How Speed Cameras Work

Many of us dread the sight of a speed camera, and even though they have not bee around for very long we still like to complain about them.
Many of us want to know if speed cameras are accurate, how useful they are and if we should trust them.

Not a lot of us are aware of how speed or safety camera works, but this article should enlighten you. You will also learn a little about the history of speed cameras too so you’re even more familiar with them.

Also known as a traffic enforcement camera, speed cameras date back to 1905. That was the year that a patent for the ‘Time recording camera for trapping motorists’ was filed.

The principle behind this road traffic camera was almost the same as the principles behind today’s cameras. The camera would take 2 photographs of a car as it moved between the start and the end points of a certain part of the road.

However, we are not sure exactly what triggered the camera.

There were other attempts made to come up with a camera over the next 60+ years. One of the most ‘Famous’ types of cameras developed was the Gatsometer.

The Gatsometer

The Gatsometer was created to help a rally driver by the name of Maurice Gatsonides to improve his driving. The Gatso camera was eventually used as the first enforcement system.

In fact, this type of camera is made by the world’s biggest produces or cameras. The very first cameras were introduced in the 1960s and they were used to record an image.

They continued to be used until the 1990s. Digital speed cameras were used from then on to catch those who exceed the speed limit.

These days, cameras can be divided into 3 different groups depending on how they are all used. These groups are fixed speed cameras, average speed cameras and mobile systems.

If we want to divide the types of speed cameras based on their technology we can divide them into specs cameras, laser and truvelo cameras.

Mobile Speeding Cameras

These types of cameras are usually found on police vehicles. They are also known as “Radars” and may be mounted on a vehicle, on a tripod, or they may even be hand held.

Finally, this type of camera may also be concealed, which means it will be placed where you least expect it to be.
Cameras such as this have their own detection equipment. This allows the carrier to record the speed of motorists. This is irrespective of whether the carrier is moving or stationary

This type of camera also has the ability to detect speeds when the carrier is moving against or with the traffic.

Using laser technology, cameras such as these emit a beam of light towards a vehicle. The light takes between 0.3 and 0.7 seconds to determine the vehicle speed. It also has a range of 800 metres.

When a target has been locked it sends out a beam at a specific frequency and a specific angle. When a car enters the beam’s field the radar technology is reflected and the frequency of the beam changes.

The frequency changes thanks to the motion between the vehicle and the radar. The degree of the frequency and whether it has increased or decreased depends entirely on the speed of the vehicle.

Cameras such as these can detect whether the vehicle is rear facing or forward facing. We already know that the frequency of the beam can change and is used to understand how fast a car is travelling.

As the beams are directed at a 20 degree angle compared to the road, a shift in frequency will show a speed. This speed is usually slower than the vehicle’s actual speed.

The radar will then calculate the angle and work out how fast the vehicle was moving.

Fixed Speed Cameras

A camera that’s sat on the side of UK roads is known as a “Fixed camera”. These can be mounted on or near traffic lights or bridges.

Cameras such as these detect a vehicle’s speed by using Piezo electronic detectors. These are wires that have been added to the surface of the road.

When a car travels over one detector a signal will activate the camera. If the vehicle’s speed is higher than the speed limit a picture will be taken of it.

The speed will be determined by the amount of time that it takes for the vehicle to reach another set of wires.

Cameras such as these make a note of the time, date, location, speed, direction of travel, and the speed limit on the road. It also makes a note of the lane that the vehicle was in.

Cameras such as these can scan multiple lanes and are able to pick up offending vehicles from a line of traffic. If you have been caught speeding by one of these cameras it’s likely you will need to pay a speeding fine.

Average Speed Cameras

One of the most simple types of cameras out there is the average speed camera. Police forces like to use these cameras that are otherwise known as automatic number plate recognition cameras.

Cameras such as these do not use radar technology they just use photographs and a bit of mathematics. When a camera knows the distance between points A and B in addition to the time that your vehicle departed point A it can determine how fast you were travelling.

Also known as Specs cameras and used on smart motorways and regular motorways these cameras can pick up your number plate relatively easy.

While knowing how speed cameras work can make you more familiar with them it will not help you beat them. If you want to beat the speed camera the only thing you can do is drive within the speed limit.