The 5 Longest Bridges in the US

The total area of ​​the United States is over 3.8 million square miles, of which rivers, lakes, coastal territorial waters and other waters account for 269,717 square miles.

Since various bodies of water covered half of the United States, it was very difficult for Americans to travel from one state to another. This led to the development of sturdy bridges connecting different parts of the United States, making travel and communication between regions more convenient.

In our article, we have listed down the top 5 longest bridges in the United States that have played a vital role in connecting various regions of the U.S. These bridges have not only improved transportation but also boosted the economic development of the regions they connect.

List of longest bridges in the United States

Here is a list of the five longest bridges in the United States, which are considered some of the most impressive engineering feats in the country.

These bridges span bodies of water, connecting different regions and highlighting the importance of infrastructure in connecting communities.

  • Lake Pontchartrain Causeway – 24 miles
  • Manchac Swamp Bridge – 23 miles
  • Atchafalaya Basin Bridge – 18.2 miles
  • Chesapeake Bay Bridge-Tunnel – 17.6 miles
  • Bonnet Carré Spillway Bridge – 11 miles

Lake Pontchartrain Causeway

Lake Pontchartrain Causeway

Source: Volkert

  • Length: 24 miles
  • Located in: Louisiana
  • Built: 1956
  • Renovation: Lake Pontchartrain

Built by the Greater New Orleans Expressway Commission in 1956, the Lake Pontchartrain Bridge is the longest bridge in the United States at 24 miles long. It connects the New Orleans suburb of Metairie to Mandeville on the north shore of Lake Pontchartrain.

The lake is listed in the Guinness Book of World Records as the world’s longest continuous bridge across water. The causeway provides an important transportation link for residents and tourists traveling between the two places.

Manchac Swamp Bridge

Manchac Swamp Bridge

Source: Flickr

  • Length: 23 miles
  • Located in: Louisiana
  • Built: 1979
  • Transformation: Manchac Swamp

The Manchac Swamp Bridge is the second longest bridge in the United States, spanning the Manchac Swamp in Louisiana. It is a double concrete trestle bridge that spans the swamp and connects I-55, an important transportation hub between the cities of Baton Rouge and New Orleans.

The Manchac Swamp Bridge offers stunning views of the surrounding wetlands and is a popular spot for bird watching and wildlife observation. It is also one of the longest free bridges and one of the longest freeway bridges.

Atchafalaya Basin Bridge

Atchafalaya Basin Bridge

Source: 99.9 KTDY

  • Length: 18.2 miles
  • Located in: Louisiana
  • Built: 1973
  • Transformation: Atchafalaya Basin

The Atchafalaya Basin Bridge, also known as the Louisiana Memorial Sky Bridge, is the third longest bridge in the United States at over 18 miles long. It spans the Atchafalaya Basin, connecting Interstate 10 and serving as an important transportation hub between Lafayette and Baton Rouge.

This is a pair of parallel bridges that are adjacent to each other and meet while crossing the Whiskey Bay Navigation Channel and the Atchafalaya River. Also, this bridge is a bit tricky to navigate, as accidents often occur near the intersection of the two rivers due to the narrow crossing of both rivers and the lack of shoulders.

Chesapeake Bay Bridge-Tunnel

Chesapeake Bay Bridge-Tunnel

Source: Chesapeake Bay Magazine

  • Length: 17.6 miles
  • Located in: Virginia
  • Built: 1964
  • Transformation: Chesapeake Bay

The Chesapeake Bay Bridge-Tunnel is the fourth longest bridge in the United States at 17.6 miles long. It connects the Eastern Shore of Virginia to the mainland. The bridge-tunnel is considered an engineering marvel for its unique design and construction.

The crossing involved two tunnels, each more than a mile long, built under the main waterway. Four artificial islands were built in the water at an average depth of 40 feet to serve as road access to the tunnels.

I-10 Bonnet Carré Floodway Bridge

I-10 Bonnet Carré Floodway Bridge

Source: Healthy Gulf

  • Length: 11 miles
  • Located in: Louisiana
  • Built: 1972
  • What’s Transformed: Bonnet Carré Floodway, Lake Pontchartrain, and LaBranche Wetlands

The I-10 Bonnecarré Floodway Bridge is the fifth longest bridge in Louisiana, spanning 4.2 miles across Lake Pontchartrain. Completed in 1972, the bridge is a key transportation hub between New Orleans and Baton Rouge, handling more than 50,000 vehicles per day.

Built on top of the Bonnet Carré Floodway, a flood control structure that diverts excess water from the Mississippi River during flooding. Located in St. Charles Parish, Louisiana, the spillway plays an important role in protecting the surrounding area from flooding.

Interesting Facts About America’s Longest Bridge

  1. The undisputed champion is Louisiana’s Lake Pontchartrain Causeway, which spans 23.87 miles (38.4 kilometers) across the vast Lake Pontchartrain. That’s longer than driving across Manhattan!
  2. It is not uncommon to spot alligators while driving over these long bridges, especially over the Manchac Swamp Bridge. The construction team even had to take special measures during construction to protect these prehistoric reptiles.
  3. The Lake Pontchartrain Causeway is more than just a bridge. It’s also a popular running track for marathons and running competitions. Also, the original plan for the Lake Pontchartrain Causeway was to build a tunnel! However, due to the soft soil, a bridge was considered a more viable option.
  4. The Sunshine Bridge is informally known as the “Bridge of Sighs,” most likely because of several suicides that have occurred there in the past.
  5. Long bridges like the Mackinac Bridge in Michigan, which spans the Straits of Mackinac, must be able to withstand strong winds. It even has a special de-icing system to prevent ice from forming in the winter.
  6. Not all long bridges are free. You have to pay a toll to cross them, such as the Golden Gate Bridge in California.
  7. Although no longer the longest bridge, the Brooklyn Bridge in New York City is a historic landmark. It was the first suspension bridge to use steel cables as its main cables.