A year after Philadelphia officials announced widespread street closures in advance of Pope Francis' visit - provoking, at first, widespread consternation - the city on Friday released plans to open a seven-mile stretch of roadways to pedestrians for an open streets festival next month.

Last August, with preparations for the papal visit reaching a fever pitch, residents had panicked over a planned "traffic box" in Center City that would close most of the downtown area to cars.

But by the weekend of the papal visit, the traffic box was a hit. Residents wandered, wonder-struck, through empty streets and took selfies in the middle of the Ben Franklin Bridge. A campaign was launched to get the city to do it again - this time, for the sole purpose of letting residents walk through car-less streets once more.

On Sept. 24 - the same weekend that the pope visited last year - the city will close streets from Front Street to West Fairmount Park. Organizers announcing the route at a news conference Friday said the festival, called Philly Free Streets, is a direct outgrowth of the unexpected delight residents took from the papal traffic box.

"We saw how nice it was to have people walking," said Councilman Mark Squilla, whose district encompasses part of the festival. "And how you see the city differently."

Philly Free Streets will close off the entire length of South Street between the Schuylkill and Delaware River between 8 a.m. and 1 p.m. on Sept. 24. The route will snake from South Street up the Schuylkill River Trail, along Martin Luther King Jr. Drive, and into West Fairmount Park, passing through 15 neighborhoods along the way, the Mayor's Office said.

Some thru streets will allow traffic to cross South Street. Police officers will be stationed at select north-south streets along South Street to wave traffic through at intervals, and event organizers are working with SEPTA and the police department ahead of the event, city officials said.

MLK Drive already is closed to traffic on weekends from April through October. But the larger Free Streets festival will station fitness activities and pop-up educational programming along the route, and is hoping to encourage shopping along the South Street corridor.

"Smart cities around the world are doing this," city managing director Mike DiBerardinis said.

A map of the event route is available on phillyfreestreets.com.