As the soon-to-open Silver Line sets its sights west to Dulles Airport and Loudoun County, documents show that Dulles Toll Road users are paying an increasing portion of the rail project's costs.
Tolls were projected in 2004 to cover about 25 percent of the Silver Line's construction costs, according to an agreement between the state and the contractors.
But toll road users are covering nearly twice that, according to an analysis by The Washington Post.
The amount covered by tolls isn't capped and could go higher. A $2 billion federal loan agreement that was recently approved is intended to spare drivers from paying more.
Watchdog groups and several local elected officials are lobbying to stop additional toll increases as a revenue source for escalating construction costs of the line.
The Silver Line is the nation's largest and most expensive public works project at an estimated cost of just under $6 billion.
The first phase of the Silver Line – seven months late and $150 million over budget – is scheduled to open July 26. It extends Metro 11.5 miles from West Falls Church to Tysons Corner to its terminus at Wiehle Station in Reston.
The first phase has cost $2.9 billion, with bills still coming in.
The second phase of the Silver Line, an 11.7 mile extension to the airport and stations at Route 606 and Route 772 in Loudoun County, is projected for completion in 2018
Construction on the second phase is expected to start soon at an estimated cost of $2.7 billion.
Delays, cost overruns and public response to increasing tolls have raised anew questions about financing the project and the impact on taxpayers and toll road users.
Since construction began five years ago there have been five toll increases, raising a typical round trip for commuters from $2.50 to $7. At a monthly cost for weekday commuters, the typical cost has risen from $50 to $140 a month.
The rising tolls have caused some motorists to suspend or reduce their use of the toll road and seek alternative routes on non-toll highways.
Still, tolls remain the primary source of funding for the Silver Line.
The Metropolitan Washington Airports Authority, which oversees construction, moved to mitigate the burden on commuters and tolls with the $2 billion federal loan package that was approved in April. MMWA said the loan would enable it to freeze tolls until 2018.
Toll road users would have borne a higher share of the Silver Line's costs – 52 percent, according to The Post – if the loan had been approved.
Loudoun County supervisors agreed to the county's share of the loan in May. Under a 2007 funding agreement, Loudoun and Fairfax counties and the airports authority committed to covering 25 percent of the project's total costs. The federal government committed $900 million to the first phase.
One Loudoun legislator, Del. David LaRock (R-33), has led a campaign to stem the reliance on tolls to finance construction costs. LaRock maintains the Silver Line has been put on the backs of toll road users. He supported the low-interest federal loan and is working to freeze further toll road rate increases