Pebble at Sidewalk Labs is working with the city of Philadelphia to create bookable loading zones to improve traffic flow in Center City, as well as improve safety for pedestrians, cyclists, and drivers.

Starting Oct. 17, 21 zones throughout Walnut, Chestnut, and Sansom streets will be available to reserve through the Pebble Driver App, the city announced Monday.

According to Smart Cities Director Akshay Malik, once drivers are within half a mile of a loading zone, they’ll be automatically assigned to an available spot…

Users will be charged up to $3 an hour. Drivers who park in Smart Loading Zones without reserving the space could be ticketed or even towed.

Mike Carroll, deputy managing director for Philadelphia’s Office of Transportation and Infrastructure Systems, says this program won’t eliminate congestion completely, but could be another tool to limit the number of drivers blocking traffic.