It focused on the Arizona study because that was the only one out of the 35 that actually measured Motor Vehicle Collisions. The rest did not even attempt it in any controlled manner.
As stated, there are no meaningful studies that these cameras reduce accidents.
I am in fact stating that there is no proof that they do anything to reduce collusions or deaths. I stated in my first comment that such proof does not exist.
These cameras are only deployed to generate revenue. There is no scientific basis for improved safety.