What would be your area's "Carmageddon"?

[golden eagle]

As many of your highway geeks, er, enthusiasts know, a ten-mile stretch of Los Angeles' 405 freeway is scheduled to be shut down this coming weekend. We all know how legendary traffic is there. Even with advance warning, who knows how the traffic will really be. Anyhow, what would be areas of your city if a major shutdown were to happen? For Jackson, it would be shutting down the Stack interchange (I-20/I-55/US49). Jackson is not that big, but we saw what could happen last winter when a stretch of the Stack was shut down due to icing on the bridges. It took some people as much as five hours to get through it. At the same time, a number of other bridges, particularly at I-55/I-220 in north Jackson, were shut down too, causing northbound traffic to divert primarily unto State Street (the old US 51). I live right off State Street and I've never seen that many cars on the road. Fortunately, I was going to opposite direction.

I was in San Diego in 2003 when a construction crane accidentally toppled a power line near the I-5/805 interchange, causing the biggest traffic tie-up in the city's history. Thankfully, I didn't own a car or have any reason being in the area.

[rickmastfan67]

In Pittsburgh, it would be closing of either the Ft. Pitt Tunnel or the Squirrel Hill Tunnel.

And Super-"Carmageddon" would be both of them closed at the same time, which I think only happened once because of bomb threats for both tunnels at the same time (which included the Liberty Tunnel as well).  Happened back in '07.
http://www.wpxi.com/news/13422006/detail.html

[NE2]

Hurricane Charley.

[Bickendan]

A powerline fell on the Sunset Highway March 14th, 2004, shutting down US 26 and the Blue Line MAX between Portland and Beaverton. With the freeway and light rail closed, traffic got tied up on all roads crossing the Tualatin Mountains -- OR 10 (Capitol Hwy/Beaverton-Hillsdale Hwy), OR 8 (Canyon Rd, essentially inaccessible because it branches off the Sunset), W Burnside St and NW Cornell Rd.

It's not this bad whenever a president decides to visit and shut down the Banfield (I-84/US 30--er, "QC 366").

[agentsteel53]

I don't know, but it rhymes with 9.0

[ftballfan]

In Manistee, MI, this happens quite often when a large freighter or a sailboat goes up the river. Traffic is backed up for hundreds of yards when both bridges are in the open position. There has been an example of a long-term carmageddon, and that happened when the four-lane Memorial Bridge was shut down for rehabilitation back in 2004-05, forcing traffic to either use the two-lane Maple Street Bridge or go miles out of the way (either via Filer City, Stronach, and Eastlake or via Baldwin, Mesick, and Buckley).

Another example was when both routes out of Manistee to the south (US-31 and Quarterline Rd) were washed out due to heavy rains in 2008. It lengthened a normally half-hour (or shorter) trip from Ludington to Manistee to approximately 90 minutes via M-55, M-37, and US-10.

[1995hoo]

Seems like whenever we get snow, we have a traffic apocalypse. Back in 2008 we got an ice storm on the day of the presidential primary. The Springfield Interchange iced over and people were stuck for four or more hours. This past January a snowstorm hit after it rained all day and washed away the pretreatment stuff on the roads. Result: Hundreds of cars abandoned on the GW Parkway alone and lots of people reporting 13-hour commutes home.

On the whole I'd rather deal with the massive road closures that accompany a presidential inauguration than put up with the nonsense that goes with snow around here. At least with an inauguration you know exactly when it is and they give ample advance warning of exactly what the traffic-management plans are. Can't do that with much certainty in advance of snow.  

[kharvey10]

December 8, 2010 in the St. Louis Metro East was a major carmageddon when a major accident shut down one of the bridges on I-270 right before the morning rush hour.  Well, it had to be the Chain of Rocks Bridge, and those 50k vehicles had to go somewhere.  It was a 12 mile backup from the Poplar St. Bridge to IL 157 on 55/70 westbound and a five mile backup on IL 143 from the Clark Bridge to Wood River.  It took at least 3 hours for people just to cross the river.

Get this: that was not the first carmageddon involving that bridge.  Expansion joint failures in August 1994 caused two days of infamous traffic jams during the morning rush.

[Scott5114]

Oklahoma City's freeway system is robust enough that if any one freeway were shut down there would still be multiple ways of bypassing it. Even if the Dallas Junction (I-35/40/235) were shut down, I-40 traffic could bypass on I-44->I-35 or I-44->240 and I-35 and I-235 traffic could bypass with I-44->I-240. There are tons of surface arterials too so depending on the blockage you might not even need to use a freeway.

[deathtopumpkins]

Easy. Closing of both the Hampton Roads and Monitor-Merrimac bridge-tunnels. This happened once last summer (I believe on the 4th of July weekend too) when the HRBT's floodgates were stuck open during a test, an accident shut down the Monitor-Merrimac, and the only other crossing of the harbor apart from a ferry, the James River Bridge, was closed due to downed power lines. That day was a traffic hell and everyone remembers it. News articles STILL mention how it was a glaring indication of how these crossings limit the mobility and thus well-being of the region.

[myosh_tino]

Up here in the S.F. Bay Area, closing the Bay Bridge or the Golden Gate Bridge would cause a traffic nightmare.  In the case of the Bay Bridge, it actually happened back in 1989 when the Oct 17 earthquake caused a section of the bridge to collapse taking it out of service for weeks.

[Scott5114]

Wasn't the Bay Bridge also closed for maintenance a couple years back?

[TheHighwayMan3561]

Twin Cities: Closing I-94 between the downtowns.

Duluth: Closing I-35 between Grand Ave and I-535.

[myosh_tino]

Wasn't the Bay Bridge also closed for maintenance a couple years back?

It was closed over a couple of Labor Day weekends  to move temporary road decks into place while the new eastern span is being built but traffic wasn't bad because of the holiday.  It was also closed recently when a temporary fix on a damaged I-bar failed causing a chunk of metal and a metal cable came crashing down onto the road deck.  IIRC, the closure was only for a couple of days but don't get me wrong, the traffic was bad.

[Quillz]

Closing of I-405 between US-101 and I-10 this coming weekend. I'm just going to stay home. I imagine CA-27, I-5 and any other major highway that connects the valley to the rest of LA is going to be raped.

[Zmapper]

Fort Collins Carmageddon is whenever a train on the BNSF line passes through. Not a single overpass or underpass for cars in the whole town.

[texaskdog]

Austin is a "build it & they wont come" city so we dont have any east/west freeways as it is, but if both decks of I-35 were out of commission for some reason, Mopac, 183, and Lamar really wouldnt do much to handle the traffic.

[bulldog1979]

In my hometown of Negaunee, MI, we had it happen once that BUS M-28 (Teal Lake Avenue) was closed over a traffic accident by the US 41/M-28 intersection while Baldwin Avenue was shut down for maintenance for the LS&I rail crossing. That even essentially severed the town in two. The only way from the south side of the highway to the north was to take BUS M-28 to Ishpeming and follow the highway back to Negaunee or take CR 480 to M-35 to either CR 492 or US 41/M-28.

A train alone running through town can't tie up both intersections because Teal Lake Avenue has an overpass for the rail line, but the Baldwin Avenue crossing is at-grade. We were hoping several years ago that a connection between Prince Street and CR 491 (Maas Street) would be re-established as a third way across town, but it didn't come to pass.

[Ga293]

Carmageddon here would probably be the shutdown of the I-75/285 Cobb Cloverleaf interchange. There's absolutely no alternative that could handle these freeways' traffic in a light time of day, let alone at rush hour.

[realjd]

Around here? Space Shuttle launches and hurricanes. Unfortunately we won't be seeing any more of the former.

[Ian]

The Schuylkill Expressway definitely, as well as NJ 42 in New Jersey between the Walt Whitman Bridge (I-76) and the Atlantic City Expressway would be a nominee for the Philadelphia area. You could argue about I-476, especially the 2 lane portion between I-95 and PA 3 (exit 9).

[vdeane]

Rochester, NY:
-I-90 between NY 332 and I-490/NY 96
-The I-590/I-490 interchange
-probably the I-590/I-390 and I-390/I-490 interchanges too

Potsdam, NY:
-Though it's an hour and a half away, I-81 and I-87, due to the inability to go anywhere in the US without these roads.  Happens every winter; we might as well join Canada, because it can be reached more consistently
-more locally, US 11, particularly the intersection between US 11/NY 345/Maple St/Clarkson Ave
-probably anywhere in "downtown" Potsdam

Sidney, NY:
-NY 8 between I-88 and NY 7
-probably Delaware Ave, Union St, Main St/Ostego CR 1A, and River St

[tdindy88]

In Indianapolis, likely the Hyperfix Project in the mid-2000s. They closed off the section of I-65/I-70 between the North and South Splits for some 50 days during the summer to reconstruct the pavement and rebuild bridges (interestingly they kept the button-copy signs.) They reconfigured and rebuilt some of the downtown roads during the time to hold more traffic and advertised it out along the outer freeways. Still, one could drive downtown for rush hour no problem, it was that you couldn't drive through downtown. The project ended ahead of schedule and few people probably still remember it.

If you want a yearly verision of Carmaggedon, there's Race Day (specifically the Indy 500 race day.) Craming 400,000 additional people into the Speedway is no easy task but it somehow gets done. While the interstates don't suffer too much, except along the western leg of I-465, the arterials such as 16th Street, Crawfordsville Road, and Georgetown Road can be bumper to bumper in each direction (even under contraflow conditions.) Native Indianapolis residents know that unless you are attending the race, you DO NOT go on the Westside on Race Day.

[J N Winkler]

Oklahoma City's freeway system is robust enough that if any one freeway were shut down there would still be multiple ways of bypassing it. Even if the Dallas Junction (I-35/40/235) were shut down, I-40 traffic could bypass on I-44->I-35 or I-44->240 and I-35 and I-235 traffic could bypass with I-44->I-240. There are tons of surface arterials too so depending on the blockage you might not even need to use a freeway.

Wichita does not have quite the same degree of redundancy.  North-south movements are served by I-135 and I-235, which run close enough together that in many parts of the city they are plausible detours for each other, but using I-235, K-96, and the Turnpike in combination to avoid blockages on Kellogg would entail a significant degree of out-of-the-way travel for most of the city.  The surface arterials have plenty of spare capacity but accidents on Kellogg still produce long queues since Wichitans in general have become overly dependent on it for cross-town journeys.  When Wichita-area traffic problems are mentioned in news media Twitter feeds, Kellogg is involved somehow about four times out of five.

Aside from the freeways, the major source of long tailbacks on city streets used to be the railroad crossings.  This is much less of an issue now that the Central Corridor railroad overpass has been finished, though the moiety of rail traffic that still uses the line parallel to Zoo Boulevard can cause long queues during the day.

[Mergingtraffic]

In CT it would be I-95, but we already had a similiar issue and things were pretty much ok.  I-95 was shut down in Bridgeport about 7 years ago due to an accident.  They had to replace a bridge and the highway was closed for a couple days.  There was so much warning, traffic wasn't as bad as predicted.