Wonders what does the fed. have to do with state, county or local roads and why they are regulating something as low priority, wonders how much it cost us to figure out.
If the FED pays for the sign or is on a FED maintained highway, they have a say as to how it is designed and the guidelines are free to get and read. Signs paid for by the FED or on roads maintained by them need prior review before the sign goes up.
To most municipalities, this is bonehead regulatory sign knowledge, they really should know this. There are some portions of the code that are very wordy and hard to get, but this is a sign that they should have know was required to be upper/lower case.
This regulation was done way before the mentioned person you are blaming this for. The regulation is in place to make sure the money that is spent is done with some level of standard that works from one end of the country to the other, they are allowed to add some design elements... by the way usually cities are the ones who will take FED highway funds as well as state and their own and produce massive city wayfinding projects. Some look great, but local municipalities are more to blame than the maintaining of a federal standard.