The most highways multiplexed together?

[Chicagosuburban]

I can't really find anything higher than a triplex around Chicagoland, but on Wikipedia there is an example of a six-highway multiplex (I-40, Business I-85, US-29, US-70, US-220, US-421)

What is the most highways that you've seen multiplexed together?

[agentsteel53]

behold the octoplex.

[huskeroadgeek]

I believe it is unsigned, but a short portion of I-465 on the E side of Indianapolis has I-465 and US 31, 36, 40, 52, 421 and IN 37 together. The biggest signed multiplex I know of is US 56/64/287/412 and OK 3 together at Boise City, OK.

[huskeroadgeek]

behold the octoplex.

How old is that picture? I'm guessing 60s, based on the cars.

[dfilpus]

The six-plex in North Carolina is no more. US 421 was moved to multiplex with I  85 and 1 73. It is still a 5-plex of I 40, I 85 Business, US 29, US 70, US 220.

[Chicagosuburban]

behold the octoplex.

Yeah, I think some of those were re-routed on to expressways.
How old is that picture? I'm guessing 60s, based on the cars.

Yeah, I think some of those were re-routed on to I-69 and I-469

[mukade]

I believe it is unsigned, but a short portion of I-465 on the E side of Indianapolis has I-465 and US 31, 36, 40, 52, 421 and IN 37 together. The biggest signed multiplex I know of is US 56/64/287/412 and OK 3 together at Boise City, OK.

For Indy, also SR 67 so it carries eight routes. I-69 would make the 9th.

[mukade]

Yeah, I think some of those were re-routed on to I-69 and I-469

Only US 27 goes through downtown Fort Wayne now:
- SR 1 from the south ends at I-469 on the south side and starts up at I-69 on the north
- SR 3 from the south ends at US 224 in Markle and starts up at I-69 (Lima Rd)
- SR 14 from the west ends at I-69 (Illinois Rd.)
- SR 37 from the south ends ats at SR 9 in Marion and picks back up at I-469 going to the Ohio line
- US 24 follows I-469 south leg and I-69 to Jefferson Ave.
- US 30 follows I-469 north leg and I-69 to Goshen Rd.
- US 33 follows I-469 south leg and I-69 to Goshen Rd.

[mjb2002]

I've seen a six-plex in Augusta, Ga. US 1/25/78/278 and GA 10/121

[NE2]

Seven signed in Folkston, GA: http://www.gribblenation.com/papics/outofstate/gatotempole-folkston.jpg

[Scott5114]

I believe it is unsigned, but a short portion of I-465 on the E side of Indianapolis has I-465 and US 31, 36, 40, 52, 421 and IN 37 together. The biggest signed multiplex I know of is US 56/64/287/412 and OK 3 together at Boise City, OK.

Boise City isn't signed in the sense of there being an assembly that lists all of them. Rather, the routes all multiplex through a traffic circle around the Cimarron County Courthouse. Once you get in the circle though all the routes are signed at their exit from the circle.

[Stratuscaster]

I can't really find anything higher than a triplex around Chicagoland, but on Wikipedia there is an example of a six-highway multiplex (I-40, Business I-85, US-29, US-70, US-220, US-421)

What is the most highways that you've seen multiplexed together?

The "quadroplex" of I-80/I-94/US-6/US-41 exists just east of the IL/IN state line.

[hbelkins]

Kentucky's champion is five -- US 23, US 119, US 460, KY 80 and KY 1426 just south of Pikeville.

For West Virginia, don't know of more than four, which happens twice in Elkins -- US 33, US 219, US 250 and WV 92, and then US 219, US 250, WV 55 and WV 92.

[Chicagosuburban]

I can't really find anything higher than a triplex around Chicagoland, but on Wikipedia there is an example of a six-highway multiplex (I-40, Business I-85, US-29, US-70, US-220, US-421)

What is the most highways that you've seen multiplexed together?

The "quadroplex" of I-80/I-94/US-6/US-41 exists just east of the IL/IN state line.

Oh yeah I forgot about that one. I still don't think there are any quadroplexes on the Illinois side though.

[kharvey10]

Monstrous St. Louis Multiplex by Will Weaver, on Flickr

That same section used to be just I-55/70, IL 3, US 40/50/66 until the mid 1980s, when US 50 was realigned to I-255 and US 66 was decommissioned.  (I-64 ended at I-55/70.)

PS: this same section will have two route numbers removed in the coming years, when both I-70 and IL 3 will be put on new (separate) alignments.

Just for good measure, the west end of the Poplar St. Bridge at the split back in 1983 had this:

US 40 Westbound (Missouri) at I-55 SOUTH: I-44 WEST, I-70 WEST & Memorial Drive - (1983) by poundsdwayne47, on Flickr

[jdb1234]

In Alabama, it is the US 43, US 72, AL 13, AL 17, AL 20, and AL 157 multiplex in Florence.  AL 2 also runs through here but is hidden under US 72.

[formulanone]

I would imagine the Orlando area has Florida's multiplex champ, somewhere along the Orange Blossom Trail between SR 50 and US 192.

So that's US 92 (SR 600), US 441 (SR 500), and US 17. Five, but just three signed.

I suppose US 1/23/301 north of Callahan gets secret numbers 5 and 15, as well...but also only three signed.

At the corner pocket of the nation, there's not much to connect to, and multiplexed state routes are rare.

[ftballfan]

I can't think of any triplexes in Michigan. There used to be one on the west side of Lansing (I-69, I-96, US-27) until US-27 was truncated all the way to Fort Wayne, IN. In the Hastings area, M-179 is a logical western extension of M-79 that is signed as a different state highway to avoid a triplex (M-37 and M-43 are duplexed through Hastings).

[dfilpus]

I can't think of any triplexes in Michigan. There used to be one on the west side of Lansing (I-69, I-96, US-27) until US-27 was truncated all the way to Fort Wayne, IN. In the Hastings area, M-179 is a logical western extension of M-79 that is signed as a different state highway to avoid a triplex (M-37 and M-43 are duplexed through Hastings).

US 2, US 41, MI 35 from Escanaba to Gladstone
US 2, US 441, MI 95 in Iron Mountain

[InterstateNG]

You mean US-141

More Michigan:

M-72, M-66, US-131 in Kalkaska
M-72, M-37, US-31 in Traverse City

I-55 at various points in the Memphis area is joined by I-40, and US routes 61, 63, 64, 70 and 79, although I'm pretty sure just the interstates are signed.

[ftballfan]

Forgot about all of those (especially the ones in Kalkaska and TC as I've been on both of them).

I possibly found another one. I-94, US-127, M-50 around Jackson (M-50 may still go through Jackson).
There is also BL I-94, M-37, M-96 on the west side of Battle Creek.
If M-50 goes through Jackson, then there is BL I-94, BUS US-127, and M-50 in downtown Jackson.

I-75, US-10, and US-23 used to have a long triplex from Bay City to Flint.

[Truvelo]

behold the octoplex.

How old is that picture? I'm guessing 60s, based on the cars.

One thing about American street scenes is it's hard to date the picture had it not been for the cars. Things like signs and streetlamps are still the same as those fitted in the 60's. The standard Cobrahead lantern has hardly changed.

[NE2]

I would imagine the Orlando area has Florida's multiplex champ, somewhere along the OBT (US 92, 441, 17). At the corner pocket of the nation, there's not much to connect to, and multiplexed state routes are rare.

Nothing overlaps OBT, so I doubt it. There used to be US 1/US 17/US 90/SR 228 in Jacksonville, but that's now all triples with the recent rerouting. It's possible that there are no quadruples in Florida (not counting routes that are normally unsigned, like US 98/US 441/SR 15/SR 700).

[3467]

The Quadplex on the Monmouth Illinois bypass. US67,US 34,Illinois 164 and the Chicago-Kansas City Illinois 110

[Brandon]

^^ I have a hard time taking IL-110 seriously.  IMHO, the signs will not be replaced when they finally fall off their posts.