Ontario

I think this is the difference - you're assuming a distracted driver is only a danger to pedestrians. Big mistake.

The op's chart shows a difference in speeds, not a difference in incident rates; you've inferred higher and/or more serious incident rates from a speed chart. If I wanted to outright attack the argument my line would be "was there any measure of speed before and after in areas outside the camera's capture zone"; since most drivers appear to just slow down for the camera and re-accelerare after. One could argue the chart shows no change in driver behaviour, merely driver performance in an enforcement area. You're conflating the metric (speeds measured before and after in the same spot) with what it should measure (driver compliance to the law when using the road).