According to new data only around half of fixed speed cameras on British roads are switched on.
The figures that were released by 36 police forces in the UK show that of a total 2,838 cameras, just 1,486 - or 52% - are active. (Fixed cameras only not mobile devices)
according to information obtained by the Press Association (PA), some police forces have completely turned off all their cameras. Northamptonshire police deactivated all of theirs in 2011 but left the machines in place as a deterant. (Cleveland, Durham and North Yorkshire said theirs are all also turned off)
A spokeswoman for the National Police Chiefs' Council said the decision to use cameras was "an operational matter", adding that "all forces have individual responsibility for their use of speed cameras".
Fixed speed cameras in Cleveland, Durham, North Yorkshire and Northamptonshire are all inactive
Staffordshire Police has 272 fixed cameras across the region, of which 14 are active
In Scotland, less than 29% of fixed cameras are switched on
Forces where less than 25% of fixed cameras are active: West Yorkshire, Kent, South Yorkshire, Greater Manchester and Cheshire
Derbyshire force operates 112 cameras, of which 10 are switched on
Gwent police force has 17 fixed speed cameras of which 8 are active while South Wales has 88, 59% of which are switched on
Police forces with all fixed speed cameras switched on include: the City of London, the Metropolitan Police/Transport for London, Lancashire, Nottinghamshire, Suffolk and Northern Ireland
Edmund King, president of the AA, said: "Many of the empty yellow cases are due to cuts in road safety grants and the fact that digital cameras, although more effective, are very expensive."
He added: "It has long been the case that cameras were moved between sites, depending on need. When it comes to the chances of being caught on camera, it is a postcode lottery. All cameras in City of London and Suffolk are working whereas only 5% are active in Staffordshire."
"However, drivers should remember that lack of a yellow fixed camera doesn't mean they are immune from mobile hidden cameras. Best advice is stick to the limits rather than gambling on the yellow boxes."