I've just been stopped for speeding in a 30mph zone. Now before you all start on about there being no excuse for this the road is very wide, large 8ft wall runs the whole length down one side and is nowhere near any residential areas. The policeman jumped out from behind a tree like a salmon and zapped me. Now when I looked at my speedo it was reading 35mph or possibly just under so I braked and thought that there was no way he was going to pull me over for that speed. He did of course and informed me that I was actually travelling at 42mph! I informed him that my speedo was reading about 35mph but he said his speed gun was correct and my speedo was probably mis-reading.
I asked him for the calibration certificate which he couldn't provide and told me it was probably down at the station. As I don't know the area I asked if I would be able to look at the certificate or a copy at my local police station which he said they may be able to fax a copy.
My question is that if they cannot provide a calibration certificate what should my next move be.
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Hello Marcos
The speedtrap bible website is well worth a look for this it has loads of detail and examples of where calibration has not been proved and the consequences for Plod.
as ever
Mark
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Its simple.No certification of calibration or any evidence that it has been correctly calibrated would render the coppers evidence as unreliable,therefore by by prosecution.
I would suggest that if you want to go this way plead not guilty,ask for all the statements etc and then at trial ask the copper as to what evidence he had that the gun was accurate at the time you were caught.It may also if applicable to find out if they are a competant person to use such a precise measuring device.After all the law provides such people in the shape of Trading Standards Officers who are authorised to enforce the Weights and Measures Act.It does not authorise coppers.
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>>The policeman jumped out from behind a tree like a salmon
I've never seen a salmon leaping out from behind a tree before. Must be quite a sight. ;-)
Getting back to the point, is a correctly calibrated speedo part of the MOT? If it is and your MOT is recent then you could use that in your defence.
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Wally, speedo calibration isn't part of a car's MoT. However, all vehicles fitted with a tachograph are required by law to have it calibrated on a yearly (I think) basis.
>>The policeman jumped out from behind a tree like a salmon
Marcos, isn't there something in law now that a mobile speed camera sight must be adaquately advertised? I know that whenever the police have set up a site around here, there is a sign warning you. Generally, it's resting on the back bumper of the camera van, but it's there nonetheless. I thought that the days of policemen jumping out from behind hedges, trees and the like were long gone. In fact, I'm 99% sure that this practice is no longer allowed. I'm sure that m'learned friends can help here. Over to you, DVD...;-)
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Check your speedo just in case. As a quick check drive on the motorway and use the 0.1Km markers if there is nobody about travel at 30 mph and time the distance between 10 markers should take 1 min 12 seconds. Use a GPS on a straitish section or find a mate with a standard car with standard tyres and do a quick 20, 30, 40 ,50, 60 comparison. Sory to hear that Regards Peter
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Perhaps the 8ft wall was creating a doppler effect which was causing the radar receiver to give a spurious/incorrect reading. It has been known. Anyway shouldn't the calibration certificate be kept with the equipment?
VD5D
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>Perhaps the 8ft wall was creating a doppler effect
The doppler effect is the change in frequency of a *moving* object.
In fact its the doppler effect that measures the speed.
Now I know lots of people hit objects that leap out in front of them, but i suspect the wall was not moving........
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Don't speed cameras have to be fixed in some way? There is no way to hold them perfectly still, and if he did take a reading before he had a chance to stabilise the device then any reading could be possible. For these devices, I'd suspect correct use will make more of a difference than calibration.
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>Don't speed cameras have to be fixed in some way?
Radar? Nope can be used hand held quite easily.
>For these devices, I'd suspect correct use will make more of a difference than calibration.
As has been pointed out, no calibration certificate, not allowed as evidence even if its 100% accurate or not.
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As has been previously mentioned the operator needs to be competent to use the equipment. Also the physical conditions in which the equipment is operated must meet Home Office regulations and consideration must be given to not obtaining erroneous readings from background objects.
Chapter and verse can be found on either of the 2 speedtrap sites and links can be found in the speedcamera threads as I recall.
as ever
Mark
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The gun measures the relative vcelocity of car and gun using the afore mentioned doppler effect. It the copper lept from behind the tree towards you the gun would overestimate the speed and it he lept away from you it would underestimate the speed. Either way a moving gun can not be reliably used to measure the speed of the vehicle relative to the ground over which it is moving in a single measuement.
Stands back and waits to be corected or informed that the gun measures the velocity of the copper with respect to the ground and the angle between the car's velocity and the copper's velocity and the velocity of the car.
Wish I had paid more attention in A level applied maths now.
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You admitted speeding, which may have been 35 in a 30. Plod say you did 42.
Would it make an ounce of difference to your conviction if it was 35 or 42, I dont think it would. So why are you bothering to question the speed.
Note I was caught doing 42 at 4 am on a sunday on a deserted road, it makes no odds whatsoever when/where you were caught.
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Puntoo
The problem here is the fact that someone doing 30mph is still going to get nicked so the police can fill their coffers.
If I am going to get stopped for speeding I would like some definate proof that the speed on the radar gun was the speed my car was actually going or something is obviously very wrong with the law.
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Marcos you have admitted to seeing the policeman jump out, then you braked and looked down. All of which would take a few seconds.
How about you are travelling very near to 40, someone jumps out, so you move your foot from gas to brake (which slows the car down a little), you then look down (maybe you had started to break by this point) and see the speed which is now 35. Seeing as your speedo can be anything upto 10% out either way (or so I have heard), you would only have to be travelling at 38-39 mph to get a reading of 42.
Viola. 3 points on the board and a fifty quid fine.
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No. I looked down and saw my speed was fairly low so didn't bother to brake as I didn't think i'd get stopped.
I've done this a hundred times when i've spotted a speed gun and I know when i'm going too fast and yes I was breaking the law so I deserve the points and fine but what I'm annoyed about is the speed he recorded which I think is excessive.
P.S. My speedo can't be far out as it always reads either the same or 1mph out from my GPS system.
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Puntoo,
While it's marginal, 35 is the sort of area where you might just get away with it, not to mention that speedos often read high, so a displayed 35 might only actually be 32.
Does the amount over actually affect the penalty though? (Other than I gather you get a ban if you go more than 2x limit)
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AIUI
Speedos _must_ either over-read, or be correct.
Never under-read.
Unless any else knows better :-)
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Speedos _must_ either over-read, or be correct.
By design, yes. Running larger wheels, or potentially high pressures (although this would have far less of an effect) would alter their reading.
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If _you\'ve_ made your speedo wrong whose problem is that?
A poor point to argue with in a court..
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Steve
are you suggesting that its ok to travel at 35 (on your speedo) because there is a good chance that your speedo is wrong and also a good change that you will get away with it ?
Why not travel at the 30 on your speedo (or get your speedo correctly calibrated)
It shows that the 10% + 3mph unoffical limit for speeding just encourages people to tavel at the highest speed they can get away, then complain when they are caught, rather than being a safety cushion for incorrect speedo's.
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TBH, Puntoo, if everyone did drive at limit+10%+2mph then there would be far less of a speeding problem.
However, that's not what I meant. 35 is usually considered the 'upper limit' of what you can get away with. Also, at worst your speedo will show the actual speed, it will *never* show a lower speed than you are doing (if your car is in standard spec) and will often show high as a safety margin.
IMO, 35 is too fast unless you are on one of those daft stretches of road that is a 30 for no conceivable reason, and even then should someone decide to apply the limit then tough. However, 35, especially with a measurement method that has potential for not being massively accurate, is a very dodgy call.
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Steve
how can you be sure that the speedo will never be lower than the speed you are doing. I am no expert on speedo but it would be down to manufacturing tolerances/problems, and I dont see how they could ensure it one way or the other.
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Simply because that is the way they are designed and calibrated. The thinking being that it's safe to let you think you are going faster than you actually are, but not vice-versa.
The only case when a speedo will read low is if you have fitted over-sized tyres to the car. If you think about it, they know the tyre size, can work out the maximum circumference based on a fairly high tyre pressure, they measure the wheel speed (or more likely somewhere earlier in the drivechain) so they can set the speedo to read based on these 'worst-case' figures.
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>The gun measures the relative vcelocity of car and gun using the afore mentioned doppler effect.
YUP marks out of 10 - 10
>It the copper lept from behind the tree towards you the gun would overestimate the speed
Errr so thats the gun a foot nearer?
>and it he lept away from you it would underestimate the speed.
And that would be a foot further away?
and in that time - let me see - the car (at 35mph) has moved?
17.11 yards in one second? (if my maths is right but it seems a long way i admit)
so thats +/- 1 feet added to 17.11 yards? Not a big margin i suggest
>Either way a moving gun can not be reliably used to measure the speed of the vehicle relative to the ground over which it is moving in a *single measuement.*
Doesent, it takes lots and uses an average
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By my calcs:
14 and two thirds yards in a second.
But doesn't alter the principle you describe.
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Got to go back to my days with the HR8 hand held and perhaps MLC can advise what is being done now.
Firstly the HR8 had Home Office approval i.e. that it would do the job intended with accuracy and to get this approval had been subject to stringent testing.
So off we went on an opeartion. Firstly test of the patrol car speedo against stop watch/ measured mile to prove accuracy. Site for op chosen then patrol car ran through the gun at set speeds to prove it was working OK. End of session similar exercise and at times during the op used tuning fork which was programmed to vibrate to produce a known speed reading on the gun. IIRC certificate of this calibration was held at Court Office for production if the need should arise. Final check of speed of patrol car as at start. Any variation or defect discovered then all previous op speeders not processed.
Now I have heard various theories that the beam bounces off glass, telegraph poles, wheel rims, radio signals, but in all honesty I never came across this at all.
As to signs, never used them and did not resort to hiding , no need, because in full view they came at you like salmons leaping a weir.
DVD
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>It the copper lept from behind the tree towards you the gun would overestimate the speed
Errr so thats the gun a foot nearer?
>and it he lept away from you it would underestimate the speed.
And that would be a foot further away?
so thats +/- 1 feet added to 17.11 yards? Not a big margin i suggest
Says Renault Family.
You seem not to be able to understand the diference between speed and distance. If the copper lept forward like a salmon then perhaps he would be moving at about 35 MPH [based on olympic sprinter] - thus if at the time he was taking a measurement it would be significantly in error. We would not expect a leaping copper/salmon to keep this up for long - but perhaps long enough to take the measurement. {about 2 micro seconds} Its not how far he lept whilst he was using the gun its how fast he was leaping that counts.
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I would have thought it more likely most of his leap would be at rightangles to the oncomming traffic, making little difference to the measured speed.
Also in doing that he would _not_ be using the gun as taught?
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Just been reading the "ACPO code of practise for the operational use of road policing enforcement technology"
Very complete and full volume on how and where and with what you can be nabbed speeding.
Well Marcos, your salmon copper would have had to leap out from behind his tree, and quote "stand at the side of the road facing the oncoming traffic" "have a clear unobstructed view of the road" and "once a reading has appeared on the display the radar device should be held steady pointing along the road for a duration of no less than three seconds. During this period a steady reading must be obtained which equates to the observation of the operator"
Now this little lot takes a while to perform, in full view of the target motorist....................
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Most hand helds these days are Pro-Laser, which DO NOT need to be held for three seconds. They give an instant readout. The calibration certificate does not need to be kept with the device (although ours are). It should be available at the station where the device is stored. My Force is pretty hot on recalibration, and keeps meticulous records of where and when.
The device is checked against our patrol cars calibrated speedo before and after use.
My views on the targeting of your average motorist are pretty well known by now. I'm afraid it's only to get much worse.
MLC
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Was the device Pro Laser or was it radar? Did the salmon show you the display? Did it show the average speed and the distance travelled during the check? Did you not receive a FPT for the alledged offence?
I would suggest "the salmon" had recorded and locked your speed on the device before he perfomed his leap.
"I've done this a hundred times when i've spotted a speed gun and I know when i'm going too fast...." Make a habit of this do we???? Can you tell the difference between 30 and 40 without a speedo?
At the end of the day the principle of whichever device was being used is that it is corroboration for an initial opinion of excess speed.
There is plenty of advice and opinion on the site and the internet so I shall not say any more other than like DVD I have never found any readings that were suspect with either device.
DVD. Could never hit that note on the tuning fork though!!!!!!
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Full Chat
I actually own a radar detector but I don't bother using it anymore because I don't drive fast on minor roads anymore, apparently it's something to do with hitting 30yrs old, so basically I will only use it when travelling through France and Spain.
I know when I'm speeding and I can assure you that if I thought I was travelling above 40 then fair enough but I certainly wasn't and wouldn't in a 30 limit. I do enough driving to be able to tell the difference between 30 and 40 and as for you saying that you have never found any suspect readings on these machines I can assure you that these machines are forever going out of calibration which is why they are checked on a daily basis.
My argument is that when I go to site and do various checks and then write a report I have to supply copies of all the calibration certificates and if I don't then all my testing is a waste of time. Why if I have to do this with my job can't the Police? Or are they really a law unto themselves.
Marcos
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Marcos
The ACPO Manual of Guidance states that the machines should be calibrated on a regular basis. Calibration certificates are of course issued and depending on local policy as to location are filed until required. The device also carries a small calibration sticker giving dates. Also all operators of the equipment should also be trained. I carry an authority however it is not a requirement that I produce it.
I asked wether the device was Radar or Pro-Laser. The Pro Laser runs through a series of self-tests. If any do not come up to scratch the device will not function. In addition although not obligatory is a 'run through' at a specified speed on a calibrated speedometer which is also checked over a measured 1/2 mile/mile against a calibrated stopwatch. This is done before and after use. Belt and braces and shows that everything should stand scrutiny.
The later generation Radar devices do almost the same and again they are checked by an independent device ( the speedometer) before and after use.
The Police are not a law unto themselves. All the equipment is calibrated but they are not obliged to carry or show any certification. However if the matter were to go to court then all records of calibration and validation could be requested.
I maybe should have been more specific. When I said that I had not had any suspect readings I meant during speed checks. Any problems had been discovered during the pre checks and the device faulted.
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The leaping salmon is actually a red herring (or maybe a brown kipper) cos the salmon is going to say he didn't leap at all and there ain't nowt your going to be able to do to prove otherwise. The gun should be calibrated however and if it isn't you'll be having poached salmon for tea.
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