Devon is home to dozens of fixed speed cameras which are well sign-posted with warning signs along the road, bright-yellow boxes to house the cameras and clear markings on the road.
At the same time mobile patrols often take to our roads using handheld camera devices to catch speeding motorists at a number of locations across the county.
But what drivers may not know is that there are also 20 'secret' speed cameras at sites across the county which could catch you out if you're going too fast.
The cameras are 'speed on green' devices which are used to catch people crossing red lights at busy junctions in Devon.
But when the lights are on green, these ameras switch to detecting speed, meaning if you go through the junction too quickly you will end up with a ticket - even though you probably didn't know there was a speed camera there.
Here are all the 'hidden' locations.
EXETER
A377 Alphington Road
A3015 Topsham Road
A3015 Holloway Street (Acorn)
B3181 Heavitree Road
SOUTH DEVON
A380 Penn Inn Roundabout, Newton Abbot
A380 Newton Road, Kingskerswell
A3022, Newton Road, Torquay
A3022 Newton Road, Torre
South Street, Torquay
A3022 Kings Drive, Torquay
A379 Dartmouth Road, Paignton
NORTH DEVON
A361 Braunton Road, Barnstaple
PLYMOUTH
A374 Exeter Street (west)
B3413 Crownhill Road
A386 Outland Road
A374 Exeter Street (west)
Wolseley Road
Mannamead Road
Plymouth Road
B3396 junction Alma Road and Milehouse Road
HOW THEY WORK
Gatsometer BV, manufacturer of the UK's Red LightCameras, (named Gatso RLC 36) has been producing RLC's since 1966. The RLC system is triggered by sensors or ground loops that are cut into road surface as a vehicle passes over them, while a red light is shown.
The Red Light Camera was originally used to measure red light offences. Now the RLC can also be used in combination with speed measurement, similar to that of a Gatso Meter rear facing speed camera (radar type 24 technology) and can therefore also record the speed of the offending motorist as well.
Red light cameras are placed at traffic light controlled junctions and photograph vehicles that pass traffic lights set to red. The camera is triggered from inductive proximity sensors placed within the road surface.
The detector triggers when a car passes over the loop - if the traffic light is also set to red, then the camera is triggered to take two photographs 1 second apart. A data box is included in the photograph to show the date and time of the photographs, the speed of the vehicle as it passed the red light and, if necessary, a road lane identification.
