The improvements to the I-40/I-77 interchange were divided into two sections by the N.C. Department of Transportation.
Construction of the first section is complete. It involved widening I-40 to three lanes in each direction from Old Mocksville Road to east of N.C. 115, building a diverging diamond interchange at I-40/U.S.21, and reconstructing U.S. 21 from south of I-40 at BB&T Bank to north of Glenway Drive.
Other improvements included:
- Building an I-40 westbound collector-distributor road, which serves to move traffic from local streets to high-capacity roads.
- Replacing the bridge on Radio Road over I-40.
- Building a bridge on I-40 over U.S. 21 and Fourth Creek.
- Building a bridge from Sunset Hill Road to Gaither Road to connect U.S. 21 and Gaither Road, eliminating the two-way ramp at U.S.21/I-40.
- Building a ramp from westbound I-40 to northbound I-77.
- Building a ramp from northbound I-77 to eastbound I-40.
- Building parallel lanes on I-40 West that allows vehicles to access U.S. 21, as well as accessing I-40 from U.S. 21 without disrupting the flow of traffic.
- Building a ramp fly-under, which is the collector-distributor road, to U.S. 21 (I-77 north to U.S. 21 and I-40 westbound, I-77 South to U.S. 21 & I-40 westbound and I-40 westbound to U.S. 21).
- Closing I-40 Exit 153 (U.S. 64).
- Upgrading I-40 Exit 154 (Old Mocksville Road) into a diamond interchange.
- Building noise walls along I-40.
Construction is underway for the second section, which includes:
- Constructing a partial turbine interchange at I-40 and I-77.
- Widening I-40 from Radio Road to Old Mocksville Road.
- Building collector-distributor lanes on I-40 East for I-77.
- Widening I-77 from Jane Sowers Road to Salisbury Road.
- Widening East Broad Street from Vine Street to Signal Hill Drive (as part of a separate project, STIP U-6039).
- Replacing bridges on U.S. 64 (Davie Avenue) and Broad Street.
- Replacing bridges on I-77 over Fourth Creek and I-40.
- Widening bridges on I-40 over the U.S. 21 collector-distributor loop.
- Building new bridges on I-40 over an unnamed creek just east of the interchange.
- Removing existing bridges on I-40 over closed ramp from U.S. 64.