Having said that, there are some pretty suspicious placements that seem like clear revenue raising. For example, a new underpass was built here in Adelaide on a road leading into the city. It has a relatively steep incline and the road curves as you enter and exit the underpass. There's a speed camera placed in precisely the best place to catch people who happen to stray a few kph over the speed limit as they descend into the underpass, and it makes that underpass difficult to go through - you're aware of the camera so you're constantly watching your speedometer as you enter and exit, and as I mentioned before, the road curves and so you find yourself drifting over the line because you can't focus entirely on the road for fear you'll creep over the speed limit and get a $600 fine and a bunch of demerit points.
There have been a few crashes on the underpass already, although thankfully no fatalities as far as I know.