The cameras work on a trigger mechanism activated by cars travelling above the speed limit. The camera, using a flash, records two images, half a second apart, enabling police to work out the vehicle's speed. The cameras, housed in protective boxes, will be perched on poles in the central reservations of major roads.
Here we tell you all you need to know about the cameras:
Will the cameras be used to monitor offences other than speeding?
No, says Supt Chris Leithead, of the Metropolitan Police traffic headquarters. They are only triggered by speeding cars. 'But if you're driving a clapped-out heap that ought not to be on the road, we might pay you a visit.'
Will the cameras be signalled so that I know they are there?
No, but you will know cameras are operating in the area.
Can I be prosecuted more than once for speeding past a series of cameras on the same journey?
Very unlikely if the cameras are yards apart. But if you went past four cameras on different sections of the M1 at 90mph, you could be committing four separate offences - and lose your licence after a single day's speeding.
Can the camera see in the dark?
Perfectly, says Supt Leithead.
Can the camera distinguish between similar number plates?
Definition is 'superb', according to Supt Leithead. But the AA says: 'We have been calling for safeguards. The police should check that you do own the type of car shown on their photographs.'
How many boxes will have cameras in them?
About one in eight. But they will all have flashes. In London, the police aim to set up about 400 boxes over the next few years.
What do I do if I am convinced I wasn't speeding?
Go to court and plead not guilty. But expect the police to produce a barrage of experts testifying to the brilliance of the cameras and telling magistrates about the computer technology that never lies. You might think twice before doing this.
What if someone else was driving the car?
Tell the police. Failure to do so carries the same penalty as speeding. And bosses beware: if an employee takes the company car without telling you, is pictured speeding and doesn't own up, the points go on your licence.
If I already have several points on my licence, what is to stop me pretending that my partner was driving?
Nothing at all, except that your partner might take exception.
Will a photograph be sent to my home? It might tell my partner I was in the wrong place at the wrong time.
A photograph is sent if you plead not guilty. If your relationship suffers, tough.
Can I foil the cameras by dirtying my number plates?
Yes, but it's an offence to have unreadable number plates.
Can I go so fast that the picture is too blurred?
Yes, but only if you're Nigel Mansell. At 120mph the pictures still come out.
Who has access to the films?
They will be stored by the police traffic unit but can be passed to other parts of the police service and 31 other organisations, including the secret service, according to civil liberties groups.
Can the information be passed to private detectives?
Any officer who did so would be sacked, say police.
Will the information be destroyed?
Yes, when no longer required.
Could the information be used in other prosecutions, for instance to suggest that a suspect had been near the scene of a crime?
Can the cameras be trained on my back garden?
No, they are fixed to face the road - although they can be turned on to either carriageway.
Are the cameras vandal-proof?
No, but they're 'bloody strong', says Supt Leithead. And how will you know you're vandalising a box with a camera inside it?
Do the cameras take pictures of everyone going above the speed limit?
No. But police are reluctant to say how fast you must go before triggering them.
Will cameras make it safer?
Yes, say police. In Victoria, Australia, they brought a 21 per cent reduction in casualties and a 30 per cent drop in deaths.
Can the cameras be foiled by plates that reflect the flash?
No, says Supt Leithead. Yes, says Allan Wilkins of Magic Plates, an Oxfordshire firm that makes reflective plates. We took the photograph below of a normal plate and a reflective plate using a flash - but our darkroom warns that, under certain conditions, the numbers might show up. In addition, lawyers wonder whether the reflective plates are legal.Reuse content