Speed Detection Devices In Scotland

Fixed Cameras

The two most common fixed cameras are the GATSO and the SPECS 3. There are other devices but we shall focus on these two.

GATSO

The GATSO (or Gatsometer) is a type-approved camera device. This means that Parliament is satisfied it can be used for enforcement purposes to the extent that evidence relative to it can simply be given in certificate form unless such certification is challenged by the defence. It measures speed by using radar technology.

How does it work?

The GATSO tends to be sited at the side of the road. In the past it used induction loops laid into the road. Most models now use radar. In Scotland they tend to be set so that they can only “observe” one side of the road.

The GATSO takes  photographs of the back of the vehicle, the purpose being to identify the vehicle. Digital technology take the picture. A computer than accesses registered keeper detail. The driver is identified by a process called the section 172 procedure which, by law, must be complied with:

Source: Road Traffic Act 1988, section 172

Radar technology inside the camera is used to measure the speed of the vehicle . A second photo is taken 0.5 seconds later. During that time, your car will have passed over a certain amount of lines on the road which are meant to be a set distance apart. A basic speed/distance/time equation is then carried out and the resultant speed is meant to provide the essential corroboration to the first speed taken by the radar technology.

The GATSO is not unbeatable. We have more success in beating the GATSO than almost any other speed detection device.

SPECS 3

The SPECS 3 is a type-approved device. This means that Parliament is satisfied that the cameras can be used for enforcement purposes to the extent that evidence relative to it can simply be given in certificate form unless such certification is challenged by the defence. Photo use is governed by strict statutory rules:

Source: Road Traffic (Offenders) Act 1988, section 20

How does it work?

SPECS 3 system uses video cameras at two locations to record vehicle registration plates. Each time a camera reads a plate it electronically ‘stamps’ the image (not visibly) with times taken from two independent clocks which is a requirement of Home Office Type Approval. The Primary Clock is derived the Global Positioning Satellite system (GPS). SPECS 3 system also has another independent, free-running Secondary Clock that is meant to be periodically synchronised to the Primary Clock. This time is also stamped electronically to each number plate read. The latter is meant to provide the basis of the secondary check and it is this area which may prove problematic for the Crown.

LASER TECHNOLOGY

The most common laser guns used in Scottish speeding cases today are the Unipar r SL700 and the LTI 20.20 Ultralyte 1000.

What is the Unipar SL700?

The Unipar SL700 is a laser speed measuring device. The Unipar is designed and marketed by Unipar Services of Tunbridge Wells in Kent. It is marketed as “one of the most compact and advanced units available in the world”. According to Unipar , it has an effective range of between 10m and 700m when “hand held”. It is a battery powered device, using 2 “C” cell batteries which provide up to 50 hours operation.

How does it work?

Typically, the SL700 is operated by the operator holding the device in their hand, secured by a wrap-round strap.

An operator looks through a heads-up display mounted on the top of the device. The operator sees a “red dot” and targets this red dot on the vehicle then pulls the trigger to obtain a speed recording. The gun emits a series of pulses in rapid sequence. It does not ACTUALLY measure speed. Rather it measures the time taken for the “pulses” to travel to a vehicle and – after bouncing off the vehicle – back again. Because the speed of light is fixed, the gun is also able to work out the distance to the target vehicle. The gun then basically carries out a speed = distance/time calculation to work out speed.

The gun can be used in daylight or at night and in all weather conditions. It can record vehicles travelling towards or away from the operator. It is a “type-approved” device which basically means that the Home Office believes that it can be relied upon to produce accurate speed readings. The Unipar SL700 is marketed as being accurate to +/- 1mph/2kph.

Potential weaknesses

Many judges, police officers and prosecutors choose to believe that the Unipar SL700 is infallible, notwithstanding even the manufacturer concedes it can be inaccurate up to 2kph. But all technology has its limits and laser technology is no exception.

It is possible to aim the device at a static surface such as a wall or a road and convince the machine that the surface is moving at speed. This is because the device is not directly measuring speed but actually carrying out a speed/distance/time equation. If the dot is moved over a surface, a speed will  be recorded because of the “extra” distance the dot has travelled. This means that accidental movement of the gun, perhaps due to hasty targeting, can lead to an error called “slippage”. Slippage can occur if the laser beam hits the wrong part of the car such as the bonnet and “slips”.

Police witnesses sometimes use phrases such as “pinpoint accuracy using a red dot targeting system”. This is misleading. The beam expands over distance (as an analogy, think about the way the beam of a torch expands over distance).  The beam can be metres wide by the time it reaches the car. This can, mean that an incorrect part of the car (such as the bonnet) can be struck.

These arguments require skill, experience, tenacity and perhaps a more detailed knowledge of the gun than the police officers themselves have. Not are all of these arguments applicable in every case. The reason that we continue to beat the Unipar SL700 on a regular basis is that we recognise when there is the potential for an error and are ready to capitalise.

THE LTI 20.20 AND CONCEPT 2 VIDEO RECORDER

What is the LTI 20.20?

The LTI 20 20 (or to give it its full name “LTI 20 20 Ultralyte 1000”) is a laser speed detection device. It can be used on its own or, as in your case, with camera equipment known as the Concept 2. The gun has two lens on the front panel. The top lens send out an invisible light beam to a target vehicle and the bottom lens receives signals back from the target vehicle. It is a type-approved device which means that Parliament is satisfied that the gun can be used for enforcement purposes to the extent that evidence relative to it can simply be given in certificate form unless such certification is challenged by the defence.

How does it work?

The LTI 20 20 is mounted on a tripod at the rear of a camera van. It is hooked up to the Concept 2 situated to its side. An operator looks through a heads-up display mounted on the top of the device. The operator sees a “red dot”, targets this red dot on the vehicle and pulls the trigger to obtain a speed recording. The gun works in basically the same way as the Unipar. On the video screen, the red dot is replaced by cross hairs which are meant to indicate where the red dot is striking the car. The gun can be used in daylight or at night and in all weather conditions. It can record vehicles travelling towards or away from the operator. It is a “type-approved” device. The LTI 20.20 Ultralyte 1000 is marketed as being accurate to +/- 1mph/2kph.

What is the Concept 2?

The Concept 2 is the video attachment to the LTI 20 20. It is hooked up to the gun and everything that the gun “sees” is recorded in real time onto a data card. The data from the card is then transferred onto a DVD or Blu-ray disc to be viewed and used in court. Stills from the image will also be taken.

FLAWS IN THE LTI 20 20

As with the Unipar SL700, many judges, police officers and prosecutors choose to believe that laser technology is infallible, notwithstanding even the manufacturer concedes it can be inaccurate up to 2kph. But all technology has its limits and laser technology is no exception. The LTI 20.20, as a laser device, has the same inherent flaws as the Unipar SL700.

One big advantage of the video evidence provided by the Concept 2 is that the usage of the device can be subjected to closer scrutiny than is possible with the Unipar SL700.

IN-CAR SPEED DETECTION DEVICES IN SCOTLAND

The two most common in-car speed detection devices in Scotland are the calibrated speedometer and the VASCAR device.

Calibrated Speedometer

Speeding cases based on calibrated speedometers are less common than laser or camera cases but they do happen. A typical example is:

• A driver overtakes a police car.
• The officers within the car form the impression that the driver is breaking the speed limit and pursue them.
• The police are then meant to take up a position behind the suspect and track his speed. This is done by keeping a steady distance between the police car and the suspect’s car.
• So long as a set distance is maintained, it is possible to infer that the speed showing on the police speedometer is the same as the speed of the suspect’s car.
• The minimum distance over which the speed should be recorded is 0.2 miles.
• Various defences are available to an accused driver in these circumstances. They will usually involve whether a set distance has been maintThe police claim that calibrated speedometers are accurate to +/- 2%. This, however, completely ignores the “human factor. ained and/or whether the Crown can prove the accuracy of the police speedometer.

VASCAR

VASCAR is a speed detection device in Scotland that works on the well-known principle of speed=distance/time. It is essentially an on-board computer fitted to most road traffic patrol cars and is accompanied by a video screen.

VASCAR can be used in various ways. The most common is known as the “follow”. This is similar to the techique used with calibrated speedometers. However the police car does not require to maintain a set distance behind the suspect’s car. Instead the following technique is used:

• The police wait until the driver passes a suitable “marker” such as an overbridge or a change in the road surface.
• They then push a “time” button on the device.
• When the police car passes the same marker, they push a “distance” button. #When the suspect’s car passes a second marker the police stop the “time”.
• The device now knows how long it has taken that car to travel between the two markers.
• When the police pass the second marker, they stop the “distance” measurement. The device now knows the distance between the two markers. It does a speed=distance/time calculation to obtain an average speed.

Beating VASCAR

There are other methods of using the VASCAR but this is the most common. A very high degree of operator accuracy is required.  The speed returned is only as accurate as the timings with which the buttons are pressed. The visibility of the markers, the experience/training of the officers, the distance travelled and the distance between the police car and the suspect car are all crucial elements in a case involving VASCAR. Before the Crown even gets to that stage it must first be proved that the VASCAR is accurate which is far from straightforward. As with other devices used to detect Speeding in Scotland, we have an exceptional track record in defending cases using VASCAR technology.