Pulled over

Parents know that sometimes the chance for reward is a more powerful child obedience method than the threat of penalty. "Clean your room or your grounded" can be less effective than, "Clean your room and we'll go get ice cream."

A recent National Highway Traffic Safety Administration study shows that when the stick is combined with the carrot, drivers behave much better. The study placed GPS trackers to measure speed in eight cars loaned to 50 different drivers for a week each. The drivers were told that, at the end of their week, if they kept their speed within the posted limits, they would be paid $25 each. Every time a driver went over the speed limit by five to eight mph, he would lose three cents. If the driver's speed exceeded nine or more ticks above the posted limit, he lost six cents.

If the drivers were caught speeding by the cops they got speeding tickets as usual.

Each time the car's ignition was switched off, drivers got a report showing how much their lead feet had reduced their rewards.

The results were promising, with one driver saying he had made a game out of trying to keep his $25. NHTSA officials involved in the study say insurance companies might be very interested in implementing the program for their customers.

"We found that the incentive system was incredibly effective in getting drivers to reduce their speeding," Ian Reagan, a traffic safety researcher at NHTSA tells NPR. "Egregious speed limit violations were almost eliminated – that's driving nine or more [miles per hour] over the speed limit."