Because I am certain that I have been falsely accused of breaking the speed limit but have been denied the evidence when I requested it.
Currently if you receive a speeding fine resulting from a speed camera you are not allowed to see the evidence unless and until you go to court. You have the choice to accept a fixed penalty notice or dispute it without the normal 'habeous corpus', you are asked to take on faith that there is evidence to support the allegation of an offence.
Supporting evidence i.e, the photographic evidence from the speed camera and the speed calculations should be sent out with the penalty notice. You could then be sure that you had committed an offence, currently there is no way that you can be certain that it was your vehicle which tripped the camera so you might be forced into paying a fine for an offence you have not committed.