This blog has been a bit obsessed both about the benefits of dynamichighwaytolling to controlcongestion, and about economic distortions caused by “freeparking. Apparently, our two pet obsessions have cross-bred, producing this San Fransisco Weekly article on dynamically-adjusted parking fees.

Here’s the basic idea: new, inexpensive remote sensing technology is coming online that could…

…precisely monitor activity in a city’s parking spaces, so a computer might figure out how much parking meters should charge so 15 percent of the spaces remain empty—the optimum amount, research has shown, for making it convenient to shop by car.

In other words, if parking in a given neighborhood is looking tight, sensors would note the fact. Then, the parking meters would know to raise their prices a bit, until about 15% of the available spaces freed up. If there are lots of free spaces, then prices would come down a bit, letting people park for longer without racking up big fees. Ideally, the prices would self-adjust so that they’re “just right”—not so expensive that there are too many free spaces, and not so cheap that parking is difficult to find.

One jurisdiction is already committed to trying out the system:

[T]he idea of closely monitoring empty and full parking spaces and subtly adjusting meter prices … was a principle untried anywhere in America—until last month, when Redwood City approved a plan, developed by the city’s downtown development director, Dan Zack, to do just that.

The article also notes that local shopkeepers—who tend to object to proposals to meter parking—often drop their opposition if the parking revenues are used locally to clean streets, improve sidewalks and lighting, and the like. That way, the money raised by parking fees never strays too far from the meter.

It could be easy enough to paint this sort of proposal as “anti-car.” But it’s really not. Yes, it would probably make parking more expensive; but it also could make parking more convenient and less time-consuming. That’s a tradeoff that in many cases would make sense—both for people who own cars, and for cities that are trying to control runaway congestion.