In New York City Mayor Bloomberg is trying to crack down on speeding and other dangerous driving related offences. In order to do this he is pushing for traffic cameras on every corner. Automated tickets generate millions of dollars in revenue every year. A side effect of this is that the number of traffic accidents at intersections and areas with these automated systems decrease as people drive more safely to avoid tickets.
http://www.autoblog.com/2011/08/24/nycs-bloomberg-wants-traffic-cameras-on-every-corner/