Types of speedtraps
Types of Speedtraps used in the UK, As of January
Radar or Laser
Non Radar or Laser
Radar, Laser and Speedtrap
Speeding Offence Codes and Speeding
Speed detection using radar was pioneered by Maurice Gatsonides, he was
a rally driver who wanted to measure the speeds of rally vehicles, this
turned into a business. Hence Gatso cameras.
Gatso Camera, Fixed Installation Post (FIP)
Usually has an 800 frame roll of film(some may now be using digital cameras).
Operates on K Band.
When a vehicle exceeds a preset speed threshold, the device is activated
taking two photographs half a second apart. The photographs show the date
and time of the offence, together with the speed recorded. The unit takes
between three and four hundred readings of a single vehicle as it passes
through the beam. There must not be a greater speed variation on all of
these readings of more than two miles per hour or the device will abort
These can also use the TruVelo system or the inductive loop system.
Initially developed as a red light camera but has recently been made an
addition to the arsenal of speed cameras, the Monitron works in a similair
way to the Gatso cameras, above. There are sensors placed in the road
in front of the camera and when a speeding car passes by the camera takes
a picture. The main difference to the Gatso is that the Monitron uses
a digital camera which then stores the images in a nearby device. Once
the memory is full this is then automatically downloaded and wiped so
the capture process can start again. The only way to detect this type
of camera is via a GPS unit.
Mobile Gatso Cameras, Mobile Installation Post
This is a complete FIP camera but mounted on a trailer. It costs around
£9000 and is towed into position, typically in road works. It can be deployed
in around 15 minutes. It has the same box on top of the pole as a normal
FIP, and hence works the same (radar, 800 frame roll of film etc.). The
ruler markings on the road are the only difference, the police don't paint
these markings on the road each time, so they are superimposed on the
pictures. However they do paint the road in some areas, like long term
SPECS, SVDD (Speed Violation Detection Deterrent)
Super efficient, 2 cameras with infra red that are linked to a computer
that has number plate recognition, if the same number plate appears at
the second camera within a given time period then it will calculate the
average speed over the distance, if the speed is over a given threshold
an NIP (Notice of Intended Prosecution) will be issued. All this can be
automated by the computer technology it has, it can dial into DVLA for
the driver details, and send an automated NIP with all the details and
digital image, it won't run out of film like a Gatso can.
A company called Speedcheck will operate the system and so free up officers
to chase real criminals. However this also means that because of the reduced
police presence on the roads the nutters who keep to the speed limits
but are just very bad drivers (such as the centre lane owners club) won't
get stopped at all.
Motorcyclists are not affected by this system as it is forward facing
so can't read a motorcyclists number plate. Square and dirty number plates
can give the system problems.
uses three Piezo sensors installed in the road surface at known
distances apart. When a vehicle passes over the sensors, two speed
measurements are taken, the first between sensors 1 & 2, the other
between 2 & 3. As with other systems if the difference between the
two speeds is
greater than 2 mph the reading is regarded is void. The sites are normally
manned and the equipment is connected into a nearby Haldo pillar where
the sensors are terminated.
Truvelo use a similar principle but use
four Piezo sensors. The distances
are as follows:
1 - 3 = 1.53 m
2 - 4 = 1.53 m
There are a few different setups available to the
Piezo sensors are installed in the road ahead of
the post. When a vehicle
passed over the sensors two speed measurements are taken primarily between
& 3 and 2 & 4. However the camera unit is a bit more intelligent
dummy flash and actually double checks itself by taking measurements between
1 & 2 and 3 & 4. Again if the two speed measurements are more
than 2 mph
different then the measurement is classed as void. There are three white
lines after the sensors which act as secondary check lines. Similar to
Gatso lines in principle and are required by ACPO to prove that there
is a second way of confirming the speed and you are not just relying on
the radar or sensor measurements. The middle white line is 1.8 metres
from the last sensor, the other two are 18 cm before, and 18 cm after.
This is to allow for a 10% margin of error. Because this distance is exact
the camera will take a photograph of the vehicle when the front axle (wheel)
is on the middle white line. The camera knows your speed and therefore
when to take the photograph.
Same principle but the sensors are placed after
the post in the direction of travel. Speed measurement is the same and
the first photgraph is taken with the wheel on the white line. A second
photograph can be set to be taken either 1/2 sec later or when the vehicle
has travelled xxft. Using Gatso style lines it is then possible, depending
setting, to prove that the vehicle was travelling at that speed. There
are only two known locations where this system is used.
A15 Brant Road, Lincolnshire
A51, Tamworth, Staffs
Four sensors again and the setup is much like DS2.
Installed in the road
and with white lines the camera is attached to a tripod and run from a
battery. Manned, the officer can then sit in a car and keep an eye on
equipment. Rear photography is also possible using the above method. There
is also a remote control available ( a box on the end of a piece of wire
plugged into the cable) allowing the user to alter the speed threshold
for HGVs etc. NB: Becuase the Truvelo system cannot tell the difference
between different vehicles HGVs travelling on roads where their speed
is further restricted cannot be penalised. They would have to be travelling
over the normal threshold for other vehicles.
Four Piezo tubes are placed across the carriageway
at the same standard distances. A camera is connected and then it is active.
This is not yet used in the UK, it uses 2 infra red beams and 2 reflectors
in the road, the beam is broken to activate it, giving speed, direction,
the distance from the previous car, even the car length.
Cat's Eye Camera
Solar powered and already in use in America and South East Asia, feelings
are that this is not yet proven technology for the UK and still has a
long way to go, the government has commented that it is happy with it's
current developments on speed cameras. More
Very accurate but the beam does spread out to 3 ft at 1000 ft distance.
When used over 400 yards they need to be tripod mounted for stability
and are often used in a van, such as thes Cheshire 'Safety Camera Speed
|Cheshire Safety Camera Speed Enforcement Vehicle.
||2 Cheshire Safety Camera Speed Enforcement
||The video and speed offence recording equipment.
||The laser gun with digital speed readout and
Readings can be taken in a fraction of a second.
It needs a flat reflective surface such as a number plate or even a headlight.
The device must be calibrated once a year by the manufacturer and also
at the start and end of each shift by the officer with a calibrated speedometer.
The distance to the target must be a minimum of 10 times the height from
Popular in Kent, Manchester, Cheshire and Wales forces, but fast becoming
the most popular form of mobile trap across the country. The device can
be switched for oncoming or receding vehicles. On an interesting note
the Lti 20-20 has been banned in certain American states as the shake
effect when using a heavy hand held device can affect it's accuracy.
This can be supported on a small tripod about a metre off the ground.
Hidden next to unmarked cars, Motorway bridges and in the bushes. They
are very accurate. K or Ku band. However police now prefer Laser devices.
Vascar (Visual Average Speed Computer And Recorder)
Set at a minimum distance of 1/8 of a mile. The trap could be white
squares or round markings on the road but could be any fixed objects of
a known distance apart. A police officer uses a time recording device
to record the length of time it takes a vehicle to travel through the
speedtrap, once this has been done it is a matter of time over distance
to calculate the drivers speed. This could even be done from a helicopter
or an officer on foot. As this is largely down to human judgement there
is a tolerance for the officers reactions. The tolerance is the same at
each end of the reading so the reading is thought to be accurate enough
for a prosecution.. This can be used in conjunction with video for a safer
This is an in car video system which can be used for recording
poor driving behaviour and then be shown to drivers to demonstrate their
errors, it can also be used in court to support the officers statement
An officer can simpy follow a speeding vehicle using a calibrated speedometer
this must be done over at least 2/10 of a mile.
This is a hand held stop watch calculating and indicating speed. It can
be used on foot.
An officer can make use of special markings in the road, police motorcyclists
like to use them because of there portability being hand held.
Bus Lane Enforcement Cameras
Not quite a Gatso, but in some cities Bus Lane Systems are being used
to monitor bus lanes, using Gatso style systems with inductive loops or
Inboard Bus Video Systems. (The Video fitted on the bus can usually be
seen fitted on the front in the middle area of the bus, a 9" square
black window gives it away.) These cameras watch out for offending vehicles
using the bus lane to drive down or park in. Offending vehicles get an
NIP in the post.
In use around London they are proving very effective in convicting drivers
that use bus lanes.
This is one of the standard laser guns used by the British police forces
AutoPatrol PR100, Ka band 34.6 GHz
High visibility speed cameras
are to become the norm, starting with Norfolk region then, Cambridgeshire,
Cleveland, Derbyshire, Essex, Lancashire, Lincolnshire, North Wales, Northamptonshire,
Nottingham, South Wales, Staffordshire, Strathclyde, Thames Valley and
Warwickshire. the cameras will be painted bright yellow and signs will
have to be positioned according to the guidelines. They must be visible
from a distance of 66 yards in a 40mph limit and 109 yards in areas above