Safe Speed Forums

I don't see anything wrong with that, the measurement will have completed by then (or some of timings of the latter pulses were rightly rejected).
The width of the beam at 190m should be about 60cm, about the width of the plate on the car.

Even if it was going at the same speed, it still proves my point, that the bounce off other cars is irrelevant. It's very unlikely he'll be going any slower.


Sorry no! I know exactly what these things actually do and I can tell you they don't work like that, trust me - I've actually tried it! Samples timings outside of the expected 40cm window are rejected; in this case that jump is many, many meters. More than 5 rejections will void the speed measurement. Even if the mirror did get in the way, the measurement will fail due to the colossal change of reflection coefficient.


I can't see how you can conclude that. The silver car being in the same axis of sight as the red one, in a closer lane, means it will pan across the video much quicker, even when both are going at equal speeds. Your latest post below is invalid for the same reason.


There is a clean line of sight to the reg plate for the 0.33 seconds needed to acquire the speed (ignoring the fact the gun can reject some samples).


Strictly speaking, it is proven that the car cannot have achieved that speed during the time of the test (just like the disclaimer on an MOT certificate). You should realise that other external influences can factor in here.


As irrelevant as this is: No-one can ever assume speedo overread. I recently drove an old car where the speedo greatly underread (displayed 25 at a true GPS confirmed 30).

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Views expressed are personal opinions and are not necessarily shared by the Safe Speed campaign

wrong the 4 other cars are traveling in the inside lane, closer than the target vehicle so the focal field may give the impression of a faster speed, the operator is correctly tracking the said vehicle waiting for the opportuinity for a clean shot




is the artist formaly known as smeggy agreeing

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now retired

Some interesting points here.
But, after all the analysis of the video etc and going back to basics, it seems to me that the owner of the car doesn't appear to be quite so stupid as to go to all those lengths to prove his innocence if he actually was doing 98mph........

Some might say it could be worth it to some to avoid the obligatory court appearance and heavy fine (98 is above threshold for basic £60 and 3 points). Many have done worse whilst risking far heavier penalties, some actually copping jail time.

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Views expressed are personal opinions and are not necessarily shared by the Safe Speed campaign

[edit remove post - changed my mind]

I suppose the point I am maaking is this. If the laser gun is being used correctly, then why has it produced a reading that is impossible. As proved by testing the car, which showed it wasn't possible to acheive the speed indicated.

http://www.dailymail.co.uk/news/article ... andal.html

A very interesting article on the innaccuracies and total mis-use of laser guns.

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My views do not represent Safespeed but those of a driver who has driven for 39 yrs, in all conditions, at all times of the day & night on every type of road and covered well over a million miles, so knows a bit about what makes for safety on the road,what is really dangerous and needs to be observed when driving and quite frankly, the speedo is way down on my list of things to observe to negotiate Britain's roads safely, but I don't expect some fool who sits behind a desk all day to appreciate that.

It isn't impossible for that speed reading to have been correct; IMVO opinion it is more likely that it was correct.


That's incorrect due to the series of bad assumptions within that statement. As I've already said (and I will expand upon):
it is proven that the car cannot have achieved that speed during the time of the test. Just like the disclaimer on an MOT pass certificate, the results of that test has no provable relevance on the LTI hit due to other highly significant factors such as:
- potential modifications to the vehicle between the time of the LTI hit and the track test (it was resold and potentially cosmetically modified within that time period)
- the terrain (advantageous at the location of the LTI hit)
- the weather (wind could have given it a sustained boost a the time/location of the LTI hit)

Also, I see nothing wrong with how the LTI was used at the time of the hit (although I accept it was possibly out of alignment, but any alignment error would have to be huge instead of minor, examination of the entire session video could confirm the [in]accuracy of alignment). As CamOp said, the outcome of the case could have been substantially different if the LTI operator had attended.


I realise this isn’t what some people want to hear from me, but I’m not going to keep silent simply because I’m swimming against the tide of opinion. Should I ban myself for dissent?
I know and can prove the LTI can give erroneous readings, but I sincerely believe those who rely upon this flimsy case as proof of the flaws of the LTI risk damaging the credibility of the real solid arguments.

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Views expressed are personal opinions and are not necessarily shared by the Safe Speed campaign

Why do I suddenly feel dirty

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Views expressed are personal opinions and are not necessarily shared by the Safe Speed campaign

So, Steve, what are your opinions of the Daily Mail article, posted above?

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My views do not represent Safespeed but those of a driver who has driven for 39 yrs, in all conditions, at all times of the day & night on every type of road and covered well over a million miles, so knows a bit about what makes for safety on the road,what is really dangerous and needs to be observed when driving and quite frankly, the speedo is way down on my list of things to observe to negotiate Britain's roads safely, but I don't expect some fool who sits behind a desk all day to appreciate that.

I remember this one. The measurements described within were real examples of slip error (although the description of one of the tests was misleading).
Unfortunately the [ self-moderated] Frank Garrett answered this with false claims of his own ('can get slip from a stationary object but not from a moving one' - a great paradox).

Like I said, I know the LTI is flawed (from real personal experience - the easy way I might add [never ever been caught speeding]).
See here (wayback page might take a while to load) for a classic technical ping-pong between me and the infamous Steve Callahan (CSCP).

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Views expressed are personal opinions and are not necessarily shared by the Safe Speed campaign

That car should do that in 3rd, mine err, might .

If he was doing 98, those cars that nipped in front of him must have been going very fast to not cause him to brake, which would have been seen by his front end dipping down sharply.

I didn't see anyone indicating to change into L3.
No car nipped in front of the alleged offender. The road in question is a 3 lane carriageway (A38, Plymouth); the other traffic you see is in lane 2 - the road bends right at that point (otherwise the camera operator would have to be standing in lane 2 and will be run over); traffic seemingly changing lane is merely an illusion.

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Views expressed are personal opinions and are not necessarily shared by the Safe Speed campaign

Whatever the truth you have to admire his balls.

This beggars belief!!!

Well done to the lad for his endeavours, but did the CPS/Magistrates not challenge the evidence, especially as the expert was not appointed by the court as a Single Joint Expert?

It seems that all you have to do is get a ticket at these sorts of speeds, adjust your throttle plate, sent to expert who will say it cant go "that" fast.

I don't know what top-speed Honda say it should do (I guess about 105mph), but with some basic data this can be calculated without need for test driving! Was the gradient of the actual road factored into the tests?

Of course I don't know the full details of the case, but on the media reports I have seen, I am surprised that the CPS/Magistrates accepted this at face value. If I was advising a prosecution, I would say, why doesn't it do 98mph now?

And anyone with an electronic limiter has a gift - reset the limited to whatever you want, say 85mph, and when your expert says "didn't you realise that the limiter kicks in early at 85mph", you say "how would I know, I never go above 70mph".

Expect some Court Guidance to be hurried out to stop this potential "loop-hole", just as in the Hamilton Case.

dont you start

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now retired

[quote="camera operator

dont you start[/quote]
Who me? lol

Actually I reckon this lad is smarter than we may think!

Wasn't it convienient that his friend owned it between the "speeding" and test? Suppose CPS discovered evidence that the throttle had been adjusted, and recently? Well his friend would say "Oh yes, I had a fiddle with it and didn't realise I had messed up". Not the Defendant's fault and his friend hasn't done anything "wrong" either - an excellent Plan B if ever there was one. And of course his friend would have said he had a fiddle because "it didn't seem to go as fast as I thought it should". Very smart folk in Bristol it would seem.

However the above is purely speculative and I am sure the defendant was innocent.

In Australia we have had a few well publicised cases where people have been able to prove that their vehicle could not possibly do the speed claimed by the prosecution. Unfortunately, as is apparent in this case, the prosecutions were carried out in spite of the facts and it was only publicity pressures that made them withdraw. All cases involved fixed speed cameras which operate without a secondary measurement system. One flash and you are ash!

In Sydney Government buses were alleged to be going up a fairly steep hill at 80+ kph in a 60 kph zone. As these are governed to 80 kph and struggle up this hill at 50 kph and the drivers know the position of the camera it should have been obvious to the authorities that there was a problem. Unfortunately it took a threatened strike, which would have deprived Sydney of its bus fleet, before the prosecutions were withdrawn. It was postulated that the error was caused by shockwaves from the heavy vehicle affecting the measurement system which was either piezo-quartz or magnetic induction looping.

In Victoria a Datsun 120Y driver was charged with driving at 150 kph in a 100 kph zone. It took one of our tabloid style "Current affairs" TV programs to demonstrate that this car (and others that they borrowed) could not reach more than 120 kph. The Datsun 120Y was a 1970s 1.2 litre shopping trolley with a fastback body and was as slow as a tortoise when new.

Another Victorian case was a semi (Semi-trailer=articulated heavy goods vehicle usually 1 steered axle, 2 driven axles and 3 trailer axles for 22 road wheels max mass 42 tonnes) accused of 170 kph. Again not physically possible even if the driver (who is usually the owner) had tampered with the compulsory speed limiter (set at a nominal 100 kph with a +5 kph leeway). Again it took the tabloid media (who for once put aside their "Speeding truckies should be hung, drawn and quartered" attitude) to convince the authorities to withdraw.

Our Magistrates, who are all stipendiary, are notoriously difficult to convince that there is a fault in the prosecution of motoring offences so public ridicule is a good tool to use in defending really silly cases.

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The only thing that should be prohibited is prohibition.

Reports said the cps withdrew because the operator could not appear so "offered no evidence" this is a different story to the rather more newsworthy "my car won't go that fast" tale. I reckon that might be what this is as performance some time later is not really material. Am I wrong in thinking 98 is no problem for this Honda normally?

Well possibly, but I have been in a similar circumstance to this myself. I had an extremely strong defence against the charge that I was alleged to have commited, and would almost certainly have won the case. In my case also, the CPS offered no evidence because the charging officer could not appear. My barrister at the time said it was common when a case was un-winnable for the CPS to offer no evidence, something to do with the reporting of crimes etc.
I of course don't know if that is what happened here, but it is a possiblity. To be able to report that the case was lost due to a failure to appear looks better than losing the case?

One thing does bother me with this, surely it would have been far cheaper to simply locate two landmarks in the video, and go to the road and physically measure the distance. Then using the video get a time that the distance was covered, then you can calculate speed. I still believe that the result would have shown that the car was not doing the speed alleged, but we'll never know now.

How can you believe that? Surely there is nothing concrete to base this belief on? There are at least three different types of factors at play; at least one of them is advantageous to the defendant beyond any doubt.

Is it still your belief that:
- 'that there is never a clean line of sight to the car'?
- the 'silver car is clearly going faster than the subject car'?
- the 'speed reading is the speed plus the distance between the 2 cars'?
- the '3 are clearly going faster than the target car'?

Granted your own win might have a resemblance to this case, but surely not at the technical level we’ve been discussing?

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Views expressed are personal opinions and are not necessarily shared by the Safe Speed campaign