NC 752: Existed briefly in the 1997-99 timeframe (per various mtr posts), when a freeway stub opened from I-77 to NC 89 near Mt. Airy. When the freeway was completed to US 52, it was renumbered as part of I-74. NC 752 was essentially a placeholder as I-74 was always intended to be placed on this freeway.

NC 752 in its fleeting moment (photo by Matt Steffora)