What is it and how does a fixed speed camera work?
The fixed speed cameras in Queensland operate using the same technology as the mobile speed cameras; Gatsometer (Type 24 AU). These fixed speed cameras currently operate in ‘Away’ mode, which means a speed is only acquired once you have driven past the camera.
Vehicles which exceed the speed cameras set speed threshold will be photographed. Once the film is processed the photographs are analyzed to ensure accuracy of the radar reading and a subsequent infringement notice is issued to the registered owner of the vehicle.
How is radar used to detect the speed of a vehicle?
A radar uses electromagnetic waves to detect objects and provide information about the distance and speed of a travelling vehicle. The radar sends radio waves (electromagnetic waves) at a given frequency and listens for their return (echo). If an object is in the beam, some waves will bounce off it and return to the radar. By dividing the time it took for the waves to travel back and forth by the speed of the waves (the speed of light) it is then easy to determine the distance.
To determine speed, radars use the doppler effect. They measure and scale the frequency variation between the radio wave sent and the radio wave received (echo). If the object is moving away, the frequency will be lower, if it is getting closer, the frequency will be higher. Depending on how much lower or higher the echo frequency is, it is possible to know at what speed the object is moving from the radar position.
Where are the fixed speed cameras located?Fixed speed cameras operating in South East Queensland are at the following locations:
- Bruce Highway at Burpengary
- Main Street at Kangaroo Point (approach to Story Bridge)
- Pacific Motorway (M1) at Tarragindi
Fixed speed cameras have been installed at these locations as they are difficult or unsafe to monitor by other enforcement methods that have a history of road crashes. Advisory signs are positioned 500 metres on approach to the fixed speed camera location.