AARoads Forum

National Boards => Bridges => Topic started by: MCRoads on August 18, 2021, 11:21:19 PM

Title: The longest bridge in New Orleans, and other counter-intuitive bridge facts!
Post by: MCRoads on August 18, 2021, 11:21:19 PM
Here is a counter-intuitive fact: the longest bridge structure in the US is NOT the Ponchatrain Causeway. It is, in fact, on I-55/I-10/I-310. It is 14 miles longer!

Here are the google maps directions for proof:

I-55/I-10/I-310: https://goo.gl/maps/QFbWkzBYkNEBPwq6A
Ponchatrain Causeway: https://goo.gl/maps/vFrEqCenaKwdvPLB6

Edited to add: This bridge structure is 4 miles longer than the longest officials reccognised road bridge, in Bangkok!

Anyone else got any facts about bridges that don’t seem right?
Title: Re: The longest bridge in New Orleans, and other counter-intuitive bridge facts!
Post by: Roadgeekteen on August 18, 2021, 11:38:12 PM
I wonder why they don't count it as a bridge.
Title: Re: The longest bridge in New Orleans, and other counter-intuitive bridge facts!
Post by: MCRoads on August 19, 2021, 12:06:12 AM
Quote from: Roadgeekteen on August 18, 2021, 11:38:12 PM
I wonder why they don't count it as a bridge.
I think because technically it is 3 bridges that connect to each other via smaller connector ramps. The bridges are the Manchac Swamp Bridge on the I-55 portion of the structure, the I-10 Bonnet Carré Spillway Bridge, and an unnamed bridge on the I-310 portion of the structure.
Title: Re: The longest bridge in New Orleans, and other counter-intuitive bridge facts!
Post by: achilles765 on August 19, 2021, 03:29:35 AM
Quote from: MCRoads on August 19, 2021, 12:06:12 AM
Quote from: Roadgeekteen on August 18, 2021, 11:38:12 PM
I wonder why they don't count it as a bridge.
I think because technically it is 3 bridges that connect to each other via smaller connector ramps. The bridges are the Manchac Swamp Bridge on the I-55 portion of the structure, the I-10 Bonnet Carré Spillway Bridge, and an unnamed bridge on the I-310 portion of the structure.

just fyi, the 310 bridge is called the "Labranche wetlands bridge"
Title: Re: The longest bridge in New Orleans, and other counter-intuitive bridge facts!
Post by: kphoger on August 19, 2021, 10:01:36 AM
So, the longest bridge is actually three short bridges.

meh.
Title: Re: The longest bridge in New Orleans, and other counter-intuitive bridge facts!
Post by: MCRoads on August 19, 2021, 02:42:43 PM
Quote from: kphoger on August 19, 2021, 10:01:36 AM
So, the longest bridge is actually three short bridges.

meh.

The 55 and 10 bridges are both around 20 miles long, so they aren't really "short" ..
Title: Re: The longest bridge in New Orleans, and other counter-intuitive bridge facts!
Post by: Rothman on August 19, 2021, 02:49:09 PM


Quote from: MCRoads on August 19, 2021, 02:42:43 PM
Quote from: kphoger on August 19, 2021, 10:01:36 AM
So, the longest bridge is actually three short bridges.

meh.

The 55 and 10 bridges are both around 20 miles long, so they aren't really "short" ..

Sure they are, when making appropriate comparisons.
Title: Re: The longest bridge in New Orleans, and other counter-intuitive bridge facts!
Post by: US 89 on August 19, 2021, 02:51:43 PM
Always wondered what the longest bridge structure in the US was. I've always been impressed every time I've gone to Charleston and driven I-526, which has a 5 mile long viaduct from US 52/78 across the Cooper River to Clements Ferry Road near Daniel Island.

Title: Re: The longest bridge in New Orleans, and other counter-intuitive bridge facts!
Post by: SteveG1988 on August 21, 2021, 11:39:01 PM
It is a decently big structure, but it is three different projects all linked into each other. The i-55 bridge has one ding against it... it's a bridge due to just being above a body of water in a swamp, if it was built at an earlier period of history it would probably have been on landfill with no care taken for the enviroment, like US51 next to it.
Title: Re: The longest bridge in New Orleans, and other counter-intuitive bridge facts!
Post by: roadman65 on September 08, 2021, 09:22:26 AM
I believe they mean the Ponchatrain is the longest single continuous structure in the US.
Title: Re: The longest bridge in New Orleans, and other counter-intuitive bridge facts!
Post by: Urban Prairie Schooner on September 10, 2021, 09:32:56 PM
Quote from: Roadgeekteen on August 18, 2021, 11:38:12 PM
I wonder why they don't count it as a bridge.
They are technically viaducts that cross land for the most part, though the land in question is swamp/marsh that is non-viable for a surface route.
Title: Re: The longest bridge in New Orleans, and other counter-intuitive bridge facts!
Post by: jeffandnicole on September 10, 2021, 10:14:24 PM
Quote from: Urban Prairie Schooner on September 10, 2021, 09:32:56 PM
Quote from: Roadgeekteen on August 18, 2021, 11:38:12 PM
I wonder why they don't count it as a bridge.
They are technically viaducts that cross land for the most part, though the land in question is swamp/marsh that is non-viable for a surface route.

A viaduct is still a bridge.

Every bridge that goes over another roadway is a bridge over land, but they're not termed viaducts.
Title: Re: The longest bridge in New Orleans, and other counter-intuitive bridge facts!
Post by: MCRoads on September 14, 2021, 09:27:55 AM
Quote from: jeffandnicole on September 10, 2021, 10:14:24 PM
Quote from: Urban Prairie Schooner on September 10, 2021, 09:32:56 PM
Quote from: Roadgeekteen on August 18, 2021, 11:38:12 PM
I wonder why they don't count it as a bridge.
They are technically viaducts that cross land for the most part, though the land in question is swamp/marsh that is non-viable for a surface route.

A viaduct is still a bridge.

Every bridge that goes over another roadway is a bridge over land, but they're not termed viaducts.

The Atchafalaya Basin Bridge goes over similarly swampy land, and it is considered one of the longest bridges in the world. Also, the official longest road bridge in the world is an urban expressway, so make of that what you will...