NHTSA's GPS experiment docked speeding drivers cents from a $25 prize — it worked

Traffic officials had tried everything to slow drivers down: big flashing signs (drivers stayed rational-ish), police on your tail (too rare), hidden speed cameras (resented and localized). Meanwhile about 12,000 Americans a year were dying in speeding-related crashes. The next iteration, as NPR reported in June 2012, put the cop inside the car — and a psychologist in the back seat.

In a proof-of-concept experiment partly funded by the National Highway Traffic Safety Administration, researchers installed a small GPS device that constantly measured the car's speed against the posted limit, paired with a financial incentive: a $25 prize promised at the end of each week of safe driving. Every time a driver went five to eight mph over the limit, 3 cents came off the prize; nine or more mph over cost 6 cents.

The results were dramatic. 'We found that the incentive system was incredibly effective in getting drivers to reduce their speeding,' said Ian Reagan, a traffic safety researcher at NHTSA. 'Egregious speed limit violations were almost eliminated — that's driving nine or more miles per hour over.' Some drivers turned it into play: at least one made a game of trying to keep the full $25.

The design's edge was real-time feedback: every time drivers turned off the ignition they were told the 'cost' of that trip — unlike insurance rebates for good driving, which arrive months later and never sting. Reagan thought insurers might one day offer such tracking devices to drivers who want lower premiums.

Give drivers a $25 weekly prize and shrink it in real time: lose 3 cents for going 5–8 mph over, 6 cents for 9+ — small accumulating losses drivers actually feel.

Decades of tools — signs, patrols, cameras — failed to change driving behavior durably.

Psychology research long showed people are vigilant about small, accumulating losses, the 'ticking meter' phenomenon.

The penalty sizes were tiny but immediate, so the cost of speeding stopped being hypothetical.

For some drivers the prize became a challenge to protect, adding a game frame to the financial one.

People are more vigilant about small, accumulating losses than about rare large fines — and framing can turn rule-following into a game players want to win.

As of the June 2012 report the system remained a proof of concept. Reagan suggested insurance companies might one day supply the devices to drivers seeking lower premiums; unlike the rebates insurers then offered, the device gave real-time per-trip feedback.