What's the most recent new route designation in your state/province?

[thspfc]

For Wisconsin it's WI-195, designated November 2024

[JayhawkCO]

For Wyoming, unless I'm mistaken, it would be WYO344 and WYO346 in 1998 that are the designations for former US87 where it was closed by the landslide.

[Flint1979]

Michigan:
State highway: M-343.

Interstate: I-69 for mainline, I-275 overall.

US highway: US-45 for mainline, US-33 was newer but no longer exists in the state ending in Elkhart, Indiana currently. Business US-131 around Constantine for overall.

[jpi]

Tennessee's newest route currently is TN 690 the by-pass around Union City in northwest TN, it's a temp designation for what will be I-69. As for Pennsylvania, I think PA 760 is newest for state routes and I-295 near Philadelphia as part of I-95's relocation to the eastern edge of the Turnpike. Also PA 297 in my native York County is pretty new too.

[74/171FAN]

The last one I can think of for sure in PA was PA 297 replacing PA 295 in 2018.  I think everything else like the CSVT so far has been realignments of existing routes.

I still think that PA 297 is technically later than the others.

[hbelkins]

Kentucky adds state routes all the time, but the most recent designation I can think of is Interstate 169, which is the former Pennyrile Parkway between the Western Kentucky Parkway (now I-69) and I-24.

[bassoon1986]

Louisiana:

Interstates: unsigned I-910 along business US 90 in New Orleans is the most recent designation in 1999. I-510 on 1992 is the most recent signed Interstate. The most recent addition to the interstate system is I-49 north of Shreveport

The most recent US Route is Bypass US 79 in Homer in 2011

State routes: LA 3242 In St Tammany Parish near Bush in 2024


iPhone

[Quillz]

US 395 Business in Ridgecrest was commissioned by AASHTO in 1989.  That is in fact the newest Business Route approved by AASHTO in California.

And, IIRC, 395 never ran through Ridgecrest at all. So it's a "fake" business route in the sense there was no "old road" in the first place.

[Quillz]

For California, wouldn't the current CA 11 be newer (or CA 7)?

Possibly newer than 241/261 on paper yeah.

I'll edit my post

11 was designated in 1994 (and signed maybe a year or two ago), 7 was designated 1990 and signed 1996

It's still staggering to me that the most populous state and one of the top five in total area last initiated a new route thirty years ago. No matter what your view is on the state of the automobile, that borders on absurd.

Maybe it's because I've lived somewhere that mints new routes every year or two, but also decommissions a few here and there as well.

Alabama SR 304 came about in a letting about 4 years ago, was just signed last year. 

It's because California only signs routes that are state maintained. The moment it stops being state maintained, it stops being a route. Which goes against practical logic. It's very dumb.

I can't say enough times that routes should exit for navigation. The typical motorist does not care who maintains the road. If you need to ensure this information is known, use the miner spade with a different color.

County routes are also rarely signed.

[JayhawkCO]

Colorado:

Interstate: I-76 west of I-25 in 1993

US Highway: US491 renamed from US666 in 2003

State Route: CO21 in 2007

State Route: CO85 in 2025

[Max Rockatansky]

US 395 Business in Ridgecrest was commissioned by AASHTO in 1989.  That is in fact the newest Business Route approved by AASHTO in California.

And, IIRC, 395 never ran through Ridgecrest at all. So it's a "fake" business route in the sense there was no "old road" in the first place.

You're correct in that never was aligned through Ridgecrest.  All the same I think if you're going to look the concept of what a Business Route should be then US 395BL fulfills the requirements.  AASHTO has never had a rule which stipulated that a Business Route needed to be former alignment.  I'm honestly surprised that AASHTO was even consulted by 1989.