Serving the North Carolina cities of Greensboro, High Point and Winston-Salem, Piedmont Triad International Airport (GSO) is the state's third-busiest airport, handling more than 900,000 passengers in 2013. Allegiant Air, American Eagle, Delta Air Lines, Frontier Airlines, and United Express fly between GSO and more than a dozen US destinations. The airport consists of three runways and a passenger terminal with two concourses – the North Concourse and South Concourse – and 30 gates. Garage parking, short-term parking, long-term parking and valet parking are located across from the passenger terminal. Ground transportation options include a Piedmont Authority for Regional Transportation (PART) shuttle to the PART Regional Hub, as well as taxicabs, shared-ride vans, hotel shuttles and rental cars.