Driving on a road exceeding the prescribed speed limit
If you are doing more than 30mph over limit you are very likely to be disqualified depending on the speed of your vehicle, road traffic conditions, weather etc.
If you are offered a fixed penalty option, and you are guilty then you are probably best to take this option, as your licence will be endorsed with the minimum number of penalty points and the fine (currently £60) is likely to be less than that imposed by the court. There will also be no court fees.
Possible defences are that you were not speeding, that it was not you driving, or that you were driving an exempted vehicle in an emergency.
The prosecution may obtain a conviction by producing in evidence photographs taken from speed cameras. There is no requirement that such photographs have any other evidence to back them up. If no photo is available then the evidence to convict you must come from at least two different sources, although one of these may be mechanical such as the police car's speedometer / radar gun / VASCAR.
Under s20 of the Road Traffic Offenders Act (as amended by s23 of the Road Traffic Act 1991) where a radar device is used the police merely need to provide a record produced by the prescribed device AND (in a same or a separate document) a certificate as to the circumstances in which the record was produced, signed by constable or authorised person.
