I have no idea why a 22-mile Interstate would just be given a 2di designation. Sure, it has a nearby military base, which is really the Naval Academy in Annapolis. Shouldn't this be just renamed to a 3di? Perhaps Interstate 183 or something?
Eh. I don't know what to say.
Interstate 97 --- Do you think that this freeway should be renumbered? (https://www.aaroads.com/forum/index.php?topic=1319.0)