Only in these two states...

[BrianP]

California and Vermont: Green state route shields (if we're considering states only)

South Dakota says hi.

So does MD.  Though it is rare.  And it's just for business/bypass routes.

[formulanone]

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.

Does Alabama no longer do this?  Used to be widespread there, but I haven't been to the state in 12 years.

I can only think of a handful of these remaining within Alabama, and other than Exit 3 on I-565, I'm stumped as to exactly where they're still posted.

[Big John]

^^ Georgia signs for SR 520 has green border.

[jakeroot]

Update to the centered exit tab WA/OR pairing:

WA is now a party of one with its centered exit tabs. Some new signs dotted around the Portland metro, much to my surprise surfing the freeways on GSV, show left and right justified exit tabs. Examples here and here (both installed within the last five years). I also checked other exits outside the Portland metro; the practice extends to multiple ODOT districts based on this exit sign in Eugene. So it would seem to be a state-wide thing at this point.

So, here's a list:

States that still use centered exit tabs/justification: WA

States that have used centered exit tabs/justification but do not anymore: OR, CA, GA, CT, MO, MN (others maybe?)

[NoGoodNamesAvailable]

Wyoming and New York: only states to use box beam guard rail extensively

[SkyPesos]

Update to the centered exit tab WA/OR pairing:

WA is now a party of one with its centered exit tabs. Some new signs dotted around the Portland metro, much to my surprise surfing the freeways on GSV, show left and right justified exit tabs. Examples here and here (both installed within the last five years). I also checked other exits outside the Portland metro; the practice extends to multiple ODOT districts based on this exit sign in Eugene. So it would seem to be a state-wide thing at this point.

So, here's a list:

States that still use centered exit tabs/justification: WA

States that have used centered exit tabs/justification but do not anymore: OR, CA, GA, CT, MO, MN (others maybe?)

With WA's center full length exit numbers, how are left exits signed? Do they just stick a yellow "LEFT" banner left of the exit number on the full length thing?

[US 89]

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

Texas
New Mexico
Idaho ??? sort of

others?

New Mexico definitely qualifies - the BGS mount is a simple circle while the individual shield has the Zia sun. Idaho now uses the same blank for all applications with their recent shield redesign.

Also, add South Carolina to the list.

[jakeroot]

Update to the centered exit tab WA/OR pairing:

WA is now a party of one with its centered exit tabs. Some new signs dotted around the Portland metro, much to my surprise surfing the freeways on GSV, show left and right justified exit tabs. Examples here and here (both installed within the last five years). I also checked other exits outside the Portland metro; the practice extends to multiple ODOT districts based on this exit sign in Eugene. So it would seem to be a state-wide thing at this point.

So, here's a list:

States that still use centered exit tabs/justification: WA

States that have used centered exit tabs/justification but do not anymore: OR, CA, GA, CT, MO, MN (others maybe?)

With WA's center full length exit numbers, how are left exits signed? Do they just stick a yellow "LEFT" banner left of the exit number on the full length thing?

Yes, it goes inside the tab. Technically centered but it usually ends up being the full width of the sign: example 1, example 2; for signs without exit tabs, it's just stuck on top of the sign: example 3; modified signs usually have the standard exit tab with a left plaque above it: example 4.

What I don't know is whether the standard design would dictate placing the left plaque over the sign rather than inside the tab, if the sign was narrow in design.

[ran4sh]

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

Texas
New Mexico
Idaho ??? sort of

others?

New Mexico definitely qualifies - the BGS mount is a simple circle while the individual shield has the Zia sun. Idaho now uses the same blank for all applications with their recent shield redesign.

Also, add South Carolina to the list.

I'm not sure SC belongs on that list, the route marker is supposed to be the blue-on-white version with state outline and state name for both BGS and independent use, it's just that most BGS have not been replaced to have the new marker yet.

[ran4sh]

With WA's center full length exit numbers, how are left exits signed? Do they just stick a yellow "LEFT" banner left of the exit number on the full length thing?

Yes, it goes inside the tab. Technically centered but it usually ends up being the full width of the sign: example 1, example 2; for signs without exit tabs, it's just stuck on top of the sign: example 3; modified signs usually have the standard exit tab with a left plaque above it: example 4.

What I don't know is whether the standard design would dictate placing the left plaque over the sign rather than inside the tab, if the sign was narrow in design.

WA would probably have to change that eventually, considering that FHWA has advised California that their left exits need actual left exit tabs and not just an in-sign design that mimics the appearance of a tab.

[roadman65]

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

Texas
New Mexico
Idaho ??? sort of

others?

New Mexico definitely qualifies - the BGS mount is a simple circle while the individual shield has the Zia sun. Idaho now uses the same blank for all applications with their recent shield redesign.

Also, add South Carolina to the list.

I'm not sure SC belongs on that list, the route marker is supposed to be the blue-on-white version with state outline and state name for both BGS and independent use, it's just that most BGS have not been replaced to have the new marker yet.

Maryland?

[US 89]

I'm not sure SC belongs on that list, the route marker is supposed to be the blue-on-white version with state outline and state name for both BGS and independent use, it's just that most BGS have not been replaced to have the new marker yet.

Where are there blue and white SC shields on BGSs? I drove a fair amount in the Greenville-Spartanburg area yesterday and don't think I saw a single one, even on signs that looked newer.

[wanderer2575]

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

Texas
New Mexico
Idaho ??? sort of

others?

New Mexico definitely qualifies - the BGS mount is a simple circle while the individual shield has the Zia sun. Idaho now uses the same blank for all applications with their recent shield redesign.

Also, add South Carolina to the list.

Michigan does not include the block "M" on BGS shields.  You decide whether that is "substantially" different.

[Mapmikey]

I'm not sure SC belongs on that list, the route marker is supposed to be the blue-on-white version with state outline and state name for both BGS and independent use, it's just that most BGS have not been replaced to have the new marker yet.

Where are there blue and white SC shields on BGSs? I drove a fair amount in the Greenville-Spartanburg area yesterday and don't think I saw a single one, even on signs that looked newer.

This set of BGSs has been up 10 years now with new SC shields - https://goo.gl/maps/FTXuLsWdi9rs646T9

Somewhere upthread SC was mentioned as a state that always uses 3-digit shields for state routes.  Ignoring that there are still old style markers around, here are some square versions of the new shield I am aware of:

https://goo.gl/maps/L8UZrADKzM5E4gZB9

All the shields approaching/leaving this traffic circle are squares - https://goo.gl/maps/NGBKGhMF3Bg72XHj8

[Flint1979]

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?

Well you have this thread from awhile back that pretty much asks the same question.

https://www.aaroads.com/forum/index.php?topic=14484.0

[jakeroot]

With WA's center full length exit numbers, how are left exits signed? Do they just stick a yellow "LEFT" banner left of the exit number on the full length thing?

Yes, it goes inside the tab. Technically centered but it usually ends up being the full width of the sign: example 1, example 2; for signs without exit tabs, it's just stuck on top of the sign: example 3; modified signs usually have the standard exit tab with a left plaque above it: example 4.

What I don't know is whether the standard design would dictate placing the left plaque over the sign rather than inside the tab, if the sign was narrow in design.

WA would probably have to change that eventually, considering that FHWA has advised California that their left exits need actual left exit tabs and not just an in-sign design that mimics the appearance of a tab.

The FHWA doesn't seem to advise WSDOT much of anything. They still continue to use black-on-white HOV/toll signage well after the agency made it clear that they don't want that combination used anymore.

But yes, I suspect they'll move away from this practice eventually. SW WA already uses tabs in many locations (though it's still not universal); it would be easy enough for other WSDOT regions to adopt their standards if necessary.

[SkyPesos]

With WA's center full length exit numbers, how are left exits signed? Do they just stick a yellow "LEFT" banner left of the exit number on the full length thing?

Yes, it goes inside the tab. Technically centered but it usually ends up being the full width of the sign: example 1, example 2; for signs without exit tabs, it's just stuck on top of the sign: example 3; modified signs usually have the standard exit tab with a left plaque above it: example 4.

What I don't know is whether the standard design would dictate placing the left plaque over the sign rather than inside the tab, if the sign was narrow in design.

WA would probably have to change that eventually, considering that FHWA has advised California that their left exits need actual left exit tabs and not just an in-sign design that mimics the appearance of a tab.

The FHWA doesn't seem to advise WSDOT much of anything. They still continue to use black-on-white HOV/toll signage well after the agency made it clear that they don't want that combination used anymore.

But yes, I suspect they'll move away from this practice eventually. SW WA already uses tabs in many locations (though it's still not universal); it would be easy enough for other WSDOT regions to adopt their standards if necessary.

This brings up a possible potential new thread topic: regional DOT practices in a state
Like for example, even though Ohio mostly uses tabbed exits since day 1, the Columbus district had IDOT style full length exit tabs until about 5 years ago.

[briantroutman]

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

I assume by "vehicles"  you really meant "motor vehicles" ; otherwise, what other underwater tunnels are left–underwater pedestrian tunnels (like at Sea World)?

But if we stick with "vehicle" , Pennsylvania has underwater tunnels used by vehicles, both the tunnel under the Schuylkill River in Philadelphia carrying SEPTA's Market-Frankford subway line as well as multiple underground trolley lines, and the more recent tunnel under the Allegheny River used by PAT light rail to connect to Pittsburgh sports and entertainment complex on the North Shore.

That's of course in addition to numerous through-mountain tunnels for cars, trains, light rail...even boats.

[ethanhopkin14]

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.

I think Wyoming does this too.

Virginia and West Virginia also do this, but only when the exit number is 3 characters or greater.  So for every three-digit exit, or two-digit exit with a letter suffix.  I'd call that pretty widespread.

Here is my own contribution:  New York and South Carolina are the only two states that don't quite push the exit tabs on BGS's all the way to the left or the right.  They account for the rounded white border of the main sign, and have them so they aren't over the curve.  And I want to say Nebraska might do this as well, but I have only seen photos, and haven't been in that state in over 20 years.

This is why the key word "extensively was used.  I am aware many states do this, there is one in New Orleans, but these were the only two states where it was the norm, not the exception.  I know Texas doesn't use this practice anymore for new assemblies, but there are still a large amount of tabbed gore signs.  Until ten years ago, there were no numbers on gore signs in Texas.

[StogieGuy7]

Michigan and Kansas: State route abbreviations are M- and K- instead of MI and KS

You forgot Utah.  State highways are still referred to as "U-10" or "U-229" - dating back from the days when the state highway badge was literally a letter U. 

[StogieGuy7]

I'm not sure SC belongs on that list, the route marker is supposed to be the blue-on-white version with state outline and state name for both BGS and independent use, it's just that most BGS have not been replaced to have the new marker yet.

Where are there blue and white SC shields on BGSs? I drove a fair amount in the Greenville-Spartanburg area yesterday and don't think I saw a single one, even on signs that looked newer.

There are lots of them!  Including this one near Gaffney - which is between Spartanburg and the NC border.

https://www.google.com/maps/@35.1102525,-81.5986996,3a,75y,243.39h,90.6t/data=!3m6!1e1!3m4!1skBLIDNnTdsw83tdNHQWMvA!2e0!7i16384!8i8192

[TheHighwayMan3561]

Minnesota and Wisconsin: state highways are indexed as Trunk Highways (TH in Minnesota, STH/CTH in Wisconsin). Michigan calls them "trunkline highways" but abbreviates them as M-.

[kphoger]

Michigan and Kansas: State route abbreviations are M- and K- instead of MI and KS

You forgot Utah.  State highways are still referred to as "U-10" or "U-229" - dating back from the days when the state highway badge was literally a letter U. 

I got a speeding ticket years ago here in Kansas, and the officer abbreviated the location as U 400 (US-400).

[SkyPesos]

I don't know how each state exactly call its state routes, but I've seen state abbreviations (CA, IL, etc), SR for State Route, SH for State Highway, C for Colorado, K for Kansas and M for Michigan.

[kphoger]

Michigan and Kansas: State route abbreviations are M- and K- instead of MI and KS

You forgot Utah.  State highways are still referred to as "U-10" or "U-229" - dating back from the days when the state highway badge was literally a letter U. 

I have a childhood memory of seeing SR ### used on a mileage sign in Utah.  Is that not the practice there?