NYC DOT’s plaza program hit a milestone today, when officials cut the ribbon on a block of Willoughby Street reclaimed from car traffic between Pearl and Adams Streets in Downtown Brooklyn. What used to be, essentially, a private parking lot for government placard holders, is now the first plaza program project to make the transition from temporary materials to permanent construction.

The 14,000 square-foot plaza, set in motion in 2006 with a street reclamation by Iris Weinshall’s DOT, was folded into DOT’s Plaza Program after Janette Sadik-Khan took charge of the agency. It then entered the capital project pipeline for the Department of Design and Construction, which raised the plaza to the same grade as the sidewalk and worked with DEP to replace water mains.

The project cost $2 million, paid for by federal Congestion Mitigation and Air Quality funds. Congresswoman Nydia Velázquez was on hand for today’s ribbon-cutting, along with Sadik-Khan, DDC Commissioner David Burney, Downtown Brooklyn Partnership President Tucker Reed, Jeff Kay of Muss Development, and Borough President Marty Markowitz.

“It’s a pleasure when the commissioner and I can be on the same side of a project,” Markowitz said, before launching into a gregarious bit inviting the single people of Brooklyn to make the plaza their new meeting spot.

The overall theme this morning was not match-making, but retail sales. Sadik-Khan cited research showing that plazas help improve retail sales, adding that DOT expects to release a complete study of those effects this summer.

The research underscored what’s become obvious on the ground. Since the plaza was installed in 2006, Muss Development has leased the first two floors of a city office building on the north side of the block and converted it to retail use, opening a Panera Bread, while Shake Shack opened a restaurant on the plaza’s south side in 2011.

The plaza will continue to be maintained by the MetroTech BID, a division of the Downtown Brooklyn Partnership. Partnership president Tucker Reed is no stranger to pedestrian plazas: As head of the DUMBO BID in 2007, he was at Sadik-Khan’s side when the city launched its plaza program.

Today’s ribbon-cutting was the first but by no means the last. “All of the plazas are going to enter the permanent construction process,” Sadik-Khan said after the event.

Update: Take a trip down memory lane with this proto-Streetfilm about the reclamation of this plaza in 2006…