Driving the Lake Pontchartrain Causeway: The Longest Overwater Bridge in the World

There’s a lot of good day trips out of New Orleans and one of my favorite ones is a trip across the Lake Pontchartrain Causeway.

It’s the longest overwater bridge in the world and it’s a lot of fun to drive over and explore the North Shore of Lake Pontchartrain.

In this article, I’ll give you some insight into this magnificent bridge and talk about our recent trip across the massive lake.

History of the Lake Pontchartrain Causeway

The concept of connecting Lake Pontchartrain with a bridge can be traced back to the early 19th century, thanks to the visionary Bernard de Marigny, founder of Mandeville.

Marigny was an iconic French-Creole American who was known for a lot of things like funding the first organized New Orleans Mardi Gras celebration in 1833 and bringing the dice game of “hazard” back from England (which would become the dice game many know as “craps”).

At one point he was possibly the richest teenager in the world but would end up losing it all, largely because of a spending and gambling addiction.

Anyway, Marigny kickstarted the transportation evolution by establishing a ferry service, which continued its operations until the mid-1930s.

In the 1920s, an ambitious proposal emerged for the creation of artificial islands linked by a network of bridges. The funding for this plan aimed to be generated by selling home sites on these islands but it never came intro fruition.

It wasn’t until 1948 that the modern causeway concept took shape.

The original causeway was a two-lane span, measuring 23.86 miles (38.40 km) in length. It opened in 1956 at a cost of $46 million (the equivalent to $380 million in 2022 dollars). The northbound causeway was completed in 1969.

Lake Pontchartrain Causeway

Our experience driving on the bridge

We started off on a late afternoon weekday and hit the first “span” at exactly 3:02 pm.

The southbound artery boasts an impressive 2,246 spans, with span dimensions averaging 28 feet in width by 56 feet in length.

Meanwhile, its northbound counterpart boasts 1,506 spans, slightly longer at 84 feet, yet maintaining the same width. (Notice the size difference of the spans in the photo below.)

Beneath these colossal structures, over 9,000 piles provide essential support, with each pile averaging a staggering 90 feet in length.

Lake Pontchartrain Causeway

As we made our way on the bridge we rolled all the windows down and cranked up the music making for a nice mini road trip. I highly recommend it.

It seemed like a relatively calm day over the lake and it wasn’t particularly windy but I’ve heard driving over the bridge during a storm can be a bit nerve-racking and obviously it has been battered by hurricanes in the past.

Amidst the tumult of Hurricane Katrina, the bridge faced a test of its resilience, with a total of 17 spans succumbing to the ferocious winds and waters. However, amidst this trial by nature’s fury, the structural foundations held firm.

Lake Pontchartrain Causeway

One interesting thing about the bridge is that it doesn’t sit very high above the water. The spans have a 10 foot clearance, which makes some people nervous.

The water levels in Lake Pontchartrain average about 2 to 14 feet in depth, although I think some portions under the bridge are dredged much deeper.

If you’re wondering about the size of Lake Pontchartrain, it’s one of the largest lakes in the country coming in at number eleven with 631 sq mi. It’s incredibly vast and when you’re in the middle of the bridge you may not even be able to see land.

What’s kind of crazy though is that the size of Lake Pontchartrain is nothing compared to Lake Superior, the largest lake in the US, which comes in at the size of 31,700 sq mi. That really puts things into perspective.

Lake Pontchartrain Causeway

Emergency stops

Some people are a bit freaked out to drive over this ultra-long bridge and worry what would happen in the event of an emergency. The good news is that you can pull off or turn around at certain points.

The highway boasts 6 northbound and 6 southbound segmented shoulders, also known as safety bays, with lengths ranging from 600 to 1,008 feet. You’ll see signs for these as you approach them making it easy to turn into them if needed.

Additionally, there are 7 strategically placed crossovers between the spans, exclusively designated for emergency stopping purposes. We actually witnessed emergency vehicles tending to a situation at one of these crossovers in our trip across the bridge.

Lake Pontchartrain Causeway shoulder

The longest overwater bridge in the world

The Lake Pontchartrain Causeway is the longest overwater bridge in the world… at least to some. More accurately, it’s the “longest continuous overwater bridge.”

Personally, I don’t think it should need that qualifier because aggregate bridges, those that cross a combination of water and land, should not be in the “overwater” category at all.

To me, it seems significant that a bridge is totally over water and it shouldn’t be lumped in with those that go back and forth (water, land, water, land, etc.) and others that also use tunnels.

I think continuous should be a given when it comes to titles like this or even other titles like the oldest (continuously opened) restaurant in the US. But that’s just me.

Anyway, it took us about 25 minutes to get across the bridge but others who go for efficiency can get across in closer to 20 minutes, maybe even 19 or 18 minutes. But I suggest reasonably adhering to the the speed limit signs, as there were several law enforcement vehicles on the bridge during our drive.

Lake Pontchartrain Causeway


Eventually, we arrived in Mandeville and explored the Mandeville Lakefront, home to beautiful southern live oak trees.

It’s a great place to go for a walk, and I would highly recommend you to get out of your vehicle and walk around to admire some of the views.

Not sure about getting into that brackish water though…. It’s not so much the gators but the bull sharks!

Mandeville Lakefront

We also made a way over to Sunset Point Park, where we got some good views and also spotted an alligator!

Mandeville Sunset Point Park alligator

There’s quite a few highly rated restaurants in Mandeville. We had just filled up at Heard Dat Kitchen in New Orleans so we didn’t have room for entrées but we did stop at the amazing snow cone shop.

So I’d recommend taking the trip over the bridge from New Orleans and plan on enjoying a lunch or maybe a snowball before returning back.

Final word

Overall, I think driving over the Lake Pontchartrain Causeway is a great day trip from New Orleans. Plan on taking about three hours or longer depending on how much exploring you want to do but it will be worth it, especially on a nice and breezy spring day like we had.

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