"If we had to make a decision today, we would not approve the project," Simpson said in a press conference yesterday afternoon.

The rail line, which would be known as the Silver Line, is a 23-mile expansion from the Vienna Metro stop on the Orange Line to Washington Dulles International Airport. The project, if built, will go through Tysons Corner and eventually into Loudoun County.

In the press conference, Simpson said the FTA is not rejecting the project design, but asking project planners to change or clarify aspects of the project's administration, funding and infrastructure to allay the FTA's concerns.

Those areas of concern range from the Metropolitan Washington Airports Authority's oversight of the project to the ability of existing Metro infrastructure to handle the proposed Silver Line's demands. It seems unlikely that they could be addressed before Jan. 31.

If final design approval is not granted by Feb. 1, the contract with Dulles Transit Partners, the entity actually building the rail line, would expire. Renegotiating that contract could cause cost escalations in the project, according to state officials.

Although Simpson characterized the decision as a chance for MWAA and the rail project to correct the problems, he was noticeably less optimistic about the project's fate in his letter to Gov. Kaine.

"The sheer number and magnitude of the current Project's technical, financial, and institutional risks and uncertainties are unprecedented. ... I have serious concerns whether it would be appropriate to continue further investment of Federal New Starts funds in this Project, except for reimbursement of FTA-approved activities," Simpson's letter reads.

According to Simpson, the project design's primary failures have to do with cost effectiveness, despite $300 million in cuts from the project this fall. According to the FTA, proper documentation showing that those cuts would actually happen was never provided.

"Because FTA has not yet received satisfactory confirmation of the proposed cost reductions, the Cost Effectiveness index value of the project would be computed without consideration of the proposed cost reductions," reads the FTA's letter to Gov. Kaine. Without the reductions, the project's cost effectiveness is rated "medium low," insufficient for FTA approval.

However, Simpson's letter goes on to list a host of problems, including the decline of Metro's infrastructure, MWAA's "limited experience with transit projects," and concerns with the plans to finance the project.

Gov. Kaine has said that MWAA and the commonwealth will respond to the letter on Jan. 28.