State Routes signed like 3di

[bassoon1986]

Louisiana's system doesn't do this either. There is a LA 471 that branches off of US 71 near Colfax, but I think it is coincidental. 471 is an old routing of US 167, but that would have been before the 1956 renumbering.

[SkyPesos]

Bumping this old thread because I wanted to make one titled "3 digit state routes with a US route parent", but this one is pretty much my thread idea, but more inclusive.

For state routes that are signed and act like 3di, my 3 examples already have been mentioned: MO 364, MO 370 and CO/E 470

Missouri is full of 3 digit state routes with a US route parent. MO 340 seems like a spur for US 40, both MO 267 and MO 367 seem like spurs for US 67. Not sure if MO 366 is a spur or just a former alignment of US 66; I heard conflicting reports of whether US 66 used Manchester Rd or Watson Rd through St. Louis, and Google Maps label both as Historic US 66. There's also MO 163 and MO 763 for US 63, and MO 740 for US 40 in Columbia.

Meanwhile, Ohio's examples are mostly used as interstate highway connectors from US routes. OH 435 connects US 35 to I-71, OH 450 connects US 50 to I-275, and OH 420 connects US 20 to I-80/90/280. There's also OH 835, which acts like a business loop of US 35 for what looks like Beavercreek (???).

[NWI_Irish96]

If you're talking about freeways only, IN 912 and IN 641 are the only ones that would qualify, and maybe IN 265 though that's really an extension of a 3di that already exists and should be going away soon anyway.

If you remove the freeway requirement, every 3 digit state highway in Indiana has some similarities to 3di in that their number is based on a parent 2-digit route, but without the even/odd distinctions, and the requirement to connect as many run parallel (114 is a route parallel to 14 and 16 that is between them)

[ilpt4u]

When ISTHA took over the Elgin-O'Hare Expressway and made it the Elgin-O'Hare Tollway, the roadway also got a route number from IDOT: IL 390. Fits the theme, here

That adds to the other 2 Illinois examples that had already been listed in IL 255 and IL 394

IL also has 3 digit state routes that are children of US routes: IL 250, IL 251, IL 267, IL 351, IL 336. IL 145 is debatable whether it is a child of US 45 in Southern IL - as it is located in the region of the state that has 14x numbered state routes. Not sure about IL 140 in relation to US 40 - close enough to make me wonder...

Of those, IL 336 should probably be deleted, since its current routing is 100% multiplexed - and its planned independent section, between Macomb and Peoria, has basically been cancelled. The stub of future never-IL 336 off I-474 west of Peoria is the only section of the "independent"  section that got built

[bing101]

CA-905 in California is signed like a 3di due to its connection to I-5 in San Diego.

[sprjus4]

Not a 3di, but NC-74 Winston-Salem Beltway in North Carolina.

Once it is connected to US-52 north of Winston-Salem and I-74 southwest of the city, it will be redesignated as I-74.

[US71]

IA has SR 471 which follows former US 71 between US 20 and IA 175  near Early.  Both ends connect to US 71

Arkansas had a SR 471 from Rogers to Fayetteville, but it was renumbered.

MO 360 runs from I-44 to US 60

AR 365 is old US 65 but acts more like a "465" since both ends connect to US 65 (addendum: the north terminus is US 65B)

AR 367 follows old US 67, again more like a "4xx".

MO 571 runs from I-49 to I-49 at Carthage.

MO 371 St Joseph could be a 3d on a technicality, but it no longer connects to US 71 at either end.

May be others, but drawing a blank

[thspfc]

WI-441 instantly comes to mind. WI-794 also but it's not a freeway and its number is more based off the 3di of the same name.

[mgk920]

CA-905 in California is signed like a 3di due to its connection to I-5 in San Diego.

Ditto CA 110 and CA 210 v. I-10.

In an earlier posting that I made in this thread, I forgot WI 312 in Eau Claire, WI.  Its west end is at US 12 on the city's west edge.

Mike

[ztonyg]

AZ 51 stems from a previous I-510 proposal (although the segment that connects to I-10 is not built to interstate standards).

[CardInLex]

Kentucky's four digit routes do this (at least newer 4 digits). But, it is not always consistent.

[GaryV]

Michigan has no freeway examples at any level. M-294 connects to I-94, but it's not a freeway. Future M-231 is named after the nearby US 31 freeway and may eventually become a freeway itself.

Since this thread has been revived, I'll also mention a few in Michigan.  Relatively new M-343 is now a spur of M-43.  It used to be part of M-43.

Close-but-no-cigar:

M-227 partly is what used to be Bus US-27, which in itself was US-27 before the freeway was built.  Of course, US-27 no longer exists in Michigan.

M-247 used to be part of M-47.

[hotdogPi]

By complete coincidence: NH 101 and US 1. If US 101 didn't already exist, a few people on this forum would be calling for it to be upgraded (and extended over NH/VT 9 past its terminus so that it's not intrastate).

[TheStranger]

Not counting 905/210/110...
California examples of derivative routes:

Route 330 (former Route 30)
Route 371 (former Route 71)
Route 242 (former Route 24)
Route 46 (former US 466), not a 3 digit route, but still derivative of its former designation

[TheHighwayMan3561]

Wyoming 585 appears on the surface like it was numbered as a spur between US 85 and Sundance.

[Revive 755]

Wisconsin has WI 794, which is just an extension of I-794.

Technically one would be correct on the WI-794, however that is not a full freeway   It was intentionally signed such due to opposition to freeway being built forced it to be built as a parkway.  The route designation extends all the way to College Ave (CTH-ZZ) though the parkway ends at Pennsylvania just a block south of Layton Ave.  This is a scaled back plan that got shot down that had the Interstate extending to Racine and Kenosha.

And possibly down to the Edens Spur/Mainline Edens interchange in Illinois had the upgrades and new alignment near the Wisconsin border not been cancelled.

Once in a while IDOT maps will still show a proposed corridor for what is probably the 794 corridor tying into the US 41 interchange at the north end of the Tri-State.  Sheet 6 of 7 of this plan set from the November 2020 Letting is one example.

[ET21]

Since this was resurrected, you can add IL-390 to this list

[kphoger]

When ISTHA took over the Elgin-O'Hare Expressway and made it the Elgin-O'Hare Tollway, the roadway also got a route number from IDOT: IL 390.

Since this was resurrected, you can add IL-390 to this list

Noted.

[DJ Particle]

MN-610

[mgk920]

Also WI 318, running from US 18 on the west edge of Waukesha, WI due northward to I-94.

Mike

[TheGrassGuy]

By complete coincidence: NH 101 and US 1. If US 101 didn't already exist, a few people on this forum would be calling for it to be upgraded (and extended over NH/VT 9 past its terminus so that it's not intrastate).

...and NY-7, and northern PA-29...

[bing101]

CA-710 located near the CA-134@I-210 interchange is a state route but was originally going to be part of I-710 to Long Beach.


CA-380 (Proposed) was supposed to connect to I-380 in San Bruno.

[ilpt4u]

CA-710 located near the CA-134@I-210 interchange is a state route but was originally going to be part of I-710 to Long Beach.


CA-380 (Proposed) was supposed to connect to I-380 in San Bruno.

California also has the opposite of this thread's title: A 3di numbered like a State Route - We love you, I-238!

[roadman65]

MO Route 370.

[Voyager75]

AL-759 in Gadsden, AL. A small continuation of I-759 at its east end. Signed as AL-759 since the Interstate is planned to be extended to US-431 at some point. The latest plan has it being built as a parkway connector and not a interstate to get more funding for it. It may just be a permanent AL-759 if that's the case.

The segments of the Birmingham Northern Beltline (I-422) will be signed as AL-959 I believe until it's finished in the year 2245.