction of the Atchafalaya Basin Bridge was challenging because of the variation and bogginess in the surrounding geography, as well as the likelihood of flooding. This bridge is a twin bridge that goes between the cities of Baton Rouge and Lafayette in Louisiana. It contains part of Interstate 10, which is a transcontinental interstate highway. It traverses Atchafalaya Basin, which is the largest swamp in the country.

The two bridges run parallel to one another for most of their course, but they join at Whiskey Bay when they cross the Pilot Canal.

2. Manchac Swamp Bridge

Manchac Swamp Bridge

The Manchac Swamp Bridge is about 23 miles long.

©Melanie Commander Thibodaux / CC BY 3.0 – License

The Manchac Swamp Bridge is 23 miles (37 kilometers) long. This bridge is one of the longest bridges over water in the world and the longest bridge on the interstate highway system. Many say that it is the longest toll-free bridge in the world. Built in 1979, it’s located in the state of Louisiana.

This bridge is part of US Route 51 and Interstate 55. It makes up about a third of the 66-mile highway. It’s a twin concrete trestle bridge located close to Lake Pontchartrain. The bridge itself goes over the Manchac Swamp.

Local legends say that the bridge and swamp are haunted by a voodoo princess and a Cajun werewolf. However, anyone who drives on this bridge shouldn’t be afraid, as long as they stay away from the alligators that live under the bridge.

1. Lake Pontchartrain Causeway

Lake Pontchartrain Causeway

The Lake Pontchartrain Causeway of Louisiana, 23.9 miles long, is the longest bridge in the United States.

©Mark Runde/

Extending 23.9 miles (38.4 kilometers), this bridge in Louisiana is the longest bridge in the United States. It was the longest bridge in the world from 1969 to 2011 until the construction of the Hong Kong-Zhuhai-Macao Bridge beat this long-standing record.

The bridge is actually two parallel bridges, supported by 9,500 concrete columns. It runs all the way across Lake Pontchartrain, making it possible for people to avoid a 90-minute drive around the entire lake to get to the other part of the city. The North End of the bridge is located in Mandeville, Louisiana, while the South End is located in Metairie, Louisiana.

Summary Of The 8 Largest Bridges In The United States

1Lake Pontchartrain Causeway23.9 miles
2Manchac Swamp Bridge23 miles
3Atchafalaya Basin Bridge18 miles
4Chesapeake Bay Bridge-Tunnel17.6 miles
5I-10 Bonnet Carré Spillway Bridge11 miles
6San Mateo-Hayward Bridge7 miles
7Seven Mile Bridge6.7 miles
8General W.K. Wilson Jr. Bridge5.49 miles

Other Bridges Worth a Mention:

Some people measure the Chesapeake Bay Bridge at only 4.3 miles long, but it would still make a list of 15 longest bridges in the United States. There are also two bridges that might bump the San Mateo-Hayward Bridge down two places on the list: the Louisiana Highway 1 Bridge and the Jubilee Parkway Bridge. Below is a list of other bridges of impressive length.

  • The Louisiana Highway 1 Bridge – 8.26 miles long in LaFourche Parish between Leeville and Port Fourchon, Louisiana. It is also known as the “Gateway to the Gulf Expressway.”
  • The Jubilee Parkway Bridge – 8 miles long in Spanish Forts, Baldwin County, Alabama. This bridge is actually two side-by-side bridges of two lanes each that cross Mobile Bay.
  • The Richmond-San Rafael Bridge – 5.5 miles long. Built in 1957 to cross the San Francisco and San Pablo Bays in California.
  • The Frank Davis “Naturally N’Awlins” Memorial Bridge is 5.4 miles long. Built in 2006, it also crosses Lake Pontchartrain in Louisiana.
  • The Virginia Dare Memorial Bridge – 5 miles long in North Carolina. Part of Highway 64, it is a four-lane bridge that crosses the Croatan Sound between Manns Harbor and Manteo on Roanoke Island.
  • The Bob Graham Sunshine Skyway Bridge – 4.1 miles long in Florida crosses Tampa Bay and connects St. Petersburg and Terra Ceia.

The photo featured at the top of this post is ©

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