Phase 2 of the Silver Line project will go through Dulles International Airport to a new terminal in Loudoun County. (Dulles Metrorail Project map)

The next phase of the Silver Line construction project is about to leap over the Centreville Road Bridge on the south side of Herndon in a two-month construction program set to begin next week.

The Silver Line route will head west along the Dulles Toll Road/Access Highway from the phase one terminus at Wiehle Avenue toward Dulles International Airport. The Centreville Road Bridge is in between. Construction crews will build a rail bridge over the traffic bridge.

[See full coverage of the Silver Line project]

Planners say the key parts of this project will take place over 15 to 20 nights in October and November. The big impact on late night/early morning drivers: Centreville Road will go down to one lane each way from 9 p.m. to 5 a.m. Also planned are intermittent full closings of Centreville Road between midnight and 5 a.m. on the construction nights. The full closings will vary in length from five to 20 minutes each.

Most of the construction will be in the median of the Dulles Access Highway, but two large cranes will be set up on the highway and will require closing the left lanes on both sides. A third crane will be placed within the closed part of Centreville Road.

The work is scheduled to start Monday night, but the exact timetable for placing the girders, beams and deck plates will depend on the weather.

The map shows the work schedule at the Centreville Road Bridge over the Dulles Toll Road/Access Highway. (Dulles Metrorail Project map)