Several posters here have asked the question "what is the point of speed-bumps". That they should even ask the question is rather sad, but to think they might actually not know the answer is really quite tragic!
They exist in order that others that do not drive may also exist in the same street. Try crossing a rat-run street with kids, and you will understand. It might seem odd to those that want to rush through residential areas, but yes, other people actually exist. Some of them infirm and a little slow in body or wit, others (go forbid) may even be children (how crazy is that - allowing children to exist outside the house, and NO I do not mean toddlers).
No-one really like speed bumps but the alternative is to allow drivers the freedom to nip through at speed (and at times 30mph is too fast), while removing the freedom of movement to many others. It's a simple choice really, and it is solely the drivers that have caused the need for speed bumps.
See, quite easy to understand when you think about it rather than just rant on
Oh, wait a minute - I forgot. It is up to everyone else to watch out they don't fall foul of a simple mistake - and if any kids make a simple error of judgement, well that's entirely their own fault so there. That is the motorists' moto isn't it??