Some 12,000 Americans die every year in traffic crashes caused by speeding, according to government statistics. Officials have tried many strategies to get drivers to slow down. And now they might have found something that works, after researchers placed a GPS device inside cars that gives drivers an incentive not to speed.
Traffic safety experts have tried using big flashing signs to tell you how fast you're going. (The psychological subtext: Drivers are rational, and they will slow down if they know how fast they're going.)