In Phase 2, the Silver Line continues west in the Dulles Access Road's median until it reaches the airport. Along the way, four additional stations were built with platforms in the median of the road and a faregate and pedestrian bridges to parking areas elevated above the highway. In anticipation of the station being built, in 1999 Fairfax County constructed a 1,750-space parking garage with ramps to Dulles Access Road's toll lanes and this facility is being used for bus commuters on an interim basis. The garage has drawn criticism because of alleged construction flaws. As originally planned, upon reaching the airport the track enters a tunnel which follows the path of the arrivals driveway of the airport terminal to a station located close to the terminal. The track leaves the tunnel near the airport hotel and economy parking lots and heads north parallel to the main runways. A storage yard and maintenance facility branches off to the west occupying the airport's buffer zone north of the end of its major runways. The final two stops are in the median of the Dulles Greenway, serving the Ashburn suburb. Hence, the line is expected to draw both airport traffic and commuters from the far western suburbs of Washington. D.C.. Buses currently provide these users with limited public transportation. In contrast, the Silver Line is expected to provide trains once every six minutes during rush hours and once every fourteen minutes during non-rush hours.