North of Blowing Rock, US 321 is already a highway of four lanes up to King Street in Boone; thus, US 321 is a four-lane highway from the South Carolina state line to downtown Boone. Currently, US 321 meets US 421 at King Street and overlaps it over King Street to leave town to the west. NCDOT project R-2615 is proposed to widen the US 321/421 concurrency from this junction to their junction near Vilas, although this project is currently unfunded. There is a feasibility study (FS-0511A) in progress to examine the possibility of widening US 321 from the junction near Vilas to the Tennessee state line. If both of these projects were completed, then US 321 would be a four-lane highway through the entire state.