Only in these two states...

[TheHighwayMan3561]

froggie: could you be more specific when you say "until recently"? I'm seeing exit tabs in MN that are right/left justified on GSV going back to 2008.

From what I can tell, MnDOT changed their guidance in 2015.  But as recently as 2 years ago (the last time I made it back), center tabs were still plentiful.

The last area with plentiful center tabs is 494 between 394 and Valley View Road, which was rebuilt in 2006 right as right-justified tabs were becoming the norm in the state. There are a few isolated ones around the state, though.

[OCGuy81]

I might be wrong on this but here goes.

CA and WA: only two states that use Freeway Entrance signage at every interchange.

[SkyPesos]

I might be wrong on this but here goes.

CA and WA: only two states that use Freeway Entrance signage at every interchange.

Not sure if it's every interchange, but I found some Nevada examples

[OCGuy81]

I might be wrong on this but here goes.

CA and WA: only two states that use Freeway Entrance signage at every interchange.

Not sure if it's every interchange, but I found some Nevada examples

I knew Nevada used them quite a bit, but I wasn't sure if it was at every ramp. California and Washington seem to

[plain]

CA and VA: only states with both mountain tunnels and underwater tunnels for vehicles

[kphoger]

How many states use a substantially different shield blank for post-mounts as for BGS-mounts?

Texas
New Mexico ??? sort of
Idaho ??? sort of

others?

[vdeane]

Although new NY signs don't do this anymore.

Sure they do.  Lots of newer signs that have it done that way... including the one you linked!
https://nysroads.com/photos.php?route=i90a&state=NY&file=101_3408.JPG
https://nysroads.com/photos.php?route=i390&state=NY&file=102_1153.JPG
https://nysroads.com/photos.php?route=i87a&state=NY&file=102_0590.JPG
https://nysroads.com/photos.php?route=i81&state=NY&file=101_7244.JPG
https://nysroads.com/photos.php?route=i88&state=NY&file=102_1089.JPG

It's certainly true that there are more and more examples of NY signs that don't do that... I suspect the reason is an increasing number of new signs being installed as spot replacements (done by maintenance forces in-house) or design-build projects (designed by the contractor rather than NYSDOT).

(personal opinion)

OK, what state are you saying has uniquely popularized the roundabout?

I wasn't exactly saying that, although I would have guessed Massachusetts, but I also wouldn't have been entirely correct, as Wikipedia says the first modern roundabout in the U.S. was built in Nevada in 1990 (https://en.wikipedia.org/wiki/Roundabout#Development_of_modern_roundabouts).

Is roundabout some strange non-Massachusetts term for rotary?

There actually are differences.  Roundabouts are smaller and lower speed, for one.

CA and VA: only states with both mountain tunnels and underwater tunnels for vehicles

Nope.
https://goo.gl/maps/FLjQX7bkNQ5WrwydA
https://goo.gl/maps/xVRcR4FgB4bNgpFm8

There's also this: https://goo.gl/maps/txx7XeA94q7hBPWp9

[plain]

CA and VA: only states with both mountain tunnels and underwater tunnels for vehicles

Nope.
https://goo.gl/maps/FLjQX7bkNQ5WrwydA
https://goo.gl/maps/xVRcR4FgB4bNgpFm8

There's also this: https://goo.gl/maps/txx7XeA94q7hBPWp9

Oops!

Then I'll try this...

NC and WI: Only states where an interstate multiplexes with a US route with the same number lmao

[mgk920]

Virginia and Wisconsin - the only states with a 'wrong way' pairing of interstate highway route numbers.

Mike

[SkyPesos]

CA and VA: only states with both mountain tunnels and underwater tunnels for vehicles

Nope.
https://goo.gl/maps/FLjQX7bkNQ5WrwydA
https://goo.gl/maps/xVRcR4FgB4bNgpFm8

There's also this: https://goo.gl/maps/txx7XeA94q7hBPWp9

Oops!

Then I'll try this...

NC and WI: Only states where an interstate multiplexes with a US route with the same number lmao

That is true currently, but any confirmation if I-69 will share a concurrency with US 69 in Lufkin in the near future? US 59 does with US 69, on the eastern loop of Loop 287.

[cl94]

I don't think anyone ever said Arizona hadn't planned a 3di.

Hell, Arizona had a 3DI once upon a time. It just became part of a rerouted I-10 in 1971.

[jmacswimmer]

Virginia and Wisconsin - the only states with a 'wrong way' pairing of interstate highway route numbers.

Mike

I-26/I-240 in Asheville NC.  And, technically, I-76/I-80 ever-so-briefly while passing thru the toll plaza at Ohio Turnpike exit 218.

[cl94]

Virginia and Wisconsin - the only states with a 'wrong way' pairing of interstate highway route numbers.

Mike

And, technically, I-76/I-80 ever-so-briefly while passing thru the toll plaza at Ohio Turnpike exit 218.

Officially, the designations swap where the Turnpike crosses the free road, so no concurrency. The swap between I-87 and I-90 in New York is officially a concurrency, but not the similar-looking Ohio case.

[TheStranger]

Virginia and Wisconsin - the only states with a 'wrong way' pairing of interstate highway route numbers.

Mike

I-26/I-240 in Asheville NC.  And, technically, I-76/I-80 ever-so-briefly while passing thru the toll plaza at Ohio Turnpike exit 218.

California has 80/580 on the Eastshore Freeway through Berkeley towards Albany as well.

SM-G973U1

[ethanhopkin14]

I'll play.  I feel like this is wrong, but maybe this is to start the conversation:

Arizona and California:  Only states to have a section of a highway or highways where the carriageways cross over and mimic driving on the left side of the road due to the grade of a mountain pass.

Texas and Missouri:  Only states that extensively marks exit numbers as a tab above the gore sign, on a separate sign as opposed to on the gore sign itself.  I know it shows up in a lot of states, but I have only seen it widespread in those two. 

Extra Credit:  Texas and Massachusetts:  Only states in the US in which high school football is played under NCAA rules.   

[FrCorySticha]

I might be wrong on this but here goes.

CA and WA: only two states that use Freeway Entrance signage at every interchange.

MT has been putting these up throughout the state. Not sure if on every entrance, but I have seen them on pretty much every one I can think of.

[CoreySamson]

I was going to say that Colorado and Texas were the only 2 states to refer to their state highways as SH-xx, but it turns out Idaho does too.

[Great Lakes Roads]

I might be wrong on this but here goes.

CA and WA: only two states that use Freeway Entrance signage at every interchange.

MT has been putting these up throughout the state. Not sure if on every entrance, but I have seen them on pretty much every one I can think of.

Add West Virginia to that list.

[hbelkins]

ARGUMENT TIME

Which two states' panhandles actually deserve to be called panhandles?

Florida and Oklahoma. Is there even more than two options?

West Virginia's eastern panhandle.

[CNGL-Leudimin]

Minnesota and Texas: Only states currently with Interstate splits (Oddly, I-35 splits in both).

[6a]

What is a "bump" ?

[TheHighwayMan3561]

What is a "bump" ?

Where Route A and Route B meet and swap alignments. For example, Route A comes from the north and turns east at the intersection. Route B comes from the west and turns south.

[TheHighwayMan3561]

ARGUMENT TIME

Which two states' panhandles actually deserve to be called panhandles?

Florida and Oklahoma. Is there even more than two options?

West Virginia's eastern panhandle.

Also Texas, though the region containing El Paso makes more sense to be called a "panhandle" than the Amarillo portion that is the official panhandle.

[Road Hog]

Texas and Missouri:  Only states that extensively marks exit numbers as a tab above the gore sign, on a separate sign as opposed to on the gore sign itself.  I know it shows up in a lot of states, but I have only seen it widespread in those two.

Texas now signs exit numbers on the gore sign. If you still see a tab, that sign is at least 7 years old. Missouri was the first place I saw tabs in the 1980s (it certainly happened before).

[SkyPesos]

Texas and Missouri:  Only states that extensively marks exit numbers as a tab above the gore sign, on a separate sign as opposed to on the gore sign itself.  I know it shows up in a lot of states, but I have only seen it widespread in those two.

Texas now signs exit numbers on the gore sign. If you still see a tab, that sign is at least 7 years old. Missouri was the first place I saw tabs in the 1980s (it certainly happened before).

Think both states moved on from the tabbed exit gore signs. Don’t know much about TX’s, but the most recent ones installed in MO afaik are on MO 364 for exits 12 WB, 14, 17, and 19 EB. MO switched to the vertical style exit gore signs, similar to what MN uses, with a couple of the official MUTCD style for 1-2 digit exit numbers.