The following info was in an interesting article I read recently.
*Before anyone has a go at me, I am not agreeing/condoning any form of speeding or law breaking, it’s just an interesting situation. 
A chap called David Edgar is currently legally and technically challenging the admissibility of evidence obtained from Gatsometer speed cameras. This bloke is a retired Consultant Engineer and former professional Inventor as well as having studied and practised both civil and criminal law for almost 11 years.
Gatso’s operate by taking two photo’s, 0.5 secs apart, over a measured distance, then calculate the speed. David Edgar has developed his own (very accurate) ‘flash measuring device’ which has found that 80% of Gatso flashes are 0.63 secs apart, which creates a discrepancy of 26%, well outside the permitted UK tolerance.
The courts are being very awkward etc with regard to this evedence being presented and as you can imagine, if ever this was allowed to be presented in a test case, there would be literally millions of motorists who would be able to appeal their convictions, fines and endorsements and potentially sue the Government for compensation!!
There was a lot more info in the article I read and I believe that this bloke has a website, currently under construction, but due to go live any day. Bookmark www.notsoaccurate.com and check back later.
If anyone wants to know where I saw this article, PM me.
*** Just an after-thought; this maybe ties in with the recent case of a discrepancy between a Gatso issued speeding ticket and tacho evidence. I believe the speeding ticket was cancelled (on appeal) and the tacho was accepted as evidence.
