The Silver Line is being built in two phases. Monday night’s work is at the Wiehle-Reston East station, end of the first phase. (Gene Thorp/The Washington Post)

Westbound traffic will encounter overnight delays on the Dulles Airport Access Highway and the Dulles Toll Road near Wiehle Avenue in Reston where the Metrorail construction project is placing a pedestrian bridge.

This is one of several nights of work to set up the bridges that eventually will allow Silver Line riders to reach the Wiehle-Reston East Metro station. Much of the activity on the project this fall involves construction of the new stations and the access points.

The Monday night work will affect traffic from 9 p.m. to 5 a.m. This is the schedule:

From 9 to 11 p.m., the westbound airport access highway will be completely shut. The westbound toll road may close for 10-minute stretches. All westbound traffic on the access highway will be detoured onto the westbound toll road via the bus ramp near mile marker 8.6, just west of the Beulah Road bridge.

All westbound traffic on the toll road will merge into the far right lane before Wiehle Avenue, then exit at Wiehle Avenue, cross over and reenter the toll road by Wiehle Avenue’s westbound entrance ramp. Airport-bound drivers will be able to get back onto the access highway at the ramp just beyond the Monroe Street overpass, near mile marker 3.4.

 From 11 p.m. to 3 a.m., the airport access lanes will reopen, but the detour for the toll road drivers will continue. Then from 3 to 5 a.m., the first phase will repeat, with the full closing of the westbound access highway and the 10-minute closings on the toll road.