Traffic is one of those things, like sea levels and our working memory, that we just assume is getting worse with time.

Unless we live in a hollowed-out shell of a city like Detroit, traffic - and getting stuck in it - has been one of steady and ineluctable increases. Despite building bigger roads and in some cases expanding transit options, cars are still clogging the highways and lengthening our commutes.

Yet a growing number of planners and transportation wonks believe the wave has crested and, in the developed world at least, we have reached what they call "peak car." In many places, they note, vehicle miles traveled per person have declined steadily in recent years.

Earlier this month, civil engineer David Levinson wrote a blog post on the topic framed as a piece of future history. Datelined November 2030, it asked the question: "What happened to traffic?" It paints a picture of a world where today's worries about traffic growth are as misguided as those of the 19th century urban planners who thought the biggest obstacle to city growth was the amount of horse manure the transportation system created.





Add to this the forecast of far fewer trips to the store as people order more and more of their household goods online. Someone has to deliver that stuff, of course, but one UPS truck replaces lots of family minivans on the roads. There's more: People are likely to cluster in cities and get rid of their cars, relying on car sharing for weekend jaunts and trips to Ikea, and the fact that they have to pay per trip means even fewer trips. The rise of 3-D printing-on-demand means less shipping and therefore fewer trucks on the road.

It's far from clear that all of this will come to pass - the death of the commute has been proclaimed before - and there's no assurance that working more from home means working less. In fact, there's evidence that the expansion of work into home has only increased the number of hours people work. At the same time, given the choice between working a bit more and spending more time in transit - whether it's in a car, a train or a levitating hypersonic capsule - many people would likely choose more work.

Drake Bennett is a Bloomberg Businessweek reporter. E-mail: