Which states still mount the overhead signs on the bridge?

[SeriesE]

I'm not really sure why it would be a problem to mount signage on a bridge structure?  California does mount signage sometimes where it really isn't appropriate like the off center overhead gantry on I-5 northbound approaching CA 99 near Wheeler Ridge.  The sign is mounted onto the bridge carrying Wheeler Ridge Road is somewhat well known for being off angle:

https://flic.kr/p/2fHciww

Because it causes problems for the bridge itself, such as the drilled holes for sign mounting hardware resulting in the structure being compromised or for allowing a location that becomes easily susceptible to corrosion and other weather effects, also, tall signs can affect how the bridge handles strong winds, etc.

It's weird that CA mounts it at an angle like that, there are states that I've seen where they will include some kind of additional bracketing/hardware when the bridge is at an angle so that the sign will be at the correct angle, for example https://goo.gl/maps/miEbQKjdpUHUPMBg7 . This is in Georgia but I think Georgia is one of the states that no longer mounts signs to bridges.

It really depends on the agency. The San Francisco Bay Area's district does adjust the mounting location to so the sign is at the correct angle: https://www.google.com/maps/@37.4038183,-121.9066151,3a,75y,254.65h,78.06t/data=!3m6!1e1!3m4!1ss9e1kipf650NpkgUhA2r7w!2e0!7i16384!8i8192

[SeriesE]

This setup on I-77 in Columbia always bothers me. The bridge is at such a sharp angle, yet this is the only spot around with bridge mounted signs. classic south carolina.

That's straight from the Caltrans playbook!

Very Wheeler Ridge:

https://flic.kr/p/QFhTXL

^^^

Note the bridge date stamp on the left, that tells you all you need to know about Caltrans stance on mounting signs to bridges.

Might be a whoosh moment here: the date stamp says 2010 but it appears that was painted over the old date stamps?

The bridge style looks too old to be built in 2010 too.

[Big John]

^^ The contractor sometimes put in the year of rehabilitation.

[fwydriver405]

New Hampshire definitely still mounts signs on bridges. A very high example here: https://goo.gl/maps/t8jrtLbkRJb2LkPZ7

NHDOT does still mounts BGSs on bridges, albeit rarely these days, as they have been either preferring gantries or ground mounted signs. Here's a more recent one at Exit 4 Southbound (2020-08-23):


In Maine, the Maine Turnpike Authority does still mount BGSs on bridges, like this one on Exit 44 and this ½ Mile one for Exit 45, but as far as MaineDOT, I think they prefer ground mounts or gantries. Exit 22 (Southbound old, new), (Northbound old, new) on I-295 are prime examples of such conversions.

[tolbs17]

These also count. No longer practiced in North Carolina, Virginia, and more states I'm sure.

https://goo.gl/maps/uKcUgME9ZE4wjqa56

https://goo.gl/maps/AVkfCoWZe7vosQm88

https://goo.gl/maps/8vHZkmTm7ZAnVAUf8 (And as you can tell, more signs were attached to this bridge). Here are the faded spots: https://goo.gl/maps/UE9iRfEZ3pbn4hUj6

[tolbs17]

I'm guessing they put those razor blades around the sign to prevent vandalism to it. Like it getting graffiti.

Christopher Columbus Transcontinental Hwy
https://maps.app.goo.gl/irqQy8xEmH4mqybr9

[TheHighwayMan3561]

Christopher Columbus Transcontinental Hwy
https://maps.app.goo.gl/irqQy8xEmH4mqybr9

This freeway has a number that's much more well known than the name you apparently thought is the primary designation of the road...

[Max Rockatansky]

Christopher Columbus Transcontinental Hwy
https://maps.app.goo.gl/irqQy8xEmH4mqybr9

This freeway has a number that's much more well known than the name you apparently thought is the primary designation of the road...

I think there was a thread once in Pacific Southwest where we talked about this being the only freeway name in California not being signed anywhere. 

[ClassicHasClass]

I may have been imagining this, but I really do remember a Columbus sign just past the McClure Tunnel back in the day.