I despise speed cameras almost as much as I do any "traffic calming" measures. There is one at the point where the southbound M11 acquires a 50mph limit just before the junction with the North Circular A406.
Despite its reputation as the most profitable such installation in the count(r)y, I still regularly see it triggered off by drivers with insufficient wit to recognise that a camera warning sign, a 50mph sign, a bright yellow camera box and white painted stripes on the road might be an indication that a little slowing down would be in order.
As to speed humps, of whatever design, they cause more problems than they cure, as those who live beside roads where they are installed, ambulance drivers and anyone with a small car with little ground clearance will confirm. Perhaps they are one reason why you see so many inadequate drivers in unsuitable all-terrain vehicles in cities these days.
Must go and return my hobby-horse to the local Morris dealer.