Sections follow the segment numbers on NCDOT's March 2026 design maps for the I-77 South Express Lanes. The NCDOT layer is their preliminary design (10–15% complete, subject to change), lined up on the ground by hand to within a few metres.

The blue line is today's I-77 (© OpenStreetMap contributors). It is not the footprint of the new lanes.

Historic maps: U.S. Geological Survey topographic maps, 1905–1993, and the 1953 Sanborn fire-insurance maps (georeferenced by volunteers at OldInsuranceMaps.net). The 1905 map is placed to within about 50 m; its own survey is no more precise than that. Aerial photos: NC OneMap orthoimagery, 1993 and 2005, and USGS National Map imagery for today. All public domain.

Hatched grey means no map of that year covers that ground. The USGS never re-issued the uptown sheet after 1967, and the Sanborn maps cover the built-up city only.