When the Metropolitan Washington Airport Authority’s board of directors meets on Wednesday, members are expected to get a briefing on construction of the Silver Line rail extension as well as a report on the latest air traffic statistics.

Rep. Frank R. Wolf (R-Va.) has been among those who’ve expressed concern about a new parkway proposed on the west side of Dulles Airport. (Alex Wong – Getty Images)

Though a staff report indicates that ‘substantial completion’ of the first phase of the rail project is expected in September, it’s possible that date may be changing. Last week, The Post’s Dana Hedgpeth reported that a top federal transportation official has raised concerns about what he says were unauthorized changes made to safety systems for Metro’s new Silver Line. Expect questions about those concerns during the board meeting.

The board’s Strategic Planning and Development Committee is also expected to be briefed on the Bi-County Parkway and other transportation projects that may affect operations at Dulles Airport. The Bi-County Parkway, which would offer a North-South connection between Prince William and Loudoun counties, has become a hot issue. While many business leaders in the two counties support the roadway, which would be located on the western side of Dulles Airport, some residents and prominent legislators, including Rep. Frank Wolf (R-Va.) and Del. Tim Hugo (R-Centreville)  have voiced concerns about whether the new road is necessary.

Supporters of the parkway say that it could help boost cargo and passenger traffic at Dulles Airport by offering easy access on the airport’s western boundary. Opponents say officials should focus on easing congestion on already existing roads before building new ones.

The Commonwealth Transportation Board is expected to take up the matter during its meeting, also scheduled for Wednesday.