Up the speed limit

[SPman]

Mix the two for a lethal cocktail - happening all the time, on a road near you!

[svs]

That is more to do with how the unit is designed to operate, eg on 'Top Gear' they stated that UK GATSOs MUST take 2 x pictures of your vehicle in order to issue an infringement notice...some cars can go fast enough to be out of frame before the second shot.

UK cameras take 2 pictures 0.5 seconds apart so that in court, they not only have the radar speed but you can also work out the speed from the difference between the two pictures. There are often distance markings on the road.

Last I saw on top gear test was that driving a car past a gatso at 170mph, then it simply failed to go off at all - no mention of being out the frame for the second shot.