Don, I didn't do a mile plot, but these might be added to your list (as amended by Nancy) without undue hardship. It just would take a little more looping:
MD 34 southwest of Boonsboro
MD 67 south of Boonsboro
WV 9 12 31 and 34 in the Shepherdstown area
WV 8 11 18 and 19 in the Martinsburg area
WV 24 26 and 51 in the Inwood area
WV 2 and 13 around Summit Point
That takes you from your original 14 to 31. Hell, you could win this thing in one day.
As you know, no good deed goes unpunished, so in return I want you to check out what's supposed to be U.S. 48 running from Strasburg VA to Weston WV. It is claimed that this highway, which had either never been commissioned or not had been commissioned for years, rose from the ashes in 2002. I'll believe it when I see it.