Rest area mile marker signs, and other signs exclusively at rest areas

[D-Dey65]

What is the MUTCD code for Rest Area Mile Marker signs?
https://commons.wikimedia.org/wiki/File:SB_I-75_Rest_Area,_Alachua_Co,_FLA-22.jpg
https://commons.wikimedia.org/wiki/File:S3010231_(3844518905).jpg
Because I haven't been able to find any information on them.

[vdeane]

What is the MUTCD code for Rest Area Mile Marker signs?
https://commons.wikimedia.org/wiki/File:SB_I-75_Rest_Area,_Alachua_Co,_FLA-22.jpg
https://commons.wikimedia.org/wiki/File:S3010231_(3844518905).jpg
Because I haven't been able to find any information on them.

There might not be one.  Signage is a little more flexible once you're off the highway.  Just look at NY moving all the Cuomo Signs that it couldn't fold into the "experimental tourist sign pilot program" to the rest areas.

[Bitmapped]

West Virginia uses an all-text sign like this: https://maps.app.goo.gl/jS6Qk6spdp7fLqVf8

Ohio's ODOT has two rest area identification signs, which are often posted near the entrance. Both show the rest area identifier. The D5-H29 shows the location of the rest area in miles since the county line, but that's not really obvious to the general public.
D5-H29: https://www.dot.state.oh.us/roadway/sdmm/SDMMSignFiles/D5-H29.pdf
D5-H30: https://www.dot.state.oh.us/roadway/sdmm/SDMMSignFiles/D5-H30.pdf

[roadfro]

What is the MUTCD code for Rest Area Mile Marker signs?
https://commons.wikimedia.org/wiki/File:SB_I-75_Rest_Area,_Alachua_Co,_FLA-22.jpg
https://commons.wikimedia.org/wiki/File:S3010231_(3844518905).jpg
Because I haven't been able to find any information on them.

There is no national MUTCD sign code for this. This is not a standard sign application.

[ElishaGOtis]

While not technically in use anymore, the 2003 MUTCD RA-040 sign for an elevator could have had use at a few locations, such as at a few service plazas on the NYS thruway or that one rest area on I-90 in SD.