Ten miles of roads. Fifteen Philadelphia neighborhoods. No motor vehicles.

A year after Pope Francis' visit led to road closures in central Philadelphia, the city's new Philly Free Streets festival will replicate a narrow sliver of that "traffic box," which sounded scary at the time but ended up being pretty chill.

Walkers, bikers, runners, skaters, and shoppers - everyone but drivers - are invited to "come out and play" from 8 a.m. to 1 p.m. Saturday on South Street between the Schuylkill and the Delaware River. The no-car route runs up the Schuylkill River Trail to Martin Luther King Jr. Drive and into West Fairmount Park.

"He's a pretty quick walker," warned Clarena Tolson, deputy managing director for the Office of Transportation and Infrastructure Systems.

Managing Director Michael DiBerardinis will lead a 8 a.m. bike ride departing from the same location.

Other activities include group running, yoga, boot camp, dancing, scavenger hunts, and a concert. The idea is to connect the city's parks and trails and get people moving in a city with high rates of diabetes, heart disease, and hypertension, Tolson said.

"If they don't know how to ride a bike, come out and learn to ride a bike," she said.

During the five-hour event, SEPTA buses and other traffic will be able to cross South at 10 intersections staffed by police. West Philadelphia traffic will be minimally affected.

Tolson said the city did not invite outside vendors, essentially creating a "no-compete zone" for existing businesses.

"We want them to engage and enjoy the fact that they have so many guests in their community," she said.

Philly Free Streets is a family-friendly event, so smoking is "strongly discouraged," according to its website. Alcoholic beverages are prohibited.

The nonprofit Open Streets PHL launched a petition campaign for the closures and met regularly with city officials after Francis' visit.

"I used to love going to Summer Streets when I lived in New York City, so I had known about it for a while and hoped we'd get something like that in Philly," said Jon Geeting of Open Streets PHL, referring to a New York car-free street event.

"Then, when the pope visit happened, it became clear there was a really positive response to the car-free streets, so it looked like there could be a good opening for a campaign."

Geeting said he'd like to see the program grow, with at least three events next year in different parts of the city.

"The block-party culture in North Philly and West Philly is so strong, and we think this event would be especially popular in neighborhoods in those areas," Geeting said.