Interstates and US routes w/o a duplex within a state

[odditude]

New Jersey:

I-195
I-287
I-76

US 322?

Until the construction's done, I-76's eastern terminus is on a multiplex with I-295.

North of where US 322 splits off of the Black Horse Pike (which continues NB as NJ-42), it's concurrent with CR 536.

...and even more importantly, the eastern ~12 miles of 322 are a concurrency with US 40.

[TheStranger]

I-8

From what I can tell, all of I-8 qualifies (both California and Arizona). Are there any other Interstates or US routes in more than one state where their entire length is not duplexed?

US 163, US 195

Does US 199 still run concurrent with OR 99 in Grants Pass?  I know there's the newer 199 alignment heading directly east from 99 to 5, and Wikipedia suggests that both that route and the older downtown route with 99 are signed as 199.

[NE2]

West Virginia has US 30, US 22, I-470, I-79.

I-79 overlaps US 19. US 22 overlaps WV 2.

[vtk]

US 22 overlaps WV 2.

Damn, missed it by that much.

The body of this post also applies to itself, as I have edited this post to correct the Get Smart catchphrase.

[myosh_tino]

Looking at the posts on the first thread, it seems state route concurrencies also are being considered.  15, 215, 405 all have concurrencies with at least one state route, and 101 has quite a few.

Thus...the Interstate and US routes that completely lack overlapped routes in California:

I-105
I-205
I-505
I-605
I-805
future 905

I-8

I-110
I-210
I-710

I-380
I-780
I-980
I-238

US 6
US 199

I was going to ask about I-680 but forgot that there's an ever-so-brief concurrency with CA-84 in Sunol.  Oddly enough, that concurrency only applies to northbound I-680.  Westbound CA-84 never merges onto southbound I-680.

[admtrap]

Looking at the posts on the first thread, it seems state route concurrencies also are being considered.  15, 215, 405 all have concurrencies with at least one state route, and 101 has quite a few.

Thus...the Interstate and US routes that completely lack overlapped routes in California:

I-105
I-205
I-505
I-605
I-805
future 905

I-8

I-110
I-210
I-710

I-380
I-780
I-980
I-238

US 6
US 199

I was going to ask about I-680 but forgot that there's an ever-so-brief concurrency with CA-84 in Sunol.  Oddly enough, that concurrency only applies to northbound I-680.  Westbound CA-84 never merges onto southbound I-680.

For I-210, pretty sure there's an overlap with CA 2 between the Glendale Fwy interchange and the Angeles Crest Hwy exit.

[TheStranger]

For I-210, pretty sure there's an overlap with CA 2 between the Glendale Fwy interchange and the Angeles Crest Hwy exit.

Thanks for catching that one - I updated my list.

[empirestate]

Well shit, I made a whole list for Interstates in New York and it seems to have gone missing. Oh well, the general takeways were:

—Almost all of the qualifying Interstates are 3dis, the only exception being I-78. And of course, most of the 3dis are too short to be impressive results, except for I-684, I-495, and maybe I-390 (because the NY 15 overlap is no longer official, but there are still signs, so it may not count).

—I-878 may or may not count: it's signed only as NY 878 and not I-878, and it doesn't overlap any other routes. Likewise, I-787 overlaps NY 7, but only where the Interstate is unsigned, so you might not count that.

—Speaking of NY 7, it seems to be the big ruiner here, as it disqualifies not only I-787, but also I-88 and I-890.

—I-90 gets tantalizingly close, with only a teeny overlap with I-87 to disqualify it.

So the winners are:
78
478
678
878 (?)
481
781
684
787 (?)
290
390 (?)
490
590
690
990
295
495
695
895

Did I miss any?

[hotdogPi]

Well shit, I made a whole list for Interstates in New York and it seems to have gone missing. Oh well, the general takeways were:

—Almost all of the qualifying Interstates are 3dis, the only exception being I-78. And of course, most of the 3dis are too short to be impressive results, except for I-684, I-495, and maybe I-390 (because the NY 15 overlap is no longer official, but there are still signs, so it may not count).

—I-878 may or may not count: it's signed only as NY 878 and not I-878, and it doesn't overlap any other routes. Likewise, I-787 overlaps NY 7, but only where the Interstate is unsigned, so you might not count that.

—Speaking of NY 7, it seems to be the big ruiner here, as it disqualifies not only I-787, but also I-88 and I-890.

—I-90 gets tantalizingly close, with only a teeny overlap with I-87 to disqualify it.

So the winners are:
78
478
678
878 (?)
481
781
684
787 (?)
290
390 (?)
490
590
690
990
295
495
695
895

Did I miss any?

There are also some US routes that qualify (US 2 being one of them).

[bzakharin]

Until the construction's done, I-76's eastern terminus is on a multiplex with I-295.

Where?
https://www.google.com/maps/@39.871282,-75.102001,3a,75y,203.9h,90.09t/data=!3m4!1e1!3m2!1sT6l2XnkNFMOVHBSdn7VFyA!2e0
https://www.google.com/maps/@39.871283,-75.101803,3a,75y,353.18h,83.22t/data=!3m4!1e1!3m2!1s70a5eYx-iX3Agm-rJeACMg!2e0

[Pete from Boston]

I-91 in Vermont.

Plus many short ones (most 3dis that are 10 miles or shorter would qualify).

I-91 in Connecticut.  Conn. 15 flanks it in Meriden, but the two do not share pavement. 

[DTComposer]

For I-210, pretty sure there's an overlap with CA 2 between the Glendale Fwy interchange and the Angeles Crest Hwy exit.

Thanks for catching that one - I updated my list.

US 97 in California doesn't have any concurrencies, I believe.

[TheStranger]

US 97 in California doesn't have any concurrencies, I believe.

Isn't it concurrent with Business I-5 on its southernmost mile?

[robbones]

US 271 in Arkansas is the only one that I can think of.

[Bickendan]

US 97 in California doesn't have any concurrencies, I believe.

Isn't it concurrent with Business I-5 on its southernmost mile?

It is. Just had to double check that CA 265 wasn't also in on the action (north half of Bus I-5 only).

[roadman65]

I just remembered that in Florida we have 3 US routes not concurrent with any other US route or interstate.

US 29
US 231
US 331

[hotdogPi]

I just remembered that in Florida we have 3 US routes not concurrent with any other US route or interstate.

US 29
US 231
US 331

Even if that's true, if it's concurrent with a single state route at any point along its length, it doesn't count.

[NE2]

Even if that's true, if it's concurrent with a single state route at any point along its length, it doesn't count.

It counts if that state route is deliberately unsigned.

But US 331 does overlap US 90.

[roadman65]

I just remembered that in Florida we have 3 US routes not concurrent with any other US route or interstate.

US 29
US 231
US 331

Even if that's true, if it's concurrent with a single state route at any point along its length, it doesn't count.

They are not signed here.  Plus secret routes are not actual routes as far as even map makers are concerned hence they leave it off on many editions.

Edit: I did not realize that US 331 did have an overlap with US 90.

[TheHighwayMan3561]

Minnesota's only uncontested winner is US 69. US 65 may or may not count depending on if you count being part of the I-35 business loop in Albert Lea as a duplex.

[hbelkins]

West Virginia has US 30, US 22, I-470, I-79.

Nope. US 22 has a short concurrency with WV 2. And US 19 is concurrent with I-79 from the north end of Corridor L to the Flatwoods exit.

But US 35, on the other hand, had its concurrency with WV 34 removed when it was relocated.



I didn't see where anyone had started a listing for Virginia that includes US routes, but US 219 would be on the short (pun intended) list.

[robbones]

In Mississippi, I-10, I-110 and US 90 along the Gulf Coast are not duplexed with any other highways. In the northern part, US 72 and 78 are by their lonesome, though 78 will become I-22 in the very near future.

I 110 has a concurrency with MS 15 its entire length, unless it was truncated sometime recently.

[davewiecking]

Maryland: I-81, I-97, I-195, I-270, I-370, and I-895 are on their own. I-68 and I-70 dance with US40. I-95 is concurrent with  I-495 on the DC beltway. I-83 is concurrent with I-695 on the Bmore beltway. I-595 is so concurrent with US-50/301 that only people on this Forum know it exists. US50 is concurrent with US301 and US13 at parts. US-29 almost qualifies, but I think it's concurrent with MD410 for a few yards in downtown Silver Spring due to the configuration of the intersection where they cross. US1 shares with things in Baltimore, and with US222 north of that. US 113 is on its own.

[empirestate]

There are also some US routes that qualify (US 2 being one of them).

Yeah, I didn't look at US routes yet. Let's see...

US 2 and US 220 count, obviously. Hard to get an overlap into just a few hundred feet!

US 1 and US 9 come in with I-95, US 4 spends lots of time with NY 32, US 6 rides along NY 17, US 9W, US 11, nope...

US 15 did count until I-99 came along. But now, no...

US 20 has a well-known overlap with NY 5...

Oh, yup, there's one other. Can you guess? It's BUS US 62.

[DTComposer]

US 97 in California doesn't have any concurrencies, I believe.

Isn't it concurrent with Business I-5 on its southernmost mile?

It is. Just had to double check that CA 265 wasn't also in on the action (north half of Bus I-5 only).

True, but are we counting business routes, considering they aren't technically state highways?