An unfinished staircase and escalator pad at the Wiehle Avenue station on Metro's new Silver Line on Sept. 28, 2011.

The problem of broken escalators is a perennial complaint among Metro riders. We are used to seeing workmen deep into the pits trying to get the balky machines running again, or, as Metro customers, we walk brisking up moving staircases that never seem to actually move. What we rarely see are pristine units free of their normal housing.

(Photographs by Michael D. Bolden/The Washington Post)

Metro plans to spend $150 million over the next five to six years to replace and rehab about 144 escalators and 31 elevators, but there will be few new escalators installed. Stations getting new units include Bethesda, Dupont Circle, Foggy Bottom and Pentagon, but the program is focusing on escalator renewal because Metro says it can’t afford widespread replacements when new ones cost about $2 million each, depending on their length.

Two escalators await installation at the Wiehle Avenue station.