It's not about safety, it is, pure and simply, about revenue. It costs far less to put up a camera and send out citations than to pay a cop (revenue enhancement agent) to sit at the stop light and write citations. Traffic laws are not about safety, they are about money, period. That is why cops are told "If you are doing your job you should be able to write (fill in the appropriate number) traffic citations a month". Been there, done that, bought the T-shirt. It didn't fit!
Boonie Rat
MACV SOCOM, PhuBai/Hue '65-'66
However, it is known that where red-light running is a problem, a small increase in the time a yellow light remains yellow before it turns red will markedly reduce dangerous road conditions and thereby obviate the need for cameras entirely.
Consider the policy of some companies that supplied and installed the cameras they set the yellow-light time duration a bit less and-or set the switch from all four sides red -- which is normally about 2.5 to 3 seconds -- to perhaps 2 seconds. All sanctioned by the government either by direct approval or neglect of oversight, the government -- in particular the politicians that passed the traffic camera laws -- in fact do make the intersections more dangerous.
The bogus timing of intersection lights was exposed in the media about a year ago and the article(s) were posted on this forum.