The initial phase of construction is designated Interstate 540, and was completed in January 2007. It runs from Interstate 40 near the RDU Airport to I-87/US 64/US 264 south of Knightdale. The original plan was for the entire route to be designated as part of the Interstate Highway System, possibly renumbering the route to I-640 when the beltway was complete. When it became financially unfeasible to construct the entire route with public funds, it was decided that the remaining portion of the route (approximately 2/3 of the total completed mileage) would be constructed as a toll road and designated as a NC State Route rather than an Interstate Route. The first section of NC 540 was opened in July 2007 extending westward from the western terminus of I-540. Further extensions have carried NC 540 around the western side of Wake County to its current southwestern terminus south of Apex. Future projects are planned to complete the southern leg from Apex to Garner and eastern leg, from Garner to Knightdale, under the same toll system. In particular, the portion south of Garner has been held up due to conflicting interests in choosing a path for the route. No clear timetable exists for completion of the two legs.