The first red light camera ticketing system was installed in New York City in 1993. So by now you would expect that there is conclusive evidence of whether they reduce accidents.
Indeed, the primary benefit cited in support of launching the program was they will avoid accidents, reduce injuries and even save lives. Some cite a NYC study of 82 red light cameras that found a 16% drop in injuries after cameras were installed including a 44% in pedestrian accidents.
In contrast, Los Angeles City auditor Wendy Greuel found that L.A.’s program (now discontinued) didn’t necessarily reduce traffic collisions.