Route Numbering Coincidences

[Road Hog]

Is it a coincidence that AR 59 in NW Arkansas closely parallels US 59 in NE Oklahoma?

[Streetman]

MA/NH 28 was once New England Route 28.

So were a decent number of other routes that don't change across state lines in New England.

One in my neighborhood, CT/MA/NH 10, was N.E. 10. Most likely intentional.

[TheStranger]

The whole NV/CA 266 and NV 264 thing features a mix of "intentionally numbering one route to coincide with the other" and "similarly numbered, but originally unrelated routes" and I know Max R. has a great post about it:

https://www.gribblenation.org/2021/11/california-state-route-266.html

[ozarkman417]

Is it a coincidence that AR 59 in NW Arkansas closely parallels US 59 in NE Oklahoma?

They're close enough to where state/US route shield errors are quite abundant on the Missouri side.

[Indiana_Charter]

IN 6 was replaced by US 6

As much as I've been told this was a coincidence, it just lines up too well with Indiana's grid for me. Same thing with US 36, IN 38, US 40 over in Henry/Wayne counties and US 40, IN 42, IN 44, IN 46 in the Terre Haute/Bloomington area.

[NWI_Irish96]

IN 6 was replaced by US 6

As much as I've been told this was a coincidence, it just lines up too well with Indiana's grid for me. Same thing with US 36, IN 38, US 40 over in Henry/Wayne counties and US 40, IN 42, IN 44, IN 46 in the Terre Haute/Bloomington area.

US 6 runs from Massachusetts to California. I highly doubt it was numbered US 6 just because the Indiana segment was IN 6.

[Indiana_Charter]

IN 6 was replaced by US 6

As much as I've been told this was a coincidence, it just lines up too well with Indiana's grid for me. Same thing with US 36, IN 38, US 40 over in Henry/Wayne counties and US 40, IN 42, IN 44, IN 46 in the Terre Haute/Bloomington area.

US 6 runs from Massachusetts to California. I highly doubt it was numbered US 6 just because the Indiana segment was IN 6.

I know. Since the Indiana grid for the most part predates the US numbered highways, the only part that maybe could have been intentional was a suggestion by Indiana to have its section of US 6 run along IN 6, but even that seems unlikely to me to be on purpose. I know it's a coincidence; I just find it really hard to believe.

[webny99]

I thought of an interesting one the other day:

Starting from NY 19's northern terminus near Lake Ontario northwest of Rochester, following NY 19 south to US 20 east to NY 21 north to its northern terminus forms a nearly perfect boundary around the greater Rochester area. Anything inside 19-20-21 feels like it's distinctly within Rochester's sphere of influence - though there are some pretty rural areas, most of it could be considered "exurban", and I don't think anyone inside that area would deny being from the Rochester area. Though you could argue the sphere of influence extends even further in some directions, anything outside that boundary feels a bit more independent from Rochester even in terms of commuting patterns etc.. while pretty much every town on the 19-20-21 boundary has notable commuter flows to/from the urban core.

And as far as I know it's pure coincidence that three consecutive numbers form this boundary. It'd be even better if the US 20 and NY 5 designations were swapped between NY 19 and Avon to exclude the very rural triangle of land north of US 20 and south of NY 5, but there's no notable population centers there so it's not a big factor either way.

[Bickendan]

US 26 overlaps ORH 26 from Portland to Mt Hood, where they diverge, with ORH 26 going north to Hood River along OR 35, and US 26 to Madras along ORH 53 (but retaining ORH 26's mileposts).

OR 47 briefly overlaps on ORH 47, which follows US 26 from US 101 to Portland.

[freebrickproductions]

AL 14 intersects both AL 140 and AL 147 in two different parts of the state, and I doubt AL 140 and AL 147 were intentionally chosen to match AL 14's number.

[formulanone]

AL 14 intersects both AL 140 and AL 147 in two different parts of the state, and I doubt AL 140 and AL 147 were intentionally chosen to match AL 14's number.

I suppose with SR 14 being a long route, it's bound to happen where routes are mostly sequentially-numbered. Kind of wondered that about 140's loop near Selma, but it's not an old alignment of AL 14. 

SR 10 is border-to-border, but doesn't have any AL 10x route intersections.

I always thought of North Carolina-style SR yyx numbering as "stepchild". Whereas several states use SR yxx numbering are considered "parent-child"

[fillup420]

I always thought of North Carolina-style SR yyx numbering as "stepchild". Whereas several states use SR yxx numbering are considered "parent-child"

There are very few of these "stepchild" route numbers left that still make any sense. Seems they abandoned that numbering scheme long ago. The only two I know of are NC 16 and NC 163 north of Wilkesboro, and NC 18 and NC 181 in Morganton.

[Mapmikey]

I always thought of North Carolina-style SR yyx numbering as "stepchild". Whereas several states use SR yxx numbering are considered "parent-child"

There are very few of these "stepchild" route numbers left that still make any sense. Seems they abandoned that numbering scheme long ago. The only two I know of are NC 16 and NC 163 north of Wilkesboro, and NC 18 and NC 181 in Morganton.

NC abandoned this principle with the great renumbering of 1934.  More examples remain (listing only those that still intersect the parent):

NC 163 is a coincidence (born 1961), as is NC 180 (1952) and NC 241 (1972)

NC 11 and NC 111; also NC 118
NC 18 and NC 182
NC 24 and NC 242
NC 27 and NC 273; also NC 274, NC 275 and NC 279 (renumbering of NC 277)
NC 41 and NC 410; also NC 411
NC 48 and NC 481
NC 56 and NC 561
NC 71 and NC 710
NC 73 and NC 731

Quite a few active 3-digit routes are leftover from that system but their parent routes have been renumbered or dropped from US route overlays...

[GaryV]

The original iterations of Wisconsin 15 and Michigan 15 met at the state border at Marinette and Menominee. They were both replaced by US-41.

This truly was a coincidence, not planned. Both states assigned numbers to their original routes by their length. They were both the 6th longest route in their respective states (counting started at 10).

[bzakharin]

I don't know if it's a coincidence that Burlington/Camden CR 673 is so close, and parallel, to NJ 73.

[Quillz]

CA-139 crosses into Oregon and continues as OR-39. I always wondered if CA-139 was deliberately numbered this way.

However, what I find strange is California already had a history of shuffling around numbers to maintain border consistency. For example, original CA-28 was renumbered to CA-128 so the highway along the north shore of Lake Tahoe could be CA-28 and continue onward as NV-28.

If the intent was to create something similar, then I'm not sure why the original CA-39 (which still exists) wasn't renumbered to CA-139 and then the Susanville-to-Oregon highway wasn't the new CA-39. The fact this didn't happen leads me to believe this is in fact just a happy coincidence. (And much later, CA-168 was truncated just west of Nevada so CA-266 could connect to NV-266 instead).

On US-101, exit 27 is with CA-27. Exit 769 is with CA-169.

CA-197 is just west of US-199, and starting from the coast, you get: 101, 197, 199. This again is likely just a coincidence but it kind of slots in nicely.