What is the most unexpected concurrency?

[I-57/Route 66 Fan]

I would say I-55/I-70/US 40/Great River Road in the eastern St. Louis suburbs, this is unusual because of the fact that the Great River Road is thrown in there.

[NE2]

I-57/Route 66

[kphoger]

Now I wish there were a concurrency in Surprise, AZ.

[I-57/Route 66 Fan]

I-57/Route 66

Now I wish there were a concurrency in Surprise, AZ.

I want one that actually exists.

[flan]

Eastbound and westbound US 60 for one block in Newport News, VA

[SkyPesos]

All of the US and state routes along I-465.

[kphoger]

As for real answers...

TX-130 overlapping I-10 between San Antonio and Seguin, rather than just starting at Seguin.

Taney County 165 being co-signed with MO-165 south of the Strip in Branson, as if that's necessary.

[CoreySamson]

I'm always surprised the I-70/79 concurrency exists. Probably one of the most understated interstate/interstate concurrencies out there.

As for other concurrencies, the fact that TX 70 has a concurrency with I-40 out in the Panhandle always startles me because Texas doesn't really do interstate/state concurrencies (other than the TX 130/I-10 one which was already mentioned). This also means that a section of TX 70 is the most driven part of the TX state highway system on the Travel Mapping website by a whopping 30 or so drivers. As a result, about a third of everyone on TM has traveled a section of TX 70.

[JayhawkCO]

I'll throw out I-41/I-894, as you would have assumed I-894 would have been decommissioned when I-41 was created.

[kphoger]

I'll throw out I-41/I-894, as you would have assumed I-894 would have been decommissioned when I-41 was created.

Good answer.  (Now I sound like we're on Family Feud.)

[NWI_Irish96]

Probably one in Spain. Nobody expected it.

[GaryV]

I-96 and I-275.

I'm pretty sure the concurrency continues to exist, even though any northward extension of 275 has been thoroughly quashed, because the locals know the road as 275 and not 96. That's because all of 275 was completed before the Jeffries Freeway of I-96 from downtown was built.

[kphoger]

Probably one in Spain. Nobody expected it.

Why?  Because nobody expects the Spanish coexistence?

[Declan127]

NY 9A/Henry Hudson Pkwy in NYC, if only because 9A really doesn't have any purpose after it hops on

[PColumbus73]

Conversely, in Chillicothe, OH, a misconception I've always had was that US 50 was officially concurrent with US 23 & 35 because at the Main St exit, signed imply as such.

But actually, US 50 uses Eastern Ave to Bridge St, then to Main St.

I think the I-20/55 concurrency generally goes overlooked.

[gonealookin]

It always seems a little odd to me that there's a concurrency of an Interstate with an Alternate US Route.  We have two of those in this state.

I-80 and US 95 Alternate from Exit 83 to Fernley.

I-80 and US 93 Alternate from West Wendover to Wells.

I don't get too worked up about route numbering generally.  If I were doing the numbering though, I'd drop both of those alternates.  Alternate US 95 south of I-80 would get a Nevada state route number, and Alternate US 93 south of I-80 would get a US x93.

[Max Rockatansky]

Nevada didn't have official approval from AASHO to sign most of those alternated for quite some time.  US 50A in particular kept getting denied until AASHO backed off.  US 95A makes a lot more sense when you consider the original weird jog that US 95 had make between Fernley and Fallon.  The mainline didn't get rerouted until NV 1A north of Fallon was paved in the 1950s.

[gonealookin]

It's the concept of designating an "Alternate" route that nobody would ever drive end-to-end that bugs me more than anything.  And that's the case with all three of those alternates in Nevada:  50, 93 and 95.  Nobody would ever drive from Wells to Ely via West Wendover, for example, nor from Exit 83 to Schurz via Fernley and Yerington.

"Alternate US 395", now that's a legitimate designation, as high-profile vehicles are diverted off the I-580/US 395 freeway between the south end of Reno and the south end of Washoe Valley during strong crosswind conditions.  A better use of the "Alternate US 95" numbering would be the route of US 50 and Nevada SR 361 from US 95 at Fallon to US 95 at Luning, as US 95 west of Walker Lake is also subject to closures.

As to 50A between Fernley and US 50 west of Fallon, it's a well-used connection but fairly short; I'd give it a Nevada state route number.

[Max Rockatansky]

If I recall correctly wasn't 50A more or less born out of the fact that US 50 was originally intended to end in Fernley?  Extending it west to Carson City and California via NV 2A was a last minute addition when the system was formally created in 1926.  2A from everything I've read was pretty haggard well into the World War II era.

[Scott5114]

It's the concept of designating an "Alternate" route that nobody would ever drive end-to-end that bugs me more than anything.  And that's the case with all three of those alternates in Nevada:  50, 93 and 95.  Nobody would ever drive from Wells to Ely via West Wendover, for example, nor from Exit 83 to Schurz via Fernley and Yerington.

This bugged me too, until I started thinking about it and came to the realization that it's probably because Nevada wanted all of its important through highways to be US routes and for state routes to be reserved for secondaries. Abusing alternate US routes was the only way they could make that happen. (There's also the whole thing where they're trying to keep as much of the LV-Reno corridor on the number 95 as possible.)

With the current numbering system, maybe they could give the alternate routes two-digit numbers (51, 94, and 96, maybe?) and imply that they're major highways that way.

It sure doesn't seem like there are a whole lot of people going between Ely and Wendover, so maybe that should just be an ordinary three-digit state route.

[gonealookin]

If I recall correctly wasn't 50A more or less born out of the fact that US 50 was originally intended to end in Fernley?  Extending it west to Carson City and California via NV 2A was a last minute addition when the system was formally created in 1926.  2A from everything I've read was pretty haggard well into the World War II era.

I'd think the 50A designation has more to do with the Lincoln Highway splitting into alternate north and south routes between that junction west of Fallon and Sacramento.

The direct route from Fallon to Carson City is designated US 50 on the 1933 state map, and the 1934 map shows the whole route as fully paved.  https://www.dot.nv.gov/travel-info/maps/historical-maps

In any case, even with the current US 95 north of Fallon not being paved until the late 1950s, I don't see a reason why conditions in the mid-20th century would dictate that we still carry illogical route numbering into 2026.

[Max Rockatansky]

If I recall correctly wasn't 50A more or less born out of the fact that US 50 was originally intended to end in Fernley?  Extending it west to Carson City and California via NV 2A was a last minute addition when the system was formally created in 1926.  2A from everything I've read was pretty haggard well into the World War II era.

I'd think the 50A designation has more to do with the Lincoln Highway splitting into alternate north and south routes between that junction west of Fallon and Sacramento.

The direct route from Fallon to Carson City is designated US 50 on the 1933 state map, and the 1934 map shows the whole route as fully paved.  https://www.dot.nv.gov/travel-info/maps/historical-maps

In any case, even with the current US 95 north of Fallon not being paved until the late 1950s, I don't see a reason why conditions in the mid-20th century would dictate that we still carry illogical route numbering into 2026.

Interestingly Rand McNally captured the original planned terminus of US 50 on their Junior edition maps for 1925:

https://www.davidrumsey.com/luna/servlet/detail/RUMSEY~8~1~2159~200005:Rand-McNally-Junior-Road-Map-Califo?sort=Pub_List_No_InitialSort%2CPub_Date%2CPub_List_No%2CSeries_No&qvq=q:california%20road%201925%3Bsort:Pub_List_No_InitialSort%2CPub_Date%2CPub_List_No%2CSeries_No%3Blc:RUMSEY~8~1&mi=1&trs=5

I misspoke above, the original planned terminus for US 50 was Wadsworth via Fernley.  I have a blog coming up on our page for US 50 in Dayton.  This is the text of what I found regarding NV 2A in the biennial reports:

" Dayton and the Pioneer Branch of the Lincoln Highway would eventually be assigned to the corridor of Nevada State Route 2A.  Nevada State Route 2A originated at Leetville near Fallon and extended westward to Carson City.  The definition of Nevada State Route 2A can be seen in the 1921-1922 Third Biennial Report by the Nevada Department of Highways.

The initial draft of the US Route System was approved by the Secretary of Agriculture during November of 1925.  Originally US Route 50 was not slated to replace the Pioneer Branch of the Lincoln Highway but rather terminate at US Route 40 at Wadsworth, Nevada.   

US Route 50 is shown to have a planned terminus at US Route 40 near Wadsworth, Nevada on the 1925 Rand McNally Junior Map of California. 

US Route 50 can be seen terminating US Route 40 in Wadsworth, Nevada on an October 1925 report to by the Bureau of Public Roads which lists the recommended US Routes. 

https://babel.hathitrust.org/cgi/pt?id=mdp.39015021099604&view=1up&seq=107

The December 1930-June 1932 Eight Nevada Department of Highways biennial reported US Route 50 had been realigned approximately 2 miles east of Mound House towards Dayton.  This realignment bypassed the former alignment through Daney Canyon. 

The 1938-1940 Nevada Department of Highways Biennial listed US Route 50 east of Carson City to Leetville via Dayton as Federal Aid Route 4 for the state.  This designation would see US Route 50 moved onto a bypass of downtown Dayton over the following years.  The Biennial reports to not clearly specify when Federal Aid Route 4 was completed during the 1940s."

[Mapmikey]

The US 15-15A concurrency running from Walterboro SC to Laurinburg NC (165 miles) from about 1936-50.

[gonealookin]

Interestingly Rand McNally captured the original planned terminus of US 50 on their Junior edition maps for 1925:

https://www.davidrumsey.com/luna/servlet/detail/RUMSEY~8~1~2159~200005:Rand-McNally-Junior-Road-Map-Califo?sort=Pub_List_No_InitialSort%2CPub_Date%2CPub_List_No%2CSeries_No&qvq=q:california%20road%201925%3Bsort:Pub_List_No_InitialSort%2CPub_Date%2CPub_List_No%2CSeries_No%3Blc:RUMSEY~8~1&mi=1&trs=5

I guess I'd never thought about some of the early route numbering ideas that were changed prior to implementation.  On that map they have US 60 running along the alignment of what actually became US 66; I suppose when US 66 was created, US 60 was shifted south to run through Blythe rather than Needles.  They also have US 91 running along the modern US 95 routing, and terminating at then-proposed US 60 at the present intersection of US 95 and Goffs Road.

I misspoke above, the original planned terminus for US 50 was Wadsworth via Fernley.

I think you had it right with US 50 terminating in Fernley on the 1925 plan.  Fernley isn't labeled on that map and it's hard to see at that scale, but assuming US 40 ran on Main Street in Fernley, I'd say the end point of US 50 as shown on that map is on the east side of Fernley, at what is now a roundabout where Alternate US 50 intersects Business Loop I-80.

Edit:  OK, that other document specifically says "Wadsworth".  Maybe "Fernley" was subsequently split off from Wadsworth?  The Rand McNally map seems to put the junction 3 miles east of the Wadsworth dot, i.e. at modern-day Fernley, and there's no "Fernley" dot on the Rand McNally map.

[kphoger]

It's the concept of designating an "Alternate" route that nobody would ever drive end-to-end that bugs me more than anything.

I don't like the concept of [Alternate] bannered routes to begin with.  Just give it a real, distinct number.  I feel similarly about letter-suffixed routes, but those are at least supposed to be equally valid options—unlike Alt routes.