Have to say, Tombie is right, they are voluntary,
I've lost my licence 6 times, all for being a hoon, all these offences I have committed and none were so lame as 6km/h over the limit, NEVER had an infringement from a camera, fixed or mobile, these are voluntary actions, to speed past the car on the side of the road
Coppers on the other hand, don;t charge you for these lowly speeds, more like 10km+
BUT, Camera ARE revunue raisers, they place them in 4 lane, slowly descending, industrial roadways, NOT where they belong

i.e., school zones, built up residential housing areas, hospital/medical access, commercial centres, they'e are always where people can inadvertantly speed
Haven't had an infringement in over 3 years now..........except for one Unreg, when I had a permit, didn;t like when I told him he was a sphincter

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