(EDITOR’S NOTE: This story has been updated with the correct information on the number and duration of the station closures.)

A pair of Northern Virginia Metro stations on the Blue Line will be closed on weekends until March while the mass transit agency repairs a control system that’s more than 40 years old.

The Franconia-Springfield and Van Dorn Street stations will close Friday through Sunday this weekend. After that’s they’ll close Saturdays and Sundays through March 14, the City of Alexandria said. They’ll also be closed the weeks of Christmas and New Year’s — Dec. 20 through Jan. 2.

The closures won’t be in effect during the week of the presidential inauguration (Jan. 16-24) and Presidents Day weekend (Feb. 13-15).

The work will help modernize the Alexandria Rail Yard’s signal system.

During the closures, the city said, local and express shuttle buses will replace train service. Blue Line trains will operate between Huntington and Largo Town Center.

The city said the work could not be done safely while trains remain in service.

“Working with local jurisdictions, Metro decided on the series of shutdowns because completing the same work with weekend single tracking could more than double the time for completion, while providing severely limited rail service with waits up to 36 minutes between trains,” the city said in a news release.