Taken from www.ukspeedcameras.co.uk

"Laser: Now the most popular mobile method of entrapment as laser is so good.
Typical uses of laser include motorway bridges, van's at the side of the road with the back doors facing you or open, tripod mounted or handheld.

Laser can operate at a mile to a mile and a half and if very accurate and very fast.
Officer records your speed, numberplate automatically within a few seconds."