In your Ford or other fine automobile, you will be led, as if by an invisible hand, to reduce congestion, even though that was no part of your intention. And in Washington state they've got the data to prove it:
For about eight months, drivers in 275 Seattle-area households agreed to pay for something the rest of us get for free: The right to drive on the region's freeways and streets.
They were guinea pigs in a pioneering study that explored how motorists' behavior might change if they had to pay tolls — not just on a few bridges or highways, but on almost every road with a yellow center line.
Researchers established virtual tolls ranging from a nickel to 50 cents a mile. They gave participants pre-paid accounts of between $600 and $3,000, and told them they could keep whatever the tolls didn't eat up.
The experiment ended in February. Preliminary results, released this month, suggest that if such so-called "road pricing" were widespread, it could make a significant dent in traffic.
....The promise of keeping some of that money proved to be a powerful incentive. Nearly 80 percent of the participants drove less than they did before, or they changed their routes or travel times to avoid the highest tolls, said Matthew Kitchen, the study's director.
When the study was finished, the average payout was nearly $700 per household.
When other variables are factored out, Kitchen said, participants took 5 percent fewer auto trips and drove 2.5 percent fewer miles each weekday because of the tolls.
The drop was even more dramatic during peak-traffic periods, when tolls were highest: 10 percent fewer trips and 4 percent fewer miles in the morning, 6 percent fewer trips and 11 percent fewer miles at night.
Participant Kathi Hardwick, an executive assistant at a downtown Bellevue bank, started riding the bus to work from her home in Bothell. It wasn't as convenient as driving, she said, but it saved her about $5 each way in tolls on Interstate 405.
She also began combining errands and driving less on weekends.