Metro will begin replacing the entrance escalators at one of its busiest stations Monday.
The Bethesda Metro station on the Red Line has the second-longest escalators in the system, but the station's three escalators are also more than 30 years old.
Crews will keep two escalators running -- one in each direction -- while the third is replaced. The project is expected to take two and half years to complete. To keep riders safe, the work will be done overnight when the station is closed.
Metro says it may have to close the station temporarily at times to help prevent overcrowding. These closures may happen with little advance notice.
During those closures, shuttle bus service will run between the Bethesda station and the Medical Center Metro station.
Metro has more escalators than any transit system in North America, more than 600 of them.