Does not work. Tried it a little while ago. Was 10kmph over on a up hill downhill section. Even with no offences for over 10 years and then only ever minor ones.
What irks me the most is it is for seconds not continued or deliberate speeding and on a fairly steep downhill section.
Yet what annoys the crap out of me you can have a truck or car / trailer / caravan doing 110 on the hwy that are supposed to be max 100 kmph and day in day out get away with it as the speed camera does not differentiate and a heavy haulage vehicle speeding is way more dangerous.

