Here's one more reason it won't work.
The cameras were designed to catch motorists who simply slow down in front of a camera, and then drive above the speed limit until they reach the next one.I still don't like it, but sounds well thought out so far.
But, under Home Office rules governing the camera equipment, prosecutions are only valid if a driver is filmed in the same lane at the start and finish of each section by a linked pair of cameras.The Chief Constable of the Yorkshire police adds:
That means a three-lane motorway would require three separate sets of cameras - one for each lane. If drivers leave the speed-camera zone via a different lane to the one they entered in, they cannot normally be prosecuted.
Motorists are strongly advised not to seek to evade detection by unnecessarily changing lanes as this would generate a greater risk of collision and may lead to other offences being committed which the police may prosecute.This is the a different version of the problem seen with red light cameras--people accelerating massively when they see a yellow light to avoid a ticket.
I think it's clear that such systems don't work, but that's doesn't stop people from trying.