U.S. Route 70 traverses approximately 488 miles (785 km) across North Carolina; from the Tennessee state line, near Hot Springs, to the community of Atlantic, along the Pamlico Sound coastline.

U.S. 70 enters North Carolina on a two-lane road, also signed as U.S. Route 25. The duplex is signed along a divided highway from Marshall to U.S. Route 19 north of Asheville where it splits off from U.S. 25. From here, U.S. 70 parallels Interstate 40. From the town of Ridgecrest at the top of the Blue Ridge, U.S. 70 merges with I-40. It splits from I-40 again at the bottom of the grade at Old Fort, then passing through the towns of Marion, Nebo, Morganton, Hickory, Conover, Statesville and Salisbury, where it changes course and heads northeast.

U.S. 70 parallels Interstate 85 to High Point, sharing a divided highway with U.S. Route 29. The two roads separate in Greensboro, and U.S. Route 70 joins Wendover Avenue out of the city and continues east along the Interstate 40 corridor. Halfway to the Research Triangle, US 70 passes through the major retail district for Burlington. It then becomes a two lane road until it reaches Durham where U.S 70 turns southeast as a divided highway. The road passes straight through downtown Raleigh, before heading back east and away from Interstate 40.

A divided highway from Raleigh to the Atlantic Coastal Plain, U.S. 70 traverses Eastern North Carolina in an east by southeasterly direction. As of 2008, the Clayton Bypass carries US 70 around Clayton, North Carolina. It is signed along as bypass roads around Smithfield (through Selma) and Goldsboro and a freeway around New Bern and is a divided highway again through the Croatan National Forest and Havelock, passing Atlantic Beach in Carteret County, the eastern terminus of NC 24. From here, U.S. 70 maintains a two-lane road with a widened shoulder, to the town of Sealevel and the southern terminus of NC 12. The last few miles of U.S. 70 are signed along a road from Sealevel to its eastern terminus in the town of Atlantic.

The Clayton Bypass is a four-lane highway opened on June 9, 2008, in Johnston County, North Carolina, United States, that carries mainline U.S. Route 70 around the city of Clayton, North Carolina. It connects Interstate 40 near the southeastern corner of Wake County to US 70 just northwest of Smithfield. It is intended to reduce congestion on US 70 in the vicinity of Clayton, cutting an estimated 15 minutes of travel time for drivers traveling between Raleigh and the eastern part of the state, but concerns have been expressed that it will increase congestion on a heavily traveled stretch of Interstate 40 in southeastern Wake County.

The bypass was first planned in 1991, but several setbacks, including controversy over building a bridge through territory of an endangered mussel, held up beginning the project until 2005. Originally scheduled for completion in June 2009, a severe drought in the area through most of 2007 and into the spring of 2008 allowed construction to proceed more rapidly than anticipated, and the highway was opened June 9, 2008.

The western end of the bypass connects to Interstate 40 approximately four miles southeast of the current I-40-US 70 interchange. The eastern end connects to the US 70 bypass and business routes northwest of Smithfield, North Carolina. The combination results in an effectively continuous business route passing through Clayton and Smithfield and an effectively continuous bypass passing south of Clayton and north of Smithfield (and east of the community of Cleveland). Drivers are thus able to bypass Clayton, Smithfield, or both.

The Clayton Bypass is a limited access freeway of two lanes in each direction, with interchanges at Interstate 40, North Carolina Highway 42, Ranch Road, and US 70 between Clayton and Smithfield, North Carolina. To complete the bypass and connect with U.S. 70 business, the US 70 bypass actually overlaps with I-40 for four miles (6 km) in southeastern Wake County southeast of Garner.

Electronic signs provide traffic information and estimates of travel time, a first in the area, and cameras and pavement sensors provide traffic engineers real-time information about the number of vehicles and their speeds.

A multi-county project called the "Super 70 Corridor" is currently in various stages of construction and planning in the following counties: Wake, Johnston, Wayne, Lenoir, Jones, Craven, and Carteret. Goal is to make US 70 from Raleigh to Morehead City into a limited-access freeway. The project also organizes all various projects in an order that is agreed to the counties involved.

Projects currently involved: