Commuters are served by the Washington Metro subway and the Virginia Railway Express, a commuter railroad. Metro is the second-busiest subway system in the nation; only New York City's subway system carries more passengers. A planned expansion project will extend the system past Dulles Airport into Loudoun County. The VRE has two lines adjacent to I-66 and I-95 starting in Union Station and extending to Manassas and Spotsylvania respectively. VRE service is significantly more limited, but nevertheless saw over a year of continuous ridership increase from 2007 into 2008. Bus service is provided by WMATA's Metrobus and several local jurisdictions.