The SPECS average speed camera systems utilises state of the art automatic average speed digital technology, which not only calculates and records the average speed over a given set distance, but also uses an Automatic Number Plate Reading (ANPR) video system.
That set distance could be between two cameras, creating a Speed Control Zone, or between several sets to form a Speed Control Network. In addition, the cameras are each fitted with infra red illuminators so they can operate at night or at times of poor daylight.
At present, they are most commonly found on dual carriageways and motorways, as
they are able to monitor up to four lanes of traffic at any one time. There are
some SPECS systems in place on single carriageway routes too, such as the A628
route in South Yorkshire.
The cameras themselves are usually found on gantries above the road, either positioned at the roadside, or in the central reservation. This allows them to maximise their capture rate - they can capture three vehicle images per second. As a result, the cameras have earned the nickname of "yellow vultures".
Originally they are only approved for measuring speed in one lane - so if you're travelling down a dual carriageway and change lanes half way between the cameras, Home Office regulations meant that you could not be prosecuted if you exceed the speed limit. However, that has since been rectified as the Home Office gave approval for the SPECS system to be used for measuring speed along the stretch of road, regardless of how many times the driver changes lanes.
How the system works
As the vehicle passes each camera, its registration number is read, photographed and digitally recorded. The time the vehicle takes to pass between each pair of cameras is then recorded, where the data is then transferred to an enforcement cabinet.
Here, the ANPR system matches up the vehicle's corresponding images, and using the date and time stamp carried with each image, the system calculates the vehicle's average speed. If the vehicle is recorded as exceeding the speed limit, the cabinet automatically generates a Violation Record.
This record includes a black and white image of the registration plate, a colour image of the vehicle, the date and time, location and average speed between the two cameras.
The records are then stored on a large capacity storage drive held within the enforcement cabinet until downloaded - and the penalty notice is then issued.
The system in pictures
 |
 |
| Vehicle passes
the entry camera: registration number is recorded |
The entry
camera: just a single black and white unit |
 |
 |
| Vehicle passes
the exit camera: registration number is recorded |
The exit
camera: black and white (left) and colour (right) units |
Permanent SPECS locations
| Road | Location | Speed Limit |
| M3/M25 | M3 Junction 2 / M25 Junction 12 | 70 mph |
| M60 | Junction 25, Stockport | 50 mph |
| A14 | Cambridge to Huntingdon | 70 mph |
| A38 | Saltash Tunnel, Cornwall | 30 mph |
| A43 | Weston Favell, Northamptonshire | 50 mph |
| A46 | Cotgrave, Nottingham | 50 mph |
| A46 | Fandon, Nottingham | 40 mph |
| A52 | Bingham, Nottingham | 40 mph |
| A52 | Saxondale, Nottingham | 60 mph |
| A60 | Sherwood, Nottingham | 30 mph |
| A60 | Central Nottingham | 30 mph |
| A66 | Bassenthwaite Lake, Cumbria | 50 mph |
| A77 | Ayr to Stranraer | 60/70 mph |
| A100 | Tower Bridge, London | 20 mph* |
| A102 | Blackwall Tunnel, London | 30 mph |
| A127 | Basildon to Southend | 50/70 mph |
| A130 | Benfleet, Southend | 60 mph |
| A149 | Sutton to Potter Heigham, Norfolk | 60 mph |
| A228 | Isle of Grain | 40 mph |
| A282 | Dartford River Crossing | 50 mph |
| A428 | Brayfield-on-the-Green, Northamptonshire | 60 mph |
| A537 | Macclesfield to Buxton (Cat and Fiddle) | 50 mph |
| A610 | Nuttall, Nottingham | 30 mph |
| A611 | Annesley, Nottinghamshire | 30 mph |
| A616 | Stocksbridge, South Yorkshire | 60 mph |
| A631 | Scaftworth, Nottinghamshire | 50 mph |
| A631 | Gringley on the Hill, Nottinghamshire | 50 mph |
| A1203 | Limehouse Link, London | 30 mph |
| A3211 | Lower Thames Street, London | 20 mph |
| A6514 | Aspley, Nottingham | 30 mph |
| A6514 | Basford, Nottingham | 30 mph |
| B6004 | Basford, Nottingham | 30 mph |
| Northern Ireland | ||
| A1 | Newtownards | 60 mph |
| A2 | Belfast to Bangor | 60 mph |
* - also enforces an 18t weight limit
Location and speed information from Speed Check Services.