RACHEL MARTIN, BYLINE: Self-driving cars are almost here. Or so we keep hearing from tech companies and their supporters. Some people swear these cars will revolutionize how traffic works. Others fear that more crashes are just around the corner. Few people, though, stop to ask about the implications for parking. To explain, we're joined by NPR's social science correspondent, Shankar Vedantam, who apparently is asking this question (laughter). So what's the deal, Shankar? What's the problem with self-driving cars and parking?
SHANKAR VEDANTAM, BYLINE: Well, on the surface, Rachel, we don't think of self-driving cars in the context of parking. But that's part of the problem. When we think about self-driving cars or autonomous vehicles, we usually think about using them to get someplace. We don't think about what happens once we get there.
VEDANTAM: I spoke to someone who has thought a lot about this. Here is Adam Millard-Ball at the University of California, Santa Cruz.
ADAM MILLARD-BALL: Autonomous cars can certainly easily evade a two-hour parking limit. They can just move themselves every two hours. They might even not have to pay the meter if they look and see whether an enforcement officer is coming.
MARTIN: What? Wait, can they do that? They can discern whether or not a law enforcement officer is coming?
VEDANTAM: It's not clear whether they'll have the AI to be able to discern whether a law enforcement officer is coming. But clearly, if they're self-driving cars, they don't actually have to park at all. They can drop you off at a restaurant while you go have lunch. And while they wait for you, instead of parking, they can simply drive around. Now, you might say that could be costly in terms of the amount of gas they would use.
MARTIN: Right, just inefficient.
MARTIN: And, you know, carbon footprint, et cetera.
VEDANTAM: But there would be a way around that. Self-driving cars could create their own traffic jams.
MILLARD-BALL: And so in a place like downtown San Francisco that might be latching onto existing traffic jams, turning onto the most congested street every time they can make a turn or, more subtly, to try and find each other, to coordinate so you have this lazy river of slow moving cars that just want to drive as slowly as possible.
MARTIN: All these automated vehicles just, like, on slow cruise?
MARTIN: Making a traffic nightmare.
VEDANTAM: Precisely, and quiet residential streets could become a parking lot. In other words, you get dropped off at lunch at a restaurant downtown. And then your car drives itself to the nearest residential area to avoid paying for parking.
MARTIN: The cities aren't going to be happy because they're not going to get parking revenue, right?
VEDANTAM: Precisely. Millard-Ball's modeling experiments show that self-driving cars can effectively blur the line between parking and driving. Most cities currently charge drivers for leaving their vehicles on city streets, not for driving their vehicles on city streets. Because self-driving cars might drive around as a form of parking, Millard-Ball thinks that cities should move to create congestion pricing, as some big cities have done, where you get charged for the amount of time that your car spends on the road whether or not it's moving.
MARTIN: I mean, plus, wouldn't it just be a public nuisance? If you were living in one of these residential neighborhoods and you look outside and there's, like, some weird self-driving car just doing loops around your neighborhood, that's creepy.
VEDANTAM: Exactly, and Millard-Ball has done these modeling experiments in San Francisco. And he shows that San Francisco traffic is going to be even worse - hard though it could be to imagine - than it is today.
MARTIN: Oh, man. The future is coming, like it or not. Shankar Vedantam, he joins us regularly to talk about social science research. You can listen to more of his work on the podcast that he hosts. It is called Hidden Brain. Thanks, Shankar.
VEDANTAM: Thanks, Rachel.
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