SSS 2008-09-15（在线收听）

This is Scientific American's 60-Second Science. I'm Karen Hopkin. This will just take a minute.

If you spent any time in your car this summer you probably sat in some traffic. Maybe you’re in a jam right now. If so, a study in an upcoming issue of Physical Review Letters might help pass the time. According to scientists, building new roads won’t make traffic any lighter. It could even make things worse. What might help, though, is shutting a few streets down.

Imagine that there are two routes that take you to work: one a long wide freeway and the other a short, narrow bridge. In this example, everyone’s drive time would be minimized if half the motorists took the bridge and the other half the highway. Of course nobody cares about minimizing the collective commute. Every driver wants to get there first. So some of the highway drivers will switch to the bridge, thinking that’ll be quicker. When the bridge backs up, some will head for the highway. The upshot of all this back-and-forth is that everyone’s commute takes longer—in real life, up to 30 percent longer, the physicists find. The solution, they say, is to close off a few carefully selected avenues to limit all that to-and-fro. With less choice, and less chaos, everyone moves faster. It sounds counterintuitive. But it could beep worth a try.

Thanks for the minute for Scientific American's 60-Second Science. I'm Karen Hopkin .