sentences:  SR 121 is part of a Virginia Byway that continues south along US 52 and west along SR 610 to Wytheville.SR 121 begins at a diamond interchange with I-77, I-81, and US 11 a short distance west of the interchange where I-77 turns south toward Charlotte and I-81 and US 11 continue east toward Roanoke.US 52 runs concurrently with the three other highways west to Wytheville and heads south from the interchange as Fort Chiswell Road toward Hillsville.