They don't do much here really, not enough to calm people down. Medicine Hat they do, and traffic speed is way more even.
Look at where they use them here - they pick places where the speed limits are lower than the traffic flow. With the Whitemud flowing at 90-100 and limits set at 70-80, they're going to take lots of pictures. Where 137 ave ends in the west, the road is a massive divided road and it's a 60 zone, traffic flows at 80 - so they park the camera on top of the overpass and take pictures like crazy.
In St. Albert it's horrid. They installed red light cameras and found few people were running the lights so the private company that was contracted wasn't breaking even. So they had the city shorten the amber phases to create more red light infractions. The same for our speed limits. The main road running through the city used to be an 80 zone. Then it was reduced to 70, but we still weren't speeding enough to generate enough tickets, so now it's a ridiculous 60. Six lanes, divided, all controlled intersections.
Then, to make it worse, they retimed the lights on that road, calling it "traffic calming" so now you have to stop at pretty much all of them as you make your way through town. They hoped (we know, duh) that it would encourage speeding as you can make the lights if you drive 80. Also, it would help with increasing light running as people would push the ambers to try to not have to stop at every light.
Everything is done here in the name of creating violators.