The road becomes a freeway at C. Grier Beam Boulevard in Gastonia, just south of NC 275/NC 279. It remains a freeway until just north of its junction with US 70 in Hickory. The freeway bypasses a number of cities that the old US 321 route once passed through. Today, US 321 Business follows the original route, which serves Maiden, Newton, and Conover, but the freeway is a more direct route to the mountains, and the business route is generally used by local traffic only.