To provide evidence in an allegation of speeding the police can use many different types of speed measuring devices, as well as the old fashioned method of following a vehicle down a road in a police car. These are used to measure the speed of a driver to provide evidence for a prosecution. The types of devices which can be used include Gatsometers (the classic speed camera), VASCAR in car systems, automatic number plate recognition systems that are used to calculate the average speed of vehicles and a system of road tripped devices known as Truvelo. 

It is an inherent requirement in any prosecution to prove that any speed detection method is properly placed and calibrated. The officers using any equipment must also be properly trained in its operation. The prosecution must be able to demonstrate that when, where and how the machines were used are in accordance with specific rules. Without this proof the prosecution may fail to prove a speeding offence.

1.92 million speeding tickets were issued in 2005 (the last year for which data is available) with the majority of offences being dealt with under the fixed penalty scheme. Motorists are increasingly accepting a speeding conviction without ever seeing the evidence against them, or allowing a Court to test this.