Stockholm experimented with rewarding compliance while punishing free-riders: if you drove at or under the speed limit, you would be entered into a lottery where the prize fund came from fines that speeders paid. The so-called speed camera lottery is the perfect solution for facilitating behavior change on the roads.

Kevin Richardson entered Volkswagen’s The Fun Theory competition in 2010 with his idea about the speed camera lottery. The concept was so powerful that Stockholm temporarily put it to the test a year later. When your car passes by a specific crossing, a camera snaps a photo of it and measures its speed. If the driver was above the speed limit, a fine was imposed. However, the money was used to enrich a unique fund, the lottery prize for obedient drivers. If you were not a speeder, you could participate in the lottery, and you had the chance to win some money from those who didn’t follow traffic rules.

It’s simple and brilliant. Sticks and carrots are on an entirely new level. It punishes free-riders and rewards behavior benefiting the entire community through a fun game. No wonder Sweden was eager to put the idea to the test. Twenty-four thousand eight hundred fifty-seven cars passed the cameras in the trial case, and the average speed limit was reduced from 32 km/h to 25 km/h (by 22 percent).