A study of potential Metro expansions currently has no timetable.
Two Virginia congressmen are studying the possibility of extending the Metro transit system to Centreville in western Fairfax County and Woodbridge in Prince William County.
Democratic Reps. Gerry Connolly and Jim Moran say population growth in both counties and the expansion of Fort Belvoir will make additional transit options essential for the region, according to the Associated Press.
There's no timetable for completing the study, and it's not clear how much an expansion would cost. The project would use existing rights-of-way.
The original Metro plan from the 1960s called for extending the rail network as far south as Prince William.
Metro is in the midst of a major expansion to Dulles International Airport. The first phase of that project will open later this year.