The bridge being built over the Beltway in Tysons Corner as part of the Dulles rail project. (Jahi Chikwendiu/WASHINGTON POST)

Multiple lane closures are scheduled on the inner loop at Route 123 this week as part of the effort to extend Metrorail to Dulles International Airport and Loudoun County.

Crews plan to close three right lanes of northbound I-495 beginning Tuesday from 11 p.m. to 5 a.m. Closures, which are due to the construction of an overhead bridge that will carry Metro trains, are also scheduled for Wednesday, Thursday and Friday.

The closure of two right lanes on southbound 495 at Route 123 is scheduled for Sunday from 10 p.m. to 5 a.m.

Project officials warn that drivers should expect delays in the area during the closures.

All ramps to route 123 will be open, and police will be on site, officials said.