States that have signs that tell the name of the road on an freeway overpass.

[Darkchylde]

From what I've seen so far in Missouri, they do post the names, for both overpasses and underpasses, but only if the roads do not intersect nor interchange. Mind you, what I've mostly seen has been in and around Kansas City. They might not do it in the really rural sections; I just don't know.

[Scott5114]

Kansas does this consistently for bridges crossing over the freeway. Not for roads crossing under it.

There is one instance in which this is done in Oklahoma City–the interchange between Northwest Expressway (old OK-3A) and May Avenue has such a sign on the May Avenue bridge; it reads "MAY AVE" in all uppercase button copy, and may in fact be a black sign!

I would like to see a photo of this.

as of 2006, there was one black button copy sign I know of in Oklahoma City - it listed some kind of regulations on the Kilpatrick Turnpike.  I can't remember if it was speed, weight, height, or something similar.

You're in luck! Google Maps seems to have sent a high-res street view car through there. https://maps.google.com/maps?q=may+avenue+and+northwest+expy+oklahoma+city&hl=en&ll=35.526306,-97.565342&spn=0.007125,0.013218&sll=35.309049,-98.716558&sspn=7.313306,13.535156&hnear=N+May+Ave+%26+Northwest+Expy,+Oklahoma+City,+Oklahoma,+73112&t=m&z=17&layer=c&cbll=35.526336,-97.565465&panoid=a7DrVURy-1Vf6GZqu7lTvA&cbp=12,249.17,,0,-6.57

[national highway 1]

NSW does this extensively with both overpasses and underpasses, with black all-caps text on a white background.

[kkt]

Alabama does. I know I've seen them on I-10. I don't remember about the rest of the state.

Texas does in urban areas

Alabama does have the signs throughout the state on its interstates. They were installed in 2007-2008. Sometimes the route shield is displayed if the name of the road is shown. Otherwise, it is AL xx, US xx, or CR {county name} xx. The signs also show the milepost of the overpass. Here is an example of one of the signs.

Georgia also does it. They even have the name of the railroad when it is a railroad overpass (e.g. CSX).

Here is a better example of what Alabama does.

I like that.

[Zeffy]

  Plus I would figure that with NJDOT replacing the guide signs over the past two decades on Route 495, they might of got rid of them for the same signs  they useon the NJDOT freeways that are attached to the overpass itself that were added in both the 90s and 00s.

Are you talking about signs like this one on Federal City Rd on I-95 SB?

[mjb2002]

Also, NYC used to have them, I think (its very vague memory), on blade street signs attached to the light poles in the median of some NYC expressways at overpasses as well.

FDOT stamps street names into bridges with black paint filling in the indents, but can only be read in stopped traffic of course.

SC, I have seen, coded numbers on some of the I-95 overpasses instead of road names or route numbers.  I am guessing that these might be like NYSDOT with reference numbers to the roads itself.

South Carolina just had the highway number of the primary highway (state, federal or Interstate) or secondary road listed on the bases of the overpasses.

I saw this on Interstates 26, 77 and 95.

I do not know if SCDOT do this anymore.

[roadman65]

I forgot but NJDOT was experimenting with them on NJ 27 back in the 80's and were using for all bridges over and under with a decimal number representing its location on its mile posts.  I believe that you may find some signs left over in places.

[ftballfan]

Michigan has this and is consistent at it.

[midwesternroadguy]

I recall them in Wisconsin 

They have general ones in most of Wisconsin, but in Milwaukee County, they add what block address the street represents (such as 8800 North) for non-numbered streets.

Wisconsin used to sign all County Trunk Highways, State and US Highways and all township roads at over- and underpasses not in interchanges.  However, in the 1980s, WisDOT removed most of the signage for township roads in rural areas at bridges.  Signage for local streets remains at many urban area bridges.

[hotdogPi]

Massachusetts does it too. Sometimes, but not always, there will be an accurate mile marker on the side of the tunnel (normal mile markers are sometimes inaccurate).