I think your thinking is right on. Speed cameras only temporarily cause drivers to drive slower, but they indirectly force drivers to drive more vigilantly so as to not get a ticket. I often see drivers speed, then slow down when they see a camera and then speed up again when they’re out of the camera’s view. But, just my opinion, that’s more reassuring than having drivers use some of the multi-lane avenues like a highway while texting or looking at IG.