States with all types of concurrencies among statewide route systems

[D-Dey65]

New York:
-Interstate/US: I-95/US 1

And US 9 from the GWB to Broadway.

-Interstate/State: I-88/NY 28

Also, I-84/NY 52.


Florida is loaded with them, including some hidden ones, and possible hidden ones. For example, I'm not entirely certain about FL 44 and Citrus and Sumter CRs 470.

[ilpt4u]

County routes don't run concurrent with anything else in Illinois.  But Illinois DOES have tollways with Interstate designations, and even a state route concurrent with a tollway (I-88/IL-56).

One example each of the common concurrency types:
Interstate/Interstate: I-80/I-294
Interstate/US: I-39/US51
Interstate/State: I-290/IL-53
US/State: US67/IL-100
US/US:  US24/US136
State/State:  IL-47/IL-176

ISTHA also has a US Route multiplexed on a tollway...the Northern IL end of US 51 (with I-39) merges into the Jane Addams Tollway and I-90, to reach Wisconsin and points North

IL has examples of Interstate/US/IL Multiplexes, as well, such as I-255/US 50/IL 3, I-72/US 36/IL 110, and I-55/I-64/US 40/IL 3

[Max Rockatansky]

Arizona

I-10/US 95

I-10/US 191

I-17/AZ 89A

[vdeane]

New York:
-Interstate/US: I-95/US 1

And US 9 from the GWB to Broadway.

-Interstate/State: I-88/NY 28

Also, I-84/NY 52.


Florida is loaded with them, including some hidden ones, and possible hidden ones. For example, I'm not entirely certain about FL 44 and Citrus and Sumter CRs 470.

Wasn't aiming to be comprehensive, just listing what was off the top of my head.  Were we to try to be comprehensive for NY, we'd be here all day.

[renegade]

US-2 and US-41
also US-2 and US-141

I knew there was one in the UP, I just couldn't find it.  I thought it was 41/141, but I think that is in Wisconsin.

Also, US-10/127 north of Clare and US-23/223 in far southern Monroe County in the Lower Peninsula.

[DandyDan]

In Iowa, you can get all of them except for the Interstate/Interstate concurrency just by following IA 27, the Avenue of the Saints.
Interstate/Interstate I-35 & I-80
Interstate/US I-380 & US 218
Interstate/State I-380 & IA 27
US/US US 218 & US 34
State/State IA 27 & IA 58
US/State US 218 & IA 27

[Buck87]

a few Ohio examples...

Interstate/US: I-70 & US 40, I-475 & US 23

Interstate/State: I-90 & OH 2, I-70 & OH 4

US/State: US 20 & OH 18, US 23 & OH 104 and many more

There are also multiple examples for State/State, US/US, and Interstate/Interstate

[ilpt4u]

a few Ohio examples...

Interstate/US: I-70 & US 40, I-475 & US 23

Interstate/State: I-90 & OH 2, I-70 & OH 4

US/State: US 20 & OH 18, US 23 & OH 104 and many more

There are also multiple examples for State/State, US/US, and Interstate/Interstate

The Buckeye State does have the uncommon 3DI concurrency in Cleveland, I-271/I-480

[ftballfan]

I'll take a stab at Michigan, although I am no expert on the highway system:
Interstate/Interstate: I-69/96, I-69/94
Interstate/US Highway: I-75/US 23
Interstate/State Route: I-96/M-37
US Highway/US Highway:  None that I know of
US Highway/State: US 131/M-46
State/State: M-40/M-89

US-10 is concurrent with both US-31 and US-127 (and was formerly concurrent with US-23 and US-24)

[Bruce]

Off the top of my head (and closest to Seattle)

Washington:

IH/IH: None so far
IH/USH: I-90 and US 97 near Cle Elum
IH/SR: I-405 and SR 900 in Renton
USH/USH: US 2 and US 97 near Wenatchee
USH/SR: US 97 and SR 20 from Okanogan to Tonasket
SR/SR: SR 161 and SR 167 in Puyallup

Oregon (and non-legacy examples):

IH/IH: None so far; I-84 and I-205 run parallel in Portland, though
IH/USH: I-84 and US 30; I-84 and US 395
IH/SR: I-5 and OR 99/99E; I-5 and OR 138
USH/USH: US 26 and 97
USH/SR: US 197 and OR 216
SR/SR: OR 211 and 224

[bulldog1979]

Michigan previously had I-296/US 131/M-37 in Grand Rapids when the rest of I-296 opened in 1962.

Turning to overlaps with county highways:
Interstate/County: none of which I'm aware
US/County: US 131/C-48 at Boyne Falls
State/County: M-123/H-40 at Trout Lake plus at least 3 others
County/County: C-66/C-77 at Cross Village, B-35/B-72 at Ravenna

[bzakharin]

New Jersey has I-295/CR 551. Beat that.

(Minnesota used to have I-35W/CR 62.)

Otherwise in NJ,
Interstate / US overlaps are common on bridges leaving the state (I-295/US 40, I-676/US 30, I-95/US1&9&46), but are otherwise uncommon. The only exceptions I can think of are I-295/US 130 and I-78/US 22

Other types of overlaps are quite a bit rarer. State routes don't tend to overlap with either US routes or Interstates. Off the top of my head US 9 has a concurrency with NJ 35, and I-78 has a concurrency with NJ 139


County Routes tend to overlap with state and US routes, especially those under county maintenance. And then there is CR 551 as mentioned above.


As for multiple roads of the same type overlapping, county routes and US routes do this frequently, while state and Interstate routes not at all (correct me if I'm wrong)

[US 89]

Utah doesn’t have much of a county route system to begin with (hell, most counties don’t even have them), but there’s at least one example of every other concurrency possibility. However, they may not always be signed, particularly for anything involving state routes.

Interstate/interstate: there are two, 15/80 and 15/84, both of which are very well signed.

Interstate/US: several examples, but signage can vary greatly. Some are very well signed, like 70/89. Some have decent signage, like 15/6 and the southern 15/89. Some have very little signage, like the northern 15/89. And some have no signage at all, like 80/189. There is a “quadruplex” of I-70/US 6/50/191, but only I-70 is signed.

Interstate/state: only two examples, neither of which have any signage whatsoever. I-15/SR 30 and I-84/SR 30.

US/US: several examples, almost all of which have great signage. The exception is 40/189, but most of that has been fixed (they still need to sign 189 in Heber and from the exits on the freeway segment, but at least the End 189 sign is gone now).

US/state: US 89/SR 30 (plus US 91 for a short segment) is the only one. It isn’t signed either, though there is some signage in Logan that hints at its existence.

State/state: three examples exist that I can think of — 118/120, 68/48, and 68/85. None are signed, but there is some implied concurrency signage in some cases (but in other cases, there may even be an END sign posted, like where 85 west/north meets 68).


EDIT: forgot about US 89/SR 71. The concurrency is inventoried as SR 71 and is signed as such. There is no mention of US 89 from I-15, much less any guidance that you’re supposed to go east on 123rd. Same story if you’re coming from the north. US 89 just disappears, and all you see are SR 71 and I-15 signs. No signage whatsoever that you’re supposed to go west on 71 and then south on 15.

[Buck87]

a few Ohio examples...

Interstate/US: I-70 & US 40, I-475 & US 23
Interstate/State: I-90 & OH 2, I-70 & OH 4
US/State: US 20 & OH 18, US 23 & OH 104 and many more

There are also multiple examples for State/State, US/US, and Interstate/Interstate

The Buckeye State does have the uncommon 3DI concurrency in Cleveland, I-271/I-480

Yep, which gives Ohio all 3 possible combinations of interstate concurrencies:

2DI/2DI: 80/90, 76/77, 70/71, 71/75
2DI/3DI: 74/275
3DI/3DI: 271/480

Interesting that all 8 of the 2DI's that enter Ohio have a concurrency somewhere in the state

[jon daly]

Utah doesn't have much of a county route system to begin with (hell, most counties don't even have them)...

CT and RI don't have them and I'd be surprised if any New England state does. I was surprised when I saw that NJ has them. NY, I think, has some too, but I found that less surprising given the rural nature of some areas of the Empire State.

[hotdogPi]

Utah doesn't have much of a county route system to begin with (hell, most counties don't even have them)...

CT and RI don't have them and I'd be surprised if any New England state does. I was surprised when I saw that NJ has them. NY, I think, has some too, but I found that less surprising given the rural nature of some areas of the Empire State.

(alpsroads)

Maynard, MA. This is the only county route shield in New England, and it's for MA 27; the sign is erroneous.

[Bickendan]

Off the top of my head (and closest to Seattle)

Washington:

IH/IH: None so far
IH/USH: I-90 and US 97 near Cle Elum
IH/SR: I-405 and SR 900 in Renton
USH/USH: US 2 and US 97 near Wenatchee
USH/SR: US 97 and SR 20 from Okanogan to Tonasket
SR/SR: SR 161 and SR 167 in Puyallup

Oregon (and non-legacy examples):

IH/IH: None so far; I-84 and I-205 run parallel in Portland, though
IH/USH: I-84 and US 30; I-84 and US 395
IH/SR: I-5 and OR 99/99E; I-5 and OR 138
USH/USH: US 26 and 97
USH/SR: US 197 and OR 216
SR/SR: OR 211 and 224

Also: I-5 and US 30
I-82 and US 395
I-405 and US 30
I-84, US 30 and US 395
I-105 and OR 126
I-205 and OR 213
US 20 and US 395
US 20 and US 26
US 26 and US 395
US 30 and US 197
US 20 and OR 126
US 30 and OR 35
US 97 and OR 126
US 395 and US 730
US 20, US 26 and OR 201
US 395 and OR 140
US 97B and OR 39 (two discrete instances)
US 101B and OR 202
OR 18 and OR 22
OR 18 and OR 99W
OR 39 and OR 140
OR 99 and OR 126 and OR 126B
OR 212 and OR 224
OR 99 and CR 389

[ilpt4u]

Interesting that all 8 of the 2DI's that enter Ohio have a concurrency somewhere in the state

I believe only I-88 and I-24 of the 12 IL 2DIs lacks an Interstate concurrency somewhere in the state...
I-88: unless you want to call the Mile-ish long parallel segment where I-355 was built on I-88's ROW a concurrency...But the 2 Tollways never merge, just the 4 carriageways separated by Jersey Barriers before I-355 goes under I-88 at the Western end of the parallel segment
I-24: unless you want to call the continuation of the route to STL from Nashville a "Silent" concurrency on I-57 and I-64

Otherwise
I-39/90
I-55/64
I-55/70
I-55/72
I-55/74
I-57/64
I-57/70
I-74/280
I-80/94
I-80/294
I-90/94

[froggie]

CT and RI don't have them and I'd be surprised if any New England state does.

County routes, no.  But Maine does have county roads that are unnumbered to the layman.

[achilles765]

I know this is three years old, but I just ran across it and wanted to add in:
Texas:
Several examples

Interstate 35 and interstate 410 in San Antonio

Interstate 10 and Us 90 multiple times; including all the way through Houston, though 90 is unsigned.

US 290/SH 6

Beaumont has a couple of miles of road that carries (and is signed) Interstate 10/US 90/US 69/US 96/US 287

And San Antonio seems to have a lot. Like an inordinate amount of them.
There's interstate 37/US 281
Interstate 35/Interstate 410
Interstate 10/US 90
Interstate 10/US 87
Interstate 10/Interstate 35/US 87
Interstate 410/SH 16
Interstate 410/SH 16/SH 130
Interstate 10/US 90/SH 130
Interstate 410/US 281/SH 130

And I'm probably missing a few too

[SkyPesos]

All of Missouri's 2di except I-57 and I-72 have some part concurrent with another interstate.
I-29: I-35, I-435
I-35: I-70, I-29
I-44: I-49, I-55
I-49: I-44
I-55: I-44, I-64, I-70 (formerly)
I-64: I-55, I-70 (formerly)
I-70: I-35, I-55 (formerly), I-64 (formerly)

As for other examples in Missouri...
I/US: I-64/US 40
I/SR: I-35/MO 110
US/US: US 61/US 67
US/SR: US 36/MO 110
SR/SR: MO 94/MO 364

Not sure if there are any concurrencies with state secondaries.