Here are some basic facts about speeding that you probably didn't know, but ought to!
There are just two basic types of speed detection equipment used in the UK:
- The first group can only perform a single, instantaneous speed measurement. Two examples of such devices are radar and laser guns. Take a look at our links page for more information on these devices.
- The use of the above devices isn't allowed in moving vehicles in the UK, so the police have to use "time and distance devices". The distance over which they measure your speed is governed either by the Constabulary's procedures or operational practicalities and not the law. Such devices produce an average speed and they're all manually operated, so there's room for human error - this is where we can help you.
There are other types of "time and distance devices" used that are not in moving vehicles - such as the "double flash" speed camera.
You're guilty of speeding once you travel at 1 mph above the posted speed limit - or even less if they can measure the speed! For this reason it's referred to as an "absolute offence". The amount over the limit you need to be or the minimum distance over which your speed has to be measured is down to the procedures of individual Constabularies and not the law.
The police only use speed-measurement equipment to reduce paper work and court time, and to reduce the likelihood of the defendant arguing about the evidence. Under the law you could be convicted of speeding based on the "expert opinion" of a couple of police officers on bicycles armed with nothing more than note books. As you can imagine, this method would cause all sorts of arguments in court and slow down the "administration of justice". Magistrates could still convict you under the law and use either their, or the police officer's, "expert opinion" to decide the speed.
As we've already said speeding is an "absolute offence", and this means that unless you can prove that you were not speeding you'll always be found guilty. Obviously in the vast majority of cases, you won't be able to prove that you weren't "speeding", and if it's your word against a police officer's the Magistrates will almost certainly take the officer's word. A speeding offence does not offer the defendant the option of having their case heard in front of a jury at a Crown Court. Even if you appeal you don't get a jury - take a look at what happened at the appeal in our case file number 4.
So speeding offences don't attract many of the rights associated with other more serious offences. If you're accused of a more serious motoring offence, for example dangerous driving, you can opt to have your case heard by a jury at a Crown Court. This story on the BBC News website shows how ordinary members of the public can get in the way of the "administration of justice"!
So remember, speeding is an "absolute offence" that these days attracts large fines, that you'll never be able to opt to have your case heard by a jury of your fellow citizens, and that the law doesn't mention evidence, traffic videos, speed measurement equipment, ACPO guidelines etc.
Most of the relevant law was written a long time ago; for example the precedent for one police officer using the speed of the police vehicle to measure your speed was set in 1931. The basic premise on which the the law is based is that the police officer's "expert opinion" of excess speed is enough to convict you of "speeding", and any equipment that's used to measure your speed is merely to corroborate that opinion. Point 12, (c) in this section of the ACPO guidelines will help you to understand why a patrol car's speedometer can be used to corroborate the opinion of one officer, and this section explains how the speedometer should be used when performing a "follow check".
As speeding is an absolute offence, the law doesn't distinguish between a motorist who's driving at 71 mph or 171 mph - the variable punishments that are suggested in "Magistrates Guidelines" are not part of the law.
If there's no speed-measurement equipment at all then there must be two police officers; the second has to corroborate the opinion of the first as to the "excess speed". Obviously in these circumstances deciding the "speed" for the punishment will be the problem, and that's why most Constabularies use speed measurement equipment these days. However, now that we have variable punishments the "speed" has become very important; for example if you look at the Magistrates' Guidelines, you'll see that driving at 91 mph in a 70 mph limit is potentially far more serious than 90 mph, and this is why it's so important that you take the time to study the evidence and to ensure that it is accurate!