ATLANTA — Atlanta city leaders helped celebrate an expansion at the world’s busiest airport in Atlanta on Wednesday.

Five new passenger gates are now opened Hartsfield-Jackson Atlanta International Airport as part of the Concourse D expansion project.

Atlanta Mayor Andre Dickens joined officials for a celebration marking the milestone.

“Starting tomorrow, ATL’s passengers will walk along into this larger area, larger gate area with upgraded restrooms and spaces that will move people more efficiently,” Mayor Dickens said.

The new gates will help smooth passenger flow. The concourse is being redesigned using modular construction, with each section built off-site and then rolled into place, officials said.