@Ed1: all speed bumps are not the same
They are supposed to be, though - there are standards for this sort of thing, same as there are for bollards, chicanes etc. That said, it is rather harder to measure the profile of a speed bump than the height and spacing of bollards or chicanes.
IIRC the council did have to get the contractor to re-do the speed bumps around the Buckstone estate because they were too severe, but it took the residents a fair bit of effort to get ECC to accept that the problem existed. I suspect that a fair few more would be found to be non-compliant if checked. (Sometimes, when the road is clear and no-one is around, I experiment driving with my car's cruise control set at a GPS-verified 20mph. Some of Edinburgh's speed bumps are really quite fierce at that speed.) I quite like speed cushions for some use cases, but too many of them seem to suffer from sinking of the brick paving approach and departure slopes, so they end up more like stepped kerbs. Again, something that should be addressed by the original contractor but - as with inadequate reinstatement of road surfaces following road works - all too often not pursued by the local authority.