Speed cameras have been put in at various intersections across the globe. Depending on who you ask, they were put in to bring in money or to reduce accidents. But here's one reason why they don't reduce accidents as much as we think they do.
In the past we've talked about how extraordinary results cause people to believe that their "luck" is going one way or another. There is The Gambler's Fallacy, which causes people to think that, if a coin has landed on one side an unusual number of times it is "due" to land on the other side on the next flip. Conversely, there's the hot hand's fallacy, which causes people to think that a person who has shot dice successfully a few times is on a hot streak and will keep shooting well. In fact, both hot streaks and cold streaks are part of the normal course of events. A coin flipped many times will have long streaks of heads or tails. A die thrown enough times will come up lucky for long streaks in a row.