So, if you have received a section 172 notice through the post you will see that you are required to say who was driving at the time, and that if you were driving you are required by law to admit this or that if someone else was driving you are legally required to state who this in fact was. This can be a source of extreme worry and concern for some people when they are not entirely sure who was driving at the time.. they may share the car with members of their family, partners, spouses, siblings etc and it may be the case that they can not categorically say for sure who the driver was at the time.
The form, due to its wording, actually states that if you were the driver tick this box, if you were not the driver tick the second box and tell us who was driving. But what are you supposed to do if you are not sure? You could argue that it is actually impossible to fill in the form in that case (unlike the scottish version of the form which has a third option where you can explain the problem if you are not sure) This can often be the main point of a defence strategy, as long as what is termed reasonable diligence applies during the presentation of the information to the police and the whole matter is handled in a civilized and courteous manner, there is a strong possibility that you will be able to get the case dismissed on these grounds.
So this is a piece of information not generally known to people outside of the motoring law world as they would normally just assume it applies to them and accept the penalty without contesting. This is definitely the most effective way to evade the prosecution if of course, you do actually share the car with other drivers and of course, that you are not sure who was driving at the time.
Obviosly the best way to avoid being prosecuted is not to get caught speeding in the first place and there days the most effective way to do that is to be pre warned of oncoming speed cameras before you zoom past them, so if you buy a SatNav it's just about the best way you can do this. TomToms especially are extremely good for letting you know before you are within range of a speed camera and therefore the best way to avoid prosecution in that case.