Discover the 6 Longest Bridges in Louisiana

What comes to mind when you think of Louisiana? Mardi Gras, jazz music, and delectable Cajun cuisine are all staples of Louisiana living, but did you know it also has six of the longest bridges in the United States? From a 24-mile behemoth crossing Lake Pontchartrain, to a 5.4-mile memorial bridge built just 17 years ago, Louisiana offers remarkable views for bridge enthusiasts. Keep reading to discover more about the six longest bridges in Louisiana and where they stack up against other bridges across the United States.

From Jazz to Jambalaya: Louisiana’s Unique Cultural Ambiance

Louisiana may be home to six of the longest bridges in the United States, but those bragging rights are often overshadowed by the undeniable heart and soul synonymous with this southern region. As a melting pot of several cultures, including African, French, American, and French-Canadian, the people, places, and activities are as diverse as each Southern family’s gumbo recipe. And while we commonly think fondly of the music and laughter that engulfs Bourbon Street, the airboat tours zipping through the bayou, or the wild parties of Mardi Gras, Louisiana have also earned a badge of honor and resilience after rebuilding when Hurricane Katrina ripped through its streets.

Types of Bridges

There is a plethora of different types of bridges throughout the world. However, judging by the following list, it appears there are a select few that can withstand the engineering demands required to support roads along greater distances. Surprisingly, all six of the longest bridges in Louisiana fall under two different bridge types: trestle and beam. What is even more shocking is that trestle bridges aren’t considered one of the most commonly built bridges! So, what are trestle and beam bridges?

Trestle Bridges

Trestle bridges are built using closely spaced frames across the entire length of the waterway. These rigid frames, referred to as trestles, are what provide the bridge with unwavering support. The trestles are commonly made of timber, iron, steel, and sometimes concrete.

Beam Bridges

Also known as a stringer bridge, the beam bridge is one of the more commonly known bridge types to engineers. Considered one of the simplest types of bridges, this method of construction uses multiple support beams, commonly referred to as I-beams due to their “I” shape, to support the bridge deck.

The 6 Longest Bridges in Louisiana

Bridging the gap from soulful food and festivities to impressive transportation construction, there are six notable bridges within the borders of Louisiana. These structures range from a record-breaking 24 miles to a still impressive 5.4 miles. All six of these remarkable bridges are located in the southeast portion of the state.

1. Lake Pontchartrain Causeway

Length: 23.875 miles

Bridge Type: Trestle

Built: 1956 (southbound), 1969 (northbound)

Location: Lake Pontchartrain

Longest Bridge in the United States

The Lake Pontchartrain Causeway is not only the longest bridge in Louisiana or even the United States. According to the Guinness World Records, it is currently considered the longest continuous span over water in the world! What’s doubly impressive is that this bridge consists of two parallel road bridges.

2. Manchac Swamp Bridge

Length: 22.8 miles

Bridge Type: Trestle

Built: 1979

Location: Manchac Swamp

2nd Longest Bridge in the United States

The second longest bridge in Louisiana, the Manchac Swam Bridge, is extremely close to the Lake Pontchartrain Causeway, in both length and geographic location! Less than an hour away from each other, the Manchac Swamp Bridge comes in a close second on the list measuring just shy of 23 miles long. This twin concrete trestle bridge allows Interstate 55 and U.S. Route 51 to safely travel across the Manchac Swamp.

3. Atchafalaya Basin Bridge

Length: 18.2 miles

Bridge Type: Beam

Built: 1973

Location: Atchafalaya Basin

Connects Baton Rouge and Lafayette

3rd Longest Bridge in the United States

While it was the second longest bridge in the United States when it was completed in the 1970s, the Atchafalaya Basin Bridge has since been bumped to third place. Also referred to as the Louisiana Airborne Memorial Bridge, this structure is a pair of parallel bridges as well. Reaching a still-impressive 18.2 miles in length, this beam bridge guides Interstate 10 over the Atchafalaya Basin and connects the two cities of Baton Rouge and Lafayette.

4. I-10 Bonnet Carré Spillway Bridge

Length: 11 miles

Bridge Type: Trestle

Year Built: 1972

Location: Bonnet Carré Spillway, Lake Pontchartrain, and LaBranche Wetland

Connects New Orleans and Baton Rouge

5th Longest Bridge in the United States

Similar to our third-place entry, the I-10 Bonnet Carré Spillway Bridge consists of Interstate 10 traffic. However, this bridge is the first of our list to accompany travelers across several bodies of water, including Lake Pontchartrain. In addition to this massive lake, the I-10 Bonnet Carré Spillway Bridge traverses the Bonnet Carré Spillway and the LaBranche Wetland. This twin concrete trestle bridge has a total length of 11 miles and connects Baton Rouge with New Orleans.

5. Louisiana Highway 1 Bridge

Length: 8.257 miles

Bridge Type: Trestle

Year Built: 2009

Location: Bayou Lafourche and Marshes

Connects Leeville to Port Fourchon

6th Longest Bridge in the United States

Louisiana Highway 1 Bridge, also commonly referred to as the Gateway to the Gulf Express, is a part of The LA 1 Improvement Project, which plans to connect Leeville, Golden Meadow, Grand Isle, and Port Fourchon. This concrete trestle bridge specifically unites the bay area of southern Louisiana, creating passage between Leeville and Port Fourchon. At just over eight miles, this bridge travels over Bayou Lafourche and several marshes.

6. Frank Davis “Naturally N’Awlins” Memorial Bridge

Length: 5.4 miles

Bridge Type: Trestle

Year Built: 2010

Location: Lake Pontchartrain

Connects New Orleans to Slidell

12th Longest Bridge in the United States

Also referred to as the I-10 Twin Span Bridge, the Frank Davis “Naturally N’Awlins” Memorial Bridge is a 5.4-mile-long bridge that again crosses Lake Pontchartrain. Connecting New Orleans to Slidell, the two parallel trestle bridges are the most recently built structures on this list. This memorial bridge fully opened in 2010, replacing the original I-10 Twin Span Bridge, which was damaged extensively by Hurricane Katrina 5 years prior. The new I-10 Twin Span Bridge was renamed the Frank Davis “Naturally N’Awlins” Memorial Bridge in 2014 in honor of Frank Joseph Davis. Davis, who passed in 2013, was an on-air news personality for WWL-TV and regularly spent his time fishing near the bridge.

Louisiana Bridges Dominating in the United States

The Frank Davis “Naturally N’Awlins” Memorial Bridge may only measure 5.4 miles long and seem short compared to the nearly 24-mile Lake Pontchartrain Causeway in the first place. However, don’t let that difference in distance fool you! Although it is number six on this list, “Naturally N’Awlins” is ranked 12^th overall in the United States! Louisiana is home to six of the 15 longest bridges in the country, and four of the top five. I guess you could say Louisiana has bragging rights ‘covered’ in the bridge category.

Is All the Bridge Talk Getting a Little Tolling? Get over It!

Louisiana is a melting pot of food, culture, and festivities, but we can’t forget its contribution to our country’s transportation systems. Across lakes, swamps, bayous, and rivers, Louisiana offers six of the most impressive bridges in the country. If you’re an avid bridge-lover, make sure Louisiana is on your bucket list travel itinerary!