North Carolina normally does not allow two highways in the state to have the same numbers. Back when US highway numbers were introduced, state highways with the same number were renumbered. In the 1990's, two new Interstate highways numbers were introduced, I 73 and I 74. North Carolina already had a state highway, NC 73, and a US highway, US 74. This duplication should be fixed.
NC 73 is a midlength state highway which actually crosses the corridor for I 73, which is currently under construction. When the freeway is opened, there will be an exit on I 73/74 for NC 73. NC 73 should simply be renumbered to NC 173.
US 74 is actually multiplexed with I 74 Future from Rockingham NC to Whiteville NC.
Renumbering US 74 is a more complicated issue. This involves petitioning the AASHTO and involves another state, Tennessee. However, US 74 is largely multiplexed with other US highways already. US 74 should be retired entirely and multiplexed sections of the route be simply demultiplexed.
US 74 Alternate - Asheville NC to Forest City NC - Renumber to NC 374.