A survey carried out by Mori in 2001 has suggested that drivers who use speedtrap detectors are 24% less likely to have an accident and on average also travel far more miles. Mori report. You will need Adobe Acrobat Reader to view the report.
Types of trap
Broken down into 2 main types
1. Static :- Gatso, Truvelo, SPECS, and other variations.
2. Mobile :- Laser - more common, Radar - now rare.
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 calculating time over distance to acquire the vehicles 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 prosecution. It could also be a police officer following in a vehicle using the same kind of system, again distance travelled over time taken, sometimes used with Provida.
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 if needed.
An officer can simply follow a speeding vehicle using a calibrated speedometer this must be done over at least 2/10 of a mile.
SPECS, SVDD (Speed Violation Detection Deterrent)
Super efficient, 2 cameras with infra red lamps for night operation 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 do.
A company called Speed check operates the system and so frees up officers. 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 on motorways) 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.
3 rubber hoses set into the road across they carriageway, either manned or unmanned. It is linked to a video device. Hoses are set 1M apart, not to be confused with traffic counting devices which only have 2 hoses.
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.
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.
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.
Usually has an 800 frame roll of film.
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 the test
These can also use the TruVelo system or the inductive loop system.
Mobile Gatso Cameras, Mobile Installation Post (MIP)
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 roadwork's.
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.
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.
Readings can be taken in a fraction of a second. It needs a flat 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 the road.
Popular in Kent, Manchester 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.
LTI 20-20 and Pro-Laser are both popular laser guns with the Police.
Now old technology, 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. Ku band 13.45GHz. However police now prefer Laser devices.
Suitable devices can help to foil speedtraps much to the dismay of the Police, radar detectors such as the Bel 550, Bel 966, Bel 330, Snooper 715, Snooper 815, Snooper S5 or Interceptor can all detect a Gatso camera when it is operational. Most radar detectors also include a laser detector for the mobile speedtraps.
For even more coverage for speedtraps people are also turning to GPS type speedtrap detectors such as the Cheetah C550, Road Angel, Road Angel Plus, Snooper Sapphire, Origin b2, Road pilot and Micro Road Pilot, these can give more reliable results and can pick up SPECS and Truvelo which a standard radar and laser detector cannot.
Some people will even turn to a grey area of the law in laser jammers such as the Target LRC100 and the Snooper SLD920x.
There are some products which seem to accidentally jam laser guns. Some of these are parking sensors like the Laser Pro Park and some will activate an garage door opener or a security light like the LT400. But the manufacturers of these products have made the products switch off after a short period, if they detects they are interfering with another device.
Some speedtrap detectors have GPRS built in as well as using GPS to detect their location. They use the GPRS mobile phone network to download speedtrap locations to their internal database, checking every 2 minutes to make sure the database is up to date.