Louisiana’s Longest Interstate Stretch Without Exits – Where Is That?

(KMDL-FM) For the weary traveler in Louisiana, they are the promised land. They are bathrooms and beverages. They are food and lodging. They are that diversion that gets you out of the white-knuckle traffic onto a more sedate style of driving. They are the exits off of our Interstate highways. 

But have you ever wondered what is the longest distance you can drive on an Interstate Highway in Louisiana without encountering a way to get off the roadway is?

Google Maps Google Streetview

Okay, for you guys with 4-wheel drive trucks, a way to legally and safely get off the roadway? We realize that some of you don't need an actual exit to exit the roadway.  Believe it or not, the longest stretch of Interstate Highway without any exits is more than 20 miles long, and no, it's not over the Atchafalaya Basin.

What Interstate Highways Are in Louisiana?

Louisiana is served by four major Interstate highways, and we also have some intermediate stretches that are in-state only, and of course there are some loops and spurs as well. The four major interstates that serve Louisiana are I-10 and I-20, that handles east/west traffic. There are also I-49 and I-55, which handle north/south traffic.

READ MORE: I-14 Proposed For Louisiana - What is the Latest?

I-12 is also in the state; that would be the intermediate stretch, and there are loops in Lake Charles, Shreveport, Baton Rouge, and New Orleans, but all of those Interstates have an exit at least every few miles.

Sal Media via Unsplash

Speaking of miles, you've probably noticed the mile marker signs posted along the roadway; those are to give motorists an idea of where they are exactly on the roadway. You may have noticed that some mile marker signs not only have a mile designation but a decimal point too.

Why Do Some Mile Markers Include a Decimal Point?

Those tenth-of-a-mile markers are often used on long bridges or stretches of roadway where the exact location of a motorist or disabled vehicle needs to be known for safety and recovery reasons.  It might also help a stranded motorist know if they are heading in the right direction, especially on a long bridge, if emergency services are needed.

I-49 at Judson Walsh Exit, google street view

Since we have already told you the longest stretch of interstate without any exits in Louisiana isn't over the Atchafalaya Basin, where do you think it is? It's over a swamp, but it's not on I-10. It's on I-55 and covers the distance between LaPlace and Pontchatoula.

The Manchac Swamp Bridge is 22.8 miles long. There are no entrances or exits, or even shoulders, for the entire length of the twin-span concrete trestle structure. The Basin Bridge comes in at 18.2 miles, and the Lake Pontchartrain Causeway is not an Interstate Highway.

READ MORE: Best Places to Eat on I-10 in South Louisiana

So, there you go; you now have your next bar bet information. And speaking of bars, if you're going to be driving, don't visit them, but if you're off the road, thanks to a nearby exit, then please take advantage of this important reference material.