IL DOT signs

[Zendavor Signs]

Anyone have experience making highway signs for the Illinois DOT? These will be business logo signs for exit ramps. Their guidelines state this for digital print signs:
"Design submittals for digitally printed signs must also include a valid certification letter from the sign sheeting manufacturer stating that the sign fabricator’s digital printer is capable of producing digitally printed signs"

Where do you start to get this information? I know I could have Grimco make these signs, but it would be great if I could make them in-house.

 

[ChicagoGraphics]

I believe there are certain machines that are classed as certifide digital printers not just any printer can print DOT signs for highways.

 

[rjssigns]

Could start here: https://mutcd.info/ Only printer I can think of right now is the TrafficJet.