Top 10 Longest Bridges in the United States

The United States is home to some of the most impressive and expansive bridges in the world, stretching across vast lakes, rivers, swamps, and bays. If you’re curious about the longest bridge in the United States, you’ll find plenty of awe-inspiring structures—some extending for dozens of miles!

This article showcases the 10 longest bridges in the United States based on total length, including causeways, interstates, and elevated expressways. These engineering marvels not only connect regions but also tell the story of American innovation and infrastructure at its finest.

Top 10 Longest Bridges in the United States

1. Lake Pontchartrain Causeway – Louisiana (23.87 miles)

The Lake Pontchartrain Causeway holds the title of the longest bridge in the US. Spanning nearly 24 miles, it connects Mandeville to Metairie, Louisiana, across Lake Pontchartrain. It’s also listed in the Guinness World Records as the longest continuous bridge over water.

2. Manchac Swamp Bridge – Louisiana (22.8 miles)

This dual-span bridge carries Interstate 55 and U.S. Route 51 through the wetlands of southeastern Louisiana. The Manchac Swamp Bridge is one of the longest toll-free bridges in the world and was built using concrete piles driven deep into the swamp floor.

3. Atchafalaya Basin Bridge – Louisiana (18.2 miles)

Also known as the Louisiana Airborne Memorial Bridge, this structure carries I-10 over the Atchafalaya Basin. It is the third longest bridge in the USA and plays a vital role in connecting Lafayette and Baton Rouge.

4. Chesapeake Bay Bridge–Tunnel – Virginia (17.6 miles)

Combining both bridges and tunnels, this marvel crosses the mouth of the Chesapeake Bay, linking Virginia’s eastern shore with the mainland. Its scenic views and engineering complexity make it one of the most unique and longest bridges in the United States.

5. Bonnet Carré Spillway Bridge – Louisiana (11 miles)

Carrying I-10 over a spillway designed to protect New Orleans from Mississippi River flooding, this bridge is one of the longest and most vital structures in the Southeast U.S.

6. Louisiana Highway 1 Bridge – Louisiana (8.26 miles)

Running over marshland to reach Port Fourchon, this elevated toll bridge is key to oil and gas operations in the Gulf of Mexico and is considered a critical energy corridor.

7. San Mateo–Hayward Bridge – California (7 miles)

Spanning the San Francisco Bay, this bridge connects the San Francisco Peninsula to the East Bay and is a vital route for commuters across Silicon Valley.

8. Seven Mile Bridge – Florida (6.79 miles)

One of the most iconic bridges in the U.S., the Seven Mile Bridge connects Knight’s Key to Little Duck Key in the Florida Keys. Its breathtaking ocean views make it a favorite among tourists and road trippers.

9. General W.K. Wilson Jr. Bridge – Alabama (6.08 miles)

Also called the Dolly Parton Bridge, this bridge spans the Mobile-Tensaw River Delta and is part of I-65. It plays an important role in freight and passenger transport in Alabama.

10. Rio–Antirrio Bridge (Charilaos Trikoupis Bridge) – Greece*

Note: Though frequently mistaken as U.S.-based, this is actually in Greece and included here to clarify its non-U.S. location. It’s not among the longest bridges in the USA.

📌 Where Are the Longest Bridges in the US Located?

As the rankings show, most of the longest bridges in United States are concentrated in the Southeast, especially Louisiana and Florida. This is largely due to the region’s swampy, coastal, and water-heavy terrain that requires long spans to ensure safe and efficient transportation.

🏁 Final Thoughts

From the 24-mile Lake Pontchartrain Causeway to the scenic Seven Mile Bridge in the Florida Keys, the longest bridges in the USA are symbols of ambition, engineering, and connectivity. They’re not just roads—they’re landmarks that support economic growth and national unity.

Whether you’re a travel enthusiast, engineer, or curious explorer, visiting one of the longest bridges in the US can offer you a deeper appreciation for America’s infrastructure. Plan your next road trip around one of these incredible structures!

If you’re interested in places that offer not just amazing infrastructure but also great environments for families, check out the Top 10 Best Cities to Raise a Family in the US. These places are not only safe and well-connected, but some are also located near iconic bridges!

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