WASHINGTON – Metro’s interim general manager has asked an outside company to examine how well Metro maintains its escalators and elevators. That study began in May and a preliminary report is expected in September.

Managers at the transit system say they are striving for at least 93 percent reliability for escalators. As of midday Wednesday, that figure was only 88 percent.

In part, Metro is a victim of its own success. On an average weekday, about 750,000 trips are taken on Metrorail. Each of those customers typically rides on two escalators per trip: one from the street and one down to train platforms.

According to Metro spokesman Steven Taubenkibel, these units take a tremendous pounding day in and day out. Inevitably, what is going to happen is “they are going to require maintenance.”

And many of Metro’s escalators are more than 30 years old.

Managers at Metro are still studying the incident Monday at the Dupont Circle Station south entrance, where passengers fled a smoky escalator by climbing up a shut-down and under-repair escalator stairwell. The passengers at the top had to vault over the escalator handles to exit the station.

Metro managers say a plan to repair much of the Red Line includes money for a thorough rehabilitation of all three escalators at that station entrance. That work is expected to begin in the fall.