Actually don't worry. I can see whats happened here.

I'm afraid there is no realistic prospect of challenging this easily if you cannot deny truthfully that you were speeding.

Laser guns are more open to challenge than GASTO devices its fair to say. Mostly those arise from the fact that they are mobile though and so affected by location and method of operation. However, with such a wide gap between the speed limit and the level at which you were traveling there is no reasonable prospect of challenge.

The distance you mention is not going to give rise to a challenge.

There has been damaging case law a few years ago on this point anyway which basically just says that the device in question no longer even needs to be a prescribed device as long as the Bench find it reliable which they will given that you were nearly double over the speed limit.

There's no obligation to advertise a detection device of any kind. That is a complete myth. They are perfectly free to hide behind overgrown bushes and catch motorists by stealth. What they cannot do is obscure the speed limit signs in any way. That would give rise to a challenge but thats not what they've done here.

Sorry thats probably not the answer you wanted but it is the position that you face and I have a duty to inform you truthfully.

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