Interstate 581 is a spur leading south from I-81 to Roanoke–Blacksburg Regional Airport (ROA) and the independent city of Roanoke. The urban freeway is cosigned with U.S. 220 as part of its route between Martinsville and Covington. I-581 is also incorporated in the Future Interstate 73 corridor through Virginia.
Exit numbers along Interstate 581 utilize cardinal direction based suffixes. Interchange numbers increase from north to south, contrary to standard Interstate numbering.
Interstate 581 opened initially from Interstate 81 south to Virginia 117 in November 1964, and south to U.S. 11A & 460 and Virginia 116 by September 1965. Completion of the route southward to Virginia 24 occurred by October 1967.1
Virginia’s second diverging diamond interchange is the Valley View Interchange along Interstate 581 & U.S. 220 at Exit 3C. The DDI replaced a partial exit built in 1999. Benefiting holiday shoppers bound for adjacent Valley View Mall, it opened to traffic following a ribbon cutting ceremony held on November 21, 2016.2 Design-build contracts for the $63.9 million project were awarded in March 2013, with road work starting in summer 2014.3