Made an interesting discovery...there is a bannered ND3 Business route in Rugby. I noticed only a total of 3 signs total:
this sign going south on ND3,
this one indicating a turn of the business route onto Main Ave, and
this third one showing a turn from 3rd Ave SW onto 4th St SW. So while this one doesn't have all of its turns signed in each direction, one can figure the route from S to N goes:
ND3 to 3rd Av SW
3rd Ave SW to 4th St SW
4th St SW to Main Ave
Main Ave to 1st St NW
1st St NW to ND3
I figure this is probably enough for inclusion into the HB, but given that it's not signed that well, I'd also understand if it's not.