The $2.8 billion extension of the D.C. region's Metrorail system known as the Silver Line is now about two months behind schedule.
The Metropolitan Washington Airports Authority, which is overseeing Silver Line construction, said Wednesday that needed safety and performance tests have extended the project's timeline by about eight weeks. Officials had initially estimated the line would be open to riders by the end of the year.
The Silver Line runs through Tysons Corner to Reston. Work recently began on a second phase extension of the line to Dulles Airport and Loudoun County. That phase won't be complete until 2018.