The inspector general for the U.S. Department of Transportation announced Tuesday that his office will audit the authority that oversees two of the Washington area’s main airports and the project to extend Metrorail to Dulles International to Loudoun County.

Inspector General Calvin L. Scovel’s announcement that he will investigate the “management policies and processes” of the Metropolitan Washington Airports Authority comes in response to a request in February from Reps.Frank R. Wolf (R-Va.) and Tom Latham (R-Iowa). The lawmakers requested the audit, they said, to “ensure that Dulles Rail is done well, done on time, and done on or under original cost estimates.”

The airports authority, which took charge of the planned 23-mile Metrorail line in 2006, has been criticized for the rising cost of the second phase of the project. The inspector general’s office is currently completing an audit of the first phase of the project from Tysons Corner to Wiehle Avenue in Reston. The new review appears broader in scope, covering the second phase to Dulles and Loudoun County, in addition to looking at the airports authority and its 13-member appointed board.

In its announcement, the inspector general’s office says it will examine whether that the authority’s “policies and processes are sufficient to ensure accountability and transparency of its board’s activities.” The announcement also mentions that “recent decisions by the MWAA Board regarding the project have generated significant attention.”

The unelected board has been hammered by local, state and federal officials for its management of the second phase of the Metrorail project and its vote in favor of building an underground Metro station at Dulles. Elected officials representing Northern Virginia prefer a less expensive aboveground station. U.S. Transportation Secretary Ray LaHood is mediating ongoing discussions between the board and regional officials designed to trim the cost of the project and reach consensus on the airport station.