Placemeter, a start-up that bills itself as an urban intelligence platform, officially launched Tuesday. Its co-founders believe they can provide better information to retailers, city planners and governments at a fraction of the price of traditional methods of counting foot traffic.

Placemeter takes video feeds from streets and creates automated reports tracking the number of pedestrians. They say they’ll soon offer information on the speed of pedestrians, so for example, a store could see if a new sandwich board out front is appealing to potential customers, and slowing them down as they walk.

“To optimize how things work, you need to quantify, you need to measure,” said Placemeter co-founder Florent Peyre. “It’s that same idea that you would have online where you’re constantly testing and iterating designs to see what works. We’re bringing that element of quantification and science.”

Understanding cities is increasingly valuable given how Americans and people around the world have gravitated to them. In 1900, 39.6 percent of Americans lived in urban areas. That grew to 64 percent in 1950 and 80.7 percent in 2010. With modern tools, such as cheap cameras and algorithms, that can detect pedestrians, cities can be better and more cheaply understood than ever before.

“Everybody’s talking about smart growth. Everybody’s talking about multi-modal. But we don’t have data for those things,” said Lee Kim, who focuses on New York City pedestrian and transit analysis at the environmental consulting firm AKRF. “The numbers we’re using right now are outdated.”

Kim reached out to Placemeter last year because she wanted to track traffic at a Manhattan intersection where an estimated 7,000 people cross in an hour.

“My hope is with this initial pilot study that we’re doing, we’ll be able to establish a good enough sense on how actual trip generation is for an area,” Kim said.

She sees a lot of potential value in real-time data on the number of people entering and exiting different buildings. So far, Kim said, it’s too early in her study to have any results and see if the technology is succeeding.

Placemeter’s cameras can track pedestrian traffic 24-7, year-round. The approach delivers more data and fresher insights then relying on a team of humans to count traffic for a day or two. Chief executive Alex Winter said that a store could use its existing security cameras on the Placemeter platform, provided they support streaming video.

Cy Bessiere, managing partner at Palais des Thes, which has two tea shops in New York, has been using Placemeter for a few months as a beta tester. He had always estimated 80 percent of the foot traffic to his SoHo store came from the East, due to the presence of a major street, West Broadway.

But after looking at the Placemeter data from a camera outside the shop, he learned that only 60 percent came from that direction. With more potential customers coming from the West, Bessiere added a new display on the West side of the shop in hopes of luring those customers. So far, he said, he hadn’t seen the new signage impact his sales.

The shop also shifted an employee from working Saturday to Friday because it found traffic was actually higher then.

The technology raises privacy concerns for some, given the presence of cameras that record and monitor pedestrians. Placemeter says it only uses its video feeds to identify the presence of a pedestrian, and doesn’t use its technology to identify specific individuals. Aside from 0.1 percent of its videos that are saved for quality assurance, the rest are discarded after being processed and converted into reports for customers.