This may not be useful in the UK but I am about to mount a case over here in Australia using the most simple of defences. I am not the first to use this defence and others have been successful. I am using the most fundamental foundation of our legal system.
Innocent until proven guilty
beyond reasonable doubt.
I knew the camera was there, and not just because my Road Angel told me. I pass it regularly and have been booked by it in the past - although the cameras were found to be defective and the charge was dropped.
I had just purchased the Road Angel and was actually regularly looking at it as I approached and passed the camera. My speed had been constant for at least 500m so the GPS was giving a true indication of my speed.
My defence is simply that I checked both of my speed measuring devices and both of them indicated I was travelling within the speed limit. Under our laws it is impossible for the magistrate to find the case proven as I have introduced reasonable doubt.
The speed was witnessed by my wife as well, just in case I need corroboration.
I was detected doing 88kph in and 80kph zone and charged with doing 86kph. The Road Angel indicated 79-80 and the speedo indicated 82-83 - subsequently checked and found to be reading 3kph higher than actual speed.
Our tolerance is a total discrace - 8kph equates to 5mph so 55mph in a 50mph limit and after allowing a 2kph error factor means I was booked for exceeding the speed limit by 3.75mph - or barely the width or the speedo needle.
AND I WASN'T EVEN SPEEDING
