Red-light cameras make big money for cities, delivering more tickets at lower cost than human officers ever could. But the cameras also apparently save lives: a 5-year study by the Insurance Institute for Highway Safety found that intersections with such cameras had about 25% fewer fatalities, the Washington Post reports. "Our traffic fatalities have been cut in half in four years," said DC's police chief.
The study, along with anecdotal evidence from law enforcement, suggests that people drive slower because they know the camera is always watching. "We see less high-speed crashes, we see less crashes at what used to be the worst intersections," said the DC chief. "Because of speed enforcement, when people do crash, it's at a slower speed, so there are less likely to be fatalities."