Companies looking to test package or food delivery robots on San Francisco sidewalks will have a more difficult time in the future.

According to a report from the San Francisco Chronicle, the city's Board of Supervisors this week unanimously passed tough new regulations that "limit companies to three robots each; limit the city to nine robots total; and confine robots to industrial areas where almost no one lives." On top of that, robots being tested on city sidewalks can go no faster than 3 mph, and a human must be present to monitor the machine.

San Francisco Supervisor Norman Yee and supporters originally wanted to ban robots — like the ones from Yelp partner Marble — from the city's sidewalks altogether, as is the case with Segways and bicycles, according to the Chronicle. Yee and pedestrian advocacy groups reportedly "said they want to prevent sidewalk crowding and protect seniors, children and disabled people."

But the Chronicle noted that the regulations may also be fueled by concern over automation stealing jobs away from humans.

"As more and more people start to lose jobs to automation you'll see this kind of response," Vanderbilt Computer Science Professor Douglas Schmidt told the news outlet.

Marble has been testing its delivery robots in San Francisco's Mission and Potrero Hill neighborhoods in partnership with Yelp's Eat24 service. The waist-high robots feature ultrasonic sensors, cameras, and other technology to monitor their surroundings.

If Marble and other companies find San Francisco's new rules too restrictive, they won't have to travel too far to find locations that offer a more lenient stance towards robots. A number of nearby cities – including Redwood City, San Carlos, Sunnyvale, and Concord – have embraced robot pilot programs, as have states like Idaho, Wisconsin, Virginia, Florida, and Ohio, the report notes.

Meanwhile, across the pond, Domino's has already enlisted robots to deliver pizzas in Germany and the Netherlands. If those trials are successful, Domino's could expand the service to more of its 2,000+ stores worldwide.