feedback loop comprises four stages: evidence, relevance, consequence, and action. Once you recognize this, it’s easy to see why the radar speed displays’ exploitation of the loop works so well. Drivers get data about their speed in real time (evidence). The information gets their attention because it’s coupled with the posted speed limit, indicating whether they’re obeying or breaking the law (relevance). Aware that they’re speeding, drivers fear getting a ticket or hurting someone (consequence). So they slow down (action).