McLEAN, Va. (AP) -- The commuter rail line linking Tysons Corner and Reston to the extensive D.C.-area subway system cost nearly $3 billion.
By 2018, the Silver Line will extend west another 11 miles to Dulles International Airport at an additional cost of $2.7 billion.
As opening day approaches, questions remain about whether the project was worth the cost.
It is one in a series of large-scale construction projects aimed at easing congestion in a region known for traffic jams.
In the last decade, the region has untangled the Springfield Mixing Bowl, built a new Woodrow Wilson Bridge over the Potomac River, and added Express Lanes to the Capital Beltway.