Without requiring the hotly debated tunnel to be built at Tysons Corner, last month Fairfax County, Virginia, approved agreements to help fund the first phase of Dulles metrorail extension outside Washington DC.

The move enabled the project’s sponsors to seek Federal Transit Administration (FTA) clearance to move to the final design stage, hoped to begin in August/ September. With the remaining approvals, major construction could begin in the first quarter of 2008 for completion in 2013.

In a separate move, a blow was struck to the hopes of the tunnel option in late May when a petition made by Tysons Tunnel Inc to have the environmental review re-opened was denied by FTA. The application was rejected as FTA said the lobby group had sufficient opportunity to put its Case in the public consultations for the project.

Last month, a majority vote in Fairfax County’s board of supervisors’ regular meeting ok’d local funding and cooperative agreements with the scheme sponsors, which is a requirement of FTA’s approvals process.

The meeting also voted to raise funds from a tax district towards the development of the first phase of the project, which is a key step in the sponsors’ later applying for a full federal grant. Fairfax’s share of the first phase costs is 16.1%, or US$400M. The county has already collected close to US$50M.

Conditions placed on the approvals by the board, include: the scope of the scheme is not changed, without its approval, from that agreed earlier last month between the sponsors – Metropolitan Washington Airports Authority (MWAA) and Dulles Transit Partners – a JV between Bechtel and Washington Group; the scheme receives a satisfactory risk assessment rating from FTA; the total cost of the scheme does not exceed US$2.647bn.

However, the county did not specify that a view on whether a tunnel should be built at Tysons Corner as part of its assessment and approvals, which enabled it to ensure the project remains alive and can seek federal funds.

The board’s approvals paves the way for the scheme to enter final design and also helps maintain the viability of the US$1.6bn bid offer by Dulles Transit Partners, which was approved by the Commonwealth of Virginia earlier this year. Early design assessments rejected a tunnel option at Tysons Corner but lobbying continues.

The 40km extension to the metrorail will take the line into Tysons Corner and the Dulles Corridor to Reston, Herndon, Dulles International Airport, and Loudoun County. The first phase of the project has completed its Environmental Impact Statement (EIS) and a record of Decision from the FTA and the Federal Aviation Administration (FAA). The project scope has eight stations in Fairfax County. The second phase is estimated to cost US$2.5bn, taking the line farther into Loudon County.