What bridge closure would cause the most chaos/disruption?

[kphoger]

So you wouldn't think of this right away as one but in the grand scheme of causing chaos traffic wise, the Lake Shore Dr bridge over the Chicago River. It's a double decker bridge that carries the quasi freeway of Lake Shore Dr AND the connection to Lower Wacker Dr (a hidden gem express route though the Loop). I magine if LSD was out of commission. All the traffic on LSD would be funneled onto Columbus Dr from Lower Wacker, Michigan Ave and the 90/94 Kennedy/Ryan Expy.

As I said, it would be a nightmare for Downtown Chicago traffic.

More of a problem than the Dan Ryan's bridge over the same river?

[NWI_Irish96]

So you wouldn't think of this right away as one but in the grand scheme of causing chaos traffic wise, the Lake Shore Dr bridge over the Chicago River. It's a double decker bridge that carries the quasi freeway of Lake Shore Dr AND the connection to Lower Wacker Dr (a hidden gem express route though the Loop). I magine if LSD was out of commission. All the traffic on LSD would be funneled onto Columbus Dr from Lower Wacker, Michigan Ave and the 90/94 Kennedy/Ryan Expy.

As I said, it would be a nightmare for Downtown Chicago traffic.

More of a problem than the Dan Ryan's bridge over the same river?

Both would be a nightmare, but the LSD bridge might be worse. With the DR bridge out, traffic can still take 55 to LSD to get downtown. LSD bridge out would dump all that traffic onto Michigan Ave. Ohio/Ontario may be the third worst Chicago River bridge to be out.

[kphoger]

Ohio/Ontario may be the third worst Chicago River bridge to be out.

I'm trying to figure out what rail bridge would be most disruptive to Chicago-based freight operations.

[NWI_Irish96]

Ohio/Ontario may be the third worst Chicago River bridge to be out.

I'm trying to figure out what rail bridge would be most disruptive to Chicago-based freight operations.

Not very familiar with freight operations but my very uneducated guess would be the one between 18th and Canal.

[kphoger]

I'm trying to figure out what rail bridge would be most disruptive to Chicago-based freight operations.

Not very familiar with freight operations but my very uneducated guess would be the one between 18th and Canal.

I'll suggest one of the ones at 75th & Greenwood (there's a bridge over each), as I believe that line connects Norfolk Southern's Park Manor and 47th Street yards—the latter of which is its busiest in the nation—to/from basically everywhere east of Chicago.

[PColumbus73]

The US 17 bridge over the Waccamaw / Pee Dee River in Georgetown, SC would be a problem if it were closed. The next nearest crossing would be US 501 in Conway (about 35 miles north).

Also, closing US 501 in Conway would be a problem, too. Even worse would be US 501 over the Little Pee Dee River.

In the aftermath of Hurricane Florence, nearly all of the Waccamaw River bridges in Horry County were overtopped. SCDOT ended up scrambling to build a temporary flood barrier along US 501 in Conway, reducing the bridge to two lanes.

[kphoger]

Norfolk Southern's ... 47th Street yards ...

By the way, I didn't realize till now that there's a street that runs all the way under this freight yard.  That's pretty impressive!

https://maps.app.goo.gl/UXSED7jNAsNfZcfB7
https://maps.app.goo.gl/YBD17YSMifdK6ZfV6
https://maps.app.goo.gl/JRHQ2EGZvztvZHup7

[Scott5114]

The one over the drainage ditch on US-50 in Nevada.

Why?

It's so lightly traveled that it would go unreported, and cars would be required to backtrack. You need to plan fuel trips and sometimes food trips accordingly, so drivers would get stuck backtracking, sometimes over 100 miles. While it doesn't affect a large number of drivers, it severely affects the ones who do go that way.

That would suck.

Has this happened before?

I doubt it I made the post to be sarcastic.

Many of the similar random bridges on I-80 would likely be pretty chaotic, since for many of them the best detour would be via US-50, requiring a lot of traffic to use it which isn't really prepared for those sorts of conditions.

In Southern Nevada, the I-11 Colorado River bridge being out would be pretty bad, since you'd either have to scramble to get old US-93 across Hoover Dam in usable condition again (assuming the feds even allow that), or else everyone would have to go down US-95 to cross the river at Bullshit City (as my autocorrect so lovingly refers to it).

[LilianaUwU]

The Pont de Québec has occasional weekend closures and they cause massive traffic jams.

Pont Pierre-Laporte will grind to a halt the second any lanes are closed. This one would be the worst closure, as no trucks are allowed on Pont de Québec and they would have to detour to Trois-Rivières, where it's not guaranteed Pont Laviolette will be open either. And the resulting car traffic on Pont de Québec may very well cause its collapse.

[Flint1979]

The one over the drainage ditch on US-50 in Nevada.

Why?

It's so lightly traveled that it would go unreported, and cars would be required to backtrack. You need to plan fuel trips and sometimes food trips accordingly, so drivers would get stuck backtracking, sometimes over 100 miles. While it doesn't affect a large number of drivers, it severely affects the ones who do go that way.

That would suck.

Has this happened before?

I doubt it I made the post to be sarcastic.

Many of the similar random bridges on I-80 would likely be pretty chaotic, since for many of them the best detour would be via US-50, requiring a lot of traffic to use it which isn't really prepared for those sorts of conditions.

In Southern Nevada, the I-11 Colorado River bridge being out would be pretty bad, since you'd either have to scramble to get old US-93 across Hoover Dam in usable condition again (assuming the feds even allow that), or else everyone would have to go down US-95 to cross the river at Bullshit City (as my autocorrect so lovingly refers to it).

Yeah, and just think of the lack of services in that area along US-50. I'm sure along I-80 there are at least exits with services.

[coldshoulder]

An underrated and overlooked bridge(s) would be the ones carrying I-80 west of Youngstown, Ohio over the Meander Reservoir, a regional drinking water facility just east of the Ohio Turnpike interchange (I-76 west; I-80 east).  There's a ton of both general passenger traffic and freight traffic that travels that stretch daily as that area is the approximate halfway point between New York City and Chicago. 

The only viable alternative/detour is County Highway 18 (Mahoning Avenue) that runs parallel to I-80 a few miles south. And although that road has actually been signed as "ALT-80" because of previous construction projects it would be an aggravating alternative given the commercial development along most of the detour and the numerous traffic lights and cross streets.  One positive is that there is an auxiliary interchange on that road with the Ohio Turnpike (built within the footprint of the original 1950's interchange with the Turnpike before I-80 was constructed).

[Revive 755]

An underrated and overlooked bridge(s) would be the ones carrying I-80 west of Youngstown, Ohio over the Meander Reservoir, a regional drinking water facility just east of the Ohio Turnpike interchange (I-76 west; I-80 east).  There's a ton of both general passenger traffic and freight traffic that travels that stretch daily as that area is the approximate halfway point between New York City and Chicago.

OH 5, OH 82, and OH 11 wouldn't work as a partial alternative for through I-80 traffic?

[CoreySamson]

The Horace Wilkinson Bridge in Baton Rouge would be a complete disaster if it closed. All through traffic would have to use the US 190 bridge instead, and traffic backs up already on the I-10 bridge to boot.

Revisiting my answer from 5 years ago, I realize I didn't have my sights set high enough. I-10 between Houston and Baton Rouge is full of bridges that would cause massive disruptions. I count at least 5 bridges that would cause chaos if they were compromised:

- Trinity River bridge in Cove
- Neches River bridge in Beaumont
- Sabine River bridge on TX/LA border
- Atchafalaya River bridge
- Mississippi River bridge in Baton Rouge

For most of these bridges, the closest alternate crossings are an average of around 15 miles away or so. Granted, there are alternate routes (US 90, US 190, TX 12, TX 73), but they are well below I-10's capacity and out of the way. Any of those crossings could become a nightmare.