Local councils have a degree of freedom to choose what traffic calming methods they use, and they will usually decide this based on what the requirement is in terms of speed reduction. More aggressive speeds bumps require drivers to slow down more, so it would suggest that this area in particular has a problem with speeding.

There are specific regulations for the dimensions and placement of speed bumps. You can read these in detail on lesgislation.gov.uk website, but the key points is 'the highest point on it is not less than 25 millimetres nor more than 100 millimetres higher than an imaginary line parallel to the centre line of that carriageway connecting the surface of that carriageway on one side of the road hump to the surface of that carriageway on the other side of the road hump and passing vertically below that point.' We wouldn't suggest you physically measure them yourself as this could be dangerous, but if they meet these regulations then there is not a great deal you can do.

There are no regulations we can see regarding impact rating, because ultimately this is determined by the speed at which a vehicle makes contact with it. If you have suffered suspension damage because of hitting a speed bump then you can complain to the council on this point, but it will be up to you to prove that the damage has occurred because of the design or construction of the road hump, and that it had nothing to do with the speed at which you made contact.