frankv:gished: So the consensus seems to be no, because most speedos over compensate. That's fine, good to see it generated some discussion.
Was I aware I was going over the limit? Yeah possibly, if it was where I think it was - I drove just under 1k km's that week so it's hard to say definitively but there were times where I would look down and realised I'd crept over the limit and slow down. It also didn't help that I started using the satnavs gps as the odometer.
Whilst I guess there's no doubt about the *legality* of fining people for going 5kph over the limit, I think there is still a question of fairness.
Do car speedometers *always* over-compensate? Given that the rolling radius of your tyres will vary more than 5% over the life of the tyre (let alone with varying pressures due to varying temperatures), I still think that the small tolerance isn't fair.
Incidentally, given that you have a GPS, you *could* use the GPS as a far more accurate speedometer than the one in your dash.
Also incidentally, (and perhaps getting back to the forum's purpose) 6 or 7 years ago I read an article about a number of software bugs in cars, which included one motorcycle whose speedo would read low by as much as 25kph. And a car (BMW IIRC) whose ABS system would under some circumstances prevent the brakes from engaging when the pedal was pressed.
As speedos in many vehcles often read quite a bit over what speed you are actually going, your speedo was likely showing that you were going over 5km above the limit anyway. I say just pay the fine and move on. They often have small tolerances especially around schools, so it isn't uncommon for people to be pinged for going 5km over. Can't believe this thread has got so long over such a small fine. Life isn't supposed to be fair. It is up to you to make sure all your speedos etc are reading correctly. If you don't think the camera is accurate, I believe you can ask for it's current certificate, if you want to dispute it. Also I doubt a GPS is more accurate for measuring speed, as they have quite a large margin or error, and it would be well out when you are going up a hill.