When you are driving around Baton Rouge, you've probably seen signs that have your speed shown in flashing lights. Safety experts thought that if drivers knew how fast they were driving, that they would be more likely to slow down and avoid car accidents.

When that didn't work, traffic safety experts installed hidden cameras on major roads. Their rationale? If drivers knew they were being watched but didn't know when, they would slow down and drive more cautiously all the time.

That hasn't worked either. Now, traffic safety experts think they've solved the problem regarding the most effective way to encourage drivers to follow posted speed limits.

In a recent study, researchers placed a small GPS device in a driver's car. The GPS constantly measured the car's speed against the posted speed limit. At the end of each week, drivers who stayed within 5 mph of the speed limit received $25. Each time drivers were more than 5 mph over the speed limit, money was taken from their reward.

One of the researchers at the National Highway Traffic Safety Administration said the incentive system was "incredibly effective" at getting drivers to reduce their speed. He said, "Egregious speed limit violations were almost eliminated -- that's driving nine or more [miles per hour] over the speed limit."

Although the study found an effective way to encourage drivers to slow down, paying drivers $25 each week is not a plausible or sustainable plan for the government.

There are currently some insurance companies that use similar devices to monitor the driving habits of the insured. It will be interesting to see whether they start using devices that provide real-time feedback.

Source: npr, "GPS Study Shows Drivers Will Slow Down, At A Cost," Shanikar Vedantam, June 21, 2012