Most number of highways sharing the same multiplex

[golden eagle]

In Indianapolis, a small section of I-465 is multiplexed with I-74; U.S. highways 31, 36, 40 and 52; and Indiana 37, for a total of seven highways! Are there any multiplexes with as many highways on them?

[njroadhorse]

Probably somewhere in Georgia there is...

[TheStranger]

California's biggest multiplex (both signed and unsigned) is just five miles from me here in Sacramento, on the WX segment of the Capital City Freeway (between I-5 and Route 99) -

US 50
Business 80
Route 99
unsigned I-305

Technically, one could also argue that Route 16 runs through here unsigned as well...

[golden eagle]

The Jackson area has a five-highway multiplex: I-20 & I-55, U.S. 49 & 51 and Mississippi 18 (though 18 is not signed as much).

[Scott5114]

You missed one, golden eagle; there's also US-421, making that an octuplex (8 way concurrency).

From the misc.transport.road FAQ...

Q: Which highway has the most multiplexed routes?

A: I-465 on the east side of Indianapolis, IN, between the US-36/SR-67 and US-40 exits, also carries US-31, US-36, US-40, US-52, US-421, SR-37, and SR-67, for a total of 8 routes on one highway, though only I-465 is posted along this stretch as all other routes following I-465 except I-74 have a sign reading "FOR [route shield][direction]/FOLLOW [I-465 shield]/to Exit [number]" on the onramps where they enter I-465 (see http://illi-indi.com/showFull.php?id=1452&section=34652 ). The most signposted routes is 7 in GA: US-1, US-23, US-301, SR-4, SR-15, SR-23, and SR-121 just short of the FL line ( http://www.gribblenation.com/papics/outofstate/gatotempole-folkston.jpg ). This is possible because in GA every US highway is usually paired with at least one signposted state route (see 7.6.4 ), so other examples with this many or possibly even more may exist elsewhere in the state.

[Bryant5493]

I-20/59/U.S. 11/80/S.R. 19
(Meridian, Lauderdale Co., Miss.)

U.S. 23/29/78/278/S.R. 8/10 - Ponce de Leon Ave. NE
(Atlanta, Fulton Co., Ga.)

U.S. 19/29/41/S.R. 3 - Northside Dr. NW (south of North Ave. NW)
(Atlanta, Fulton Co., Ga.)

U.S. 19/41/78/278/S.R. 3/8 - Northside Dr. NW (north of North Ave. NW)
(Atlanta, Fulton Co., Ga.)

U.S. 78/278/S.R. 5/8 - Veterans Memorial/Bankhead Hwys.
(Cobb/Douglas counties)

I-575/S.R. 5/20/140/417
(Canton, Cherokee Co., Ga.)

U.S. 29/S.R. 14/139/154 - Lee St. SW
(Atlanta, Fulton Co., Ga.)


Be well,

Bryant

[NJRoadfan]

In Greensboro, NC... the area known as "death valley" on I-40 saw the following highways: US-29, US-70, US-220, US-421 (wrong way multiplex, since moved to outer loop), I-40, and Business I-85

[SSOWorld]

Madison WI Beltline - US 12, US 14, US 18, US 151

[Hellfighter]

Let's not forget the I-44/I-55/I-64/I-70/US-40 multiplex over the Mississippi.

[SSOWorld]

Let's not forget the I-44/I-55/I-64/I-70/US-40 multiplex over the Mississippi.

Whether I-44 is part of that is debatable

[PAHighways]

I-376/US 19/Truck US 19/US 22/US 30 between Exit 69A and 69C has the most multiplexed routes in Pennsylvania.

[Hellfighter]

There's the I-35/I-70/US-24/US-40 and the I-70/US-24/US-40/US-169 multiplexes in Kansas City

[froggie]

The Jackson area has a five-highway multiplex: I-20 & I-55, U.S. 49 & 51 and Mississippi 18 (though 18 is not signed as much).

Minus MS 18, which has a gap in the Jackson area...with both ends at US 80, so that one's a quadruplex.

[Roadgeek Adam]

Here in Jersey,

US 1, US 9, US 46, I-95 approaching the George Washington Bridge.

-----------------------------------------------------------------
Without state routes:

NJ 172 ends at NJ 27, CR 514/CR 527, and Middlesex CR 672 in New Brunswick

[hbelkins]

To my knowledge, Kentucky's honors go to a "fiver" in Pikeville -- US 23, US 119, US 460, KY 80 and KY 1426. All five routes are signed on a short stretch of highway south of the Pikeville Cut-Thru, but Kentucky only officially recognizes one highway on that route, US 23.

[Mr_Northside]

I-376/US 19/Truck US 19/US 22/US 30 between Exit 69A and 69C has the most multiplexed routes in Pennsylvania.

I do believe that general area also has the quirk where North Truck US-19 is multiplexed on the same ramp with South Truck US-19. 
This is because there are no direct ramps to/from the Ft. Pitt Tunnel to/from Saw Mill Run Blvd.
Southbound Truck 19 has to take the Banksville exit, and loop back briefly onto the inbound parkway to get to S.M.R. Blvd.
Northbound Truck 19 has to take the ramp off S.M.R. Blvd towards Banksville (and the outbound Parkway), and use that same loop back to the inbound parkway.

[rawmustard]

A: I-465 on the east side of Indianapolis, IN, between the US-36/SR-67 and US-40 exits, also carries US-31, US-36, US-40, US-52, US-421, SR-37, and SR-67, for a total of 8 routes on one highway...

That should say between US-40 (Washington Ave.) and US-52 (Brookville Rd.) (Exits 46 and 47), because US-40 runs with I-465 to the south of the city and thus wouldn't traverse the Pendleton Road (US-36/SR 67) interchange.

[golden eagle]

The Jackson area has a five-highway multiplex: I-20 & I-55, U.S. 49 & 51 and Mississippi 18 (though 18 is not signed as much).

Minus MS 18, which has a gap in the Jackson area...with both ends at US 80, so that one's a quadruplex.

That doesn't make any sense. I could've sworn, though, that 18 was signed on I-20.

[hbelkins]

Here's a fiver from Mississippi:

[corco]

Wyoming has a ton of 4 way concurrencies- off the top of my head:

I-25 Business/I-90 Business/US-16/US-87 Business in Buffalo
I-25/US-20/US-26/US-87 from Casper to Orin Jct
I-25 Business/US-20 Business/US-26 Business/US-87 Business in Casper
I-25 Business/US-20 Business/US-26 Business/US-87 Business in Douglas
I-25 Business/US-20/US-26/US-87 in Glenrock
I-90 Business/US-14/US-16/WYO 59 in Gillette
I-180/I-25 Business/US-85/US-87 Business in Cheyenne
US-14/US-16/US-20/WYO 120 in Cody
US-14/US-16/US-20/WYO 789 around Greybull
US-26/US-89/US-189/US-191 from Hoback Junction to Jackson

and no 5-way concurrencies. I'm sure I'm missing a couple 4 ways, though

Idaho is probably I-84/US-20/US-26/US-30 from Boise to Mountain Home.

Washington is stuck with a couple 3-ways, I-82/US-12/US-97 around Yakima, I-182/US-12/SR 240 in Kennewick, I-182/US-12/US-395 in Richland, and I-90/US-2/US-395 in Spokane

[golden eagle]

Here's a fiver from Mississippi:

That's the one Bryant was referring to. I've seen it a few times myself.

[froggie]

That doesn't make any sense. I could've sworn, though, that 18 was signed on I-20.

Signed from I-20, but not along I-20.  Both MS 18 segments end at US 80, and there's no overlap with US 80.

Here's a fiver from Mississippi:

Which, prior to the US 45 Meridian bypass being completed in the early 90s, was a sixer in one stretch...east of where that photo was taken.

[jdb1234]

There is a US 43, US 72, AL 13, AL 17, AL 20, AL 157 multiplex in Florence, AL.

[Chris]

Let's not forget the I-44/I-55/I-64/I-70/US-40 multiplex over the Mississippi.

Whether I-44 is part of that is debatable

Why would I-44 be part of that anyway? Does it make sense to extend it into Illinois and let it begin multiplexed? I always thought I-44 ends at I-55 just south of the Poplar Street Bridge.

[hbelkins]

Here's a fiver from Mississippi:

Which, prior to the US 45 Meridian bypass being completed in the early 90s, was a sixer in one stretch...east of where that photo was taken.

On my wife's recent travels, she's been taking road and sign photos for me (and doing quite well, actually). I'm pretty sure she got a photo from the opposite direction at Meridian as well. I'll have to dig that out and post it. I'm still trying to sort through her Massachusetts-to-Ohio photos.