Three long escalators had to be pulled out and replaced in a tight work space. (Metro photo)

The transit authority announced that it plans to allow riders to use the new escalators at the south entrance to Dupont Circle station starting Sunday. A “ribbon cutting” ceremony is scheduled for noon, Metro said.

Come Monday, this could affect the travel habits of thousands of Red Line riders who have been confined to the station’s north entrance and exit for the past eight and a half months while the three long escalators on the south side were replaced.

Though the performance of Metro escalators is infamous, the transit authority usually chooses to repair them, rather than replace them. That’s how bad these three were.

The replacement job was a difficult one, partly because of the confined work space. The three-escalator bank is in a spot that had been designed for two units. Another complicating factor was the safety plan that needed to be put in place before the work  could proceed.

At all times, there had to be one unit in there that could be used as an emergency staircase in the event the station needed to be evacuated. The smaller escalators between the platforms and the south mezzanine were kept in operation, even though the mezzanine was closed, in case they were needed to move riders in an emergency. Extra police and Metro staff were kept at the station to either quickly fix one of the remaining escalators or to aid in crowd control.

Back in February when the south exit closed, Metro officials said they expected the job would be done in October. Even before this month started, riders began writing in to ask if Metro had set a date. But until Friday, officials had said only that it was on schedule to open during the month.

Among all of Metro’s many reconstruction projects for 2012, this was one of a handful that got the most attention. General Manager Richard Sarles is scheduled to be at the entrance, at 19th Street NW just south of the circle, for the ribbon-cutting on Sunday.