Metro riders who rely on the Dupont Circle station may want to rethink their commute — or budget in extra time for getting into and out of the D.C. station.

The transit agency plans to close the south entrance of the station at 19th Street Northwest starting on Wednesday for nine months, forcing the more than 22,000 who board at the station each day to go through a single entrance. Thousands more exit from it each day.

That’s a big bottleneck for one of the busiest and deepest stations in the system.

The agency has said it needs the time to replace all three escalators, which measure 188 feet in length. Keeping the entrance open while lifting heavy equipment into and out of the narrow station mouth would be too dangerous, they have said.

The escalators, installed 15 years ago, are among the system’s most unreliable. They were custom-built for the space by a company that no longer makes escalators, making replacement parts hard to come by.

The agency is trying to calm riders who remember a near-stampede in July 2010 when a fire blocked one Dupont entrance and riders swarmed to the other entrance to find a partially barricaded escalator.

Officials say that one stopped escalator will be kept accessible at the closed entrance at all times in case of emergencies. A new spiral staircase has been added to a vent shaft as another way for riders to escape during emergencies. An empty train will be parked on a nearby pocket track to help evacuate riders from the station if needed.

But Metro officials warned that during a “service disruption,” agency police may have to close the sole remaining entrance for safety reasons and have trains pass through the station without stopping to prevent dangerous overcrowding.

One side benefit of the project, though, is coming to other Red Line riders: work at nearby Farragut North station  has been temporarily suspended during the construction.