San Francisco Spends $25 Million To Test 'Goldilocks' Parking : Planet Money A high-tech system will adjust the price at parking meters based on real-time information. The aim: To make prices just right.

San Francisco Spends $25 Million To Test 'Goldilocks' Parking

San Francisco is about to spend $25 million to answer a simple question: How much should a city charge for parking?

The price should be cheap enough that most of the metered spaces and city parking lots are always almost full.

But it shouldn't be so cheap that spaces are entirely full, leaving drivers frustrated and adding to congestion as cars circle endlessly looking for a place to park.

"It's the 'Goldilocks' principle of parking spaces," said Donald Shoup, a professor of urban planning at UCLA who wrote a book called "The High Cost of Free Parking."

Shoup's work was the inspiration for a high-tech project San Francisco is launching today. Its aim: to set parking prices just right.

The system will use electronic sensors to measure real-time demand for parking spaces, and adjust prices accordingly. When there are lots of empty spaces, it will be cheap to park. When spaces are hard to find, rates will be higher.

"It's basic supply and demand," Shoup said.

The range in prices will be huge: from 25 cents an hour to a maximum of $6 an hour, according to the San Francisco Municipal Transportation Authority.

Eventually, drivers will be able to find open parking spaces by going online, checking their mobile phones or reading for new electronic signs that will be posted throughout the city. (Warning to SF pedestrians: Watch out for drivers who are checking their phones to search for a parking place.)

Today's first phase begins with the installation of 190 new meters in the Hayes Valley area of San Francisco. Over the next two years, the city will be testing the system at 6,000 metered spaces across city and at 12,250 spaces in 15 of the city’s parking garages.

"It's good for commerce and getting the price right," Shoup said, pointing to the economic efficiency of the plan. "Let the market do something good for this service."

For More on Shoup: Check out his "Shoupista" following on Facebook.