Google on Tuesday trumpeted the development of a fully self-driving car—no human intervention necessary. "They won’t have a steering wheel, accelerator pedal, or brake pedal… because they don’t need them," project director Chris Urmson wrote on Google's blog, calling the car "an important step toward improving road safety and transforming mobility for millions of people." Google co-founder Sergey Brin was no less emphatic in an interview with the New York Times. Asked about car companies' advances in automatic steering for traffic jams, he said, “That stuff seems not entirely in keeping with our mission of being transformative.” The implication: Google is the only company transforming how we travel in America.

But Google, to use a technology cliché, has chosen the wrong platform. If the company wants to revolutionize mobility, it shouldn't waste its time with cars. They're intractably inefficient uses of energy and space, and building our communities around them has failed.

The internal combustion engine is laughably inefficient. Between 70 and 85 percent of the energy created by burning gas never gets put to use moving your car. The biggest inefficiency is heat loss, which immediately claims about 60 percent of the energy in burning gas. Even relatively dirty fossil fuel–fired power plants can be about 55 percent efficient through engineering modifications that aren’t possible in a four-door sedan. Gas-fueled cars emit about three times as much carbon per passenger mile as mass transit (commuter rail, subway, buses). Google’s cars are electric, but even the best electric cars still fall short of the energy efficiency of comparably advanced buses and trains. And in regions with particularly dirty power supplies, the carbon footprint of electric cars is no smaller than gas-powered cars rated at 31 to 40 miles to the gallon.

Mass transit isn't simply more energy efficient. Passenger cars are huge wastes of space—visually, the comparison is comical. Google’s promotional video shows its driverless, horseless carriages zipping around empty suburban office parks, but this isn’t what driving looks like to Americans. Driving is a miserable experience inflicted upon 86 percent of us every morning and every afternoon, five days a week. Much of this misery is due to the presence of other people’s cars—speeding alone through an evergreen forest is an advertising fantasy. Real transportation innovation has to solve the problem of space. There’s never enough of it where you want to drive, when you want to drive there.

The notion that hundreds of thousands of Google car pods will glide through cities in humming packs just inches apart is deeply naive. Almost every major city in the U.S. contains the rebuttal to that idea, in the form of new freeways that ere supposed to relieve congestion and improve commute times. When it comes to roads and traffic, more supply means more demand: If you build it, the drivers will come. Conversely, if you make driving more expensive and time-consuming, people will seek more efficient, greener alternatives. London knows it and Mike Bloomberg wanted New York to find it out: the best thing you can do to reduce traffic jams is to give people a reason not to get into cars in the first place. Driverless cars, summoned by an app like butlers by a bell, do the exact opposite. As Wes Siler writes at Gizmodo: "It's one more car, not one less” (emphasis his).