I was startled a few weeks ago to hear the urban sustainability director of a large city bemoan the fact that the community's schools require students to learn how to drive. The logic was simple: if fewer people know how to drive, there will be less driving and less driving helps will have grown to 2 million members.

Driving these trends are several factors: Environmental awareness, the shocking spike in gasoline prices, and the cost of owning a car at a time of high unemployment. Much of this was acknowledged by Bill Ford Jr., executive chairman of Ford Motor Company. "I certainly knew 30 years ago when I joined the company that the consumption of natural resources and the pollution that our industry was causing were unsustainable." But for many years, consumers were not demanding fuel-efficient vehicles and the auto industry didn't have the technology to deliver fuel efficiency and the strong vehicle performance consumers wanted. "We are at a confluence now. We have ever-increasing fuel prices, and technology that is a game-changer and can be introduced affordably."

And Ford acknowledged another trend-setting factor: the demand for and emergence of new "urban mobility" solutions. "If you look out into the future, there are going to be 50 cities in the world with 10 million people--30 of which are not going to be in Europe or the United States. They are going to require mobility solutions that probably don't include individual car ownership on a large-scale basis, simply because the cost of owning a car in the city is going to be too expensive." Ford envisioned a day when urbanites would consult their cell phones to identify the most direct or cheapest way to get somewhere. "It could be a combination of bus, subway, taxi, car-share, bicycle or walking. That customer can have a blend of transportation to get them to that destination."

What about not training new drivers? Obviously, it makes sense not to require that urban teenagers learn how to drive, especially when more and more alternatives are emerging. And it could make sense not to pay for their driving lessons with public funds.

But it seems unlikely that in the near term the size of the driving population will keep increasing--by millions of new drivers each year. Besides, the availability and quality of urban mobility systems is highly uneven. 

What matters is not whether teenagers know how to drive. What matters is to build the seamless, affordable urban mobility systems that Ford described--and to do it as quickly as possible.