Everyone wants to know how to beat a speeding ticket, red light camera, or breathalyzer test but how many actually believe they are innocent? Regardless your motive, the common denominator is that you have a legal right under the United States Constitution to provide a valid defense for the alleged violation. I am sure some [...]
Everyone wants to know how to beat a speeding ticket, red light camera, or breathalyzer test but how many actually believe they are innocent? Regardless your motive, the common denominator is that you have a legal right under the United States Constitution to provide a valid defense for the alleged violation. I am sure some of you are asking, “What does this have to do with technology or security?” and my response is, EVERYTHING!
The Inside Scoop
On January 7th, 2010 I was pulled over by a Lakeland Police Officer who allegedly clocked me going 64MPH in a 40MPH zone. I had just turned right at a red light and pulled up next to a truck when he was pointing the laser radar gun (lidar) in my direction. I didn’t believe I was speeding but decided to not speak up since it was my word against a machines. Amazed at the alleged speed, I elected to go to court rather then pay the $264 for something that I believed to be inaccurate. This is when it all started…
The Crossroads
My arraignment was set for February 11th and the Hearing Officer (Judge) opened up with a statement explaining the State of Florida presumes that any electronic device used for measuring speed is considered accurate and operating correctly if the operator provides proof of training, the radar gun has it’s 6 month certification, and the radar gun log with the date in question on it. This left me in a very awkward state; Do I pursue my innocence or just suck it up and get railroaded? Of course I plead ‘Not Guilty’ and made an ad-hoc request to the Hearing Officer/Judge. My request was for the release of the source-code used by the radar gun in question. My prior research before court showed that the LTI 20/20 Radar Gun has had a well researched case in its inaccuracy. The source-code was ordered to be released and they pushed back the court date to give the State of Florida ample time to request and deliver.
- The Great Speed Gun Scandal
- Laser-Based Speed Camera Fails Accuracy Test
- BBC Documents Errors in US Laser Speed Guns
- UK Court Finds Long-Range Speed Camera Inaccurate
- BBC Inside Out – Mobile Speed Cameras
A Sticky Situation
If the State of Florida relies on a device to bring charges, infractions, or fines then its only legal that the same device should considered for a competent defense for the Defendant ensuring the rights under the Florida and United States Constitution. If the device source-code is withheld then what defense does the Defendant have? What will the source code tell us? If it is withheld, what is it hiding besides trade-secrets? Where will closed-source devices used by Government agencies lead our civil rights since the use of technology is growing more and more everyday? Will non-disclosure of source-code open up Pandora’s box for anyone cited or charged where an electronic device was used to determine guilt? I don’t know, but I can tell you that my motive is not to try to save the world.
Dooms Day
My non-jury trial is scheduled for April 8th and I have yet to receive any source-code. Today I filed a ‘Motion to Compel Radar Gun Source Code’ hopefully to enforce the release of the source-code so I can accurately defend myself. The problem now is that court is in 2 weeks and I haven’t even started to dissect the source code.
Technological Barriers
In almost all cases of traffic infractions, the use of some sort of mystical device, whether it be a radar gun or a red light camera, is used to determine someones guilt. The court usually presumes the device to be accurate if it is tested and approved through a specific set of tests inside of a controlled environment. This makes it difficult, if not impossible, to accurately defend your innocence because of the pre-conceived notion by the Judge or Hearing Officer that the device is true in its findings. What if a defendant wanted to review the source-code to the device, would it be made available for inspection? What about validating that the firmware on the device is the same firmware that was calibrated and certified during the Federal approval process? What I am getting to here is that there are major barriers restricting valid attempts of defense when facing a loss of driving privileges, financial penalties, and potential incarceration. This makes for complete closed-source devices and opposes the recent “Open Government Directive” instituted by our President. Looks like its moving towards a major violation of our Civil Rights.
The Proof is in the Footage
(Sorry for the quality, its all I could get from BBC)
- 1 min 34 secs – 2 min 34 secs – Explanation of the ‘slip effect’
- 3 min 54 secs – 4 min 55 secs – False Results
UPDATED: 03/09/2010
Wow, what an exhausting trial. The officer and I went head to head for awhile discussing the inconsistencies in the lidar gun. I shown actual pictures of a LTI 20/20 lidar gun being used in a higher speed capture due to a ‘Slip Effect’, ‘Reflection’, ‘Beam Spread’, and ‘Misalignment’.
The Judge and Officer argued that because traffic court is not under the same laws that govern criminal court, they have no obligation to provide evidence under ‘discovery’ to a defendant for defense. The Judge also refused to enforce her previous order from arraignment for disclosure of source code stating that the Florida law requirements of what has to be shown (i.e. device certification, daily logs, and trainer certification) has been met by the Officer. She also argued that since it was intellectual property of a company she would not compel the State. The Officer admitted to using the device from inside the vehicle without a tripod even though he agreed the manufacturer recommended alignment with a tripod, the NHSTA required certification on a tripod, and the State of Florida requires calibration on a tripod.
Another thing they refused to take into consideration was the amount of time it would have taken me to cross the laser beams path from where I had taken my right hand turn at the red light. The approximate distance confirmed by the officer was .2/mile. To travel .2/mile at 64 MPH would mean I would have had to been going 28.61 Meters Per Second making total travel time 11 seconds. This is assuming there is no traffic but keep in mind I was behind a black truck up until I switched lanes just a few seconds before I crossed the .2/mile mark and was clocked.
The officer did make some good statements regarding my defense. First, he questioned the dates on the pictures that I shown stating that technology changes drastically in 4 years. This is very true, my rebuttal was that without seeing the source code there was no way to tell if and what changes occurred therefore we would have to assume that these LTI 20/20 devices are still flawed. His next bullet was that the pictures show a LTI 20/20 Marksman and not a Ultralyte. Once again, very true and very good statement. My rebuttal to this is that all LTI 20/20 devices are using the same codebase with different features. They are not going to provide a different speed calculation algorithm for different devices.
The Verdict
After we were finished tearing each other apart, the Judge ruled to deny my motion to dismiss and adjudicated me guilty using the previously used “Florida law requirements” as grounds for a guilty verdict. This is very interesting considering the State of Florida failed to comply with a court order, the proof that the LTI 20/20 devices are pron to miscalculated readings, the allotted time it would have taken me to cross the laser beam, and the device failing to comply with the governing the laser beam size requirements under Florida Statue 15B-2.016(2)(c).
The Conclusion
In most cases like this, the defendant would not even pursue challenging a laser radar (lidar) ticket. In the event they do, everyone including the Judge, assumes the defendant is guilty leaving the objective of the defense to prove innocence. The catch 22 is that the prosecution hides behind laws that restrict defendants from being able to prove a defense because all that is required for a guilty verdict is a few pieces of paper. Whats more alarming is that these pieces of paper (device certifications and training) do not take into account real world scenarios or the possibility of slip, beam spreading, or reflection. They get a stamp of approval which is the key to the court systems lock. How can this be a ‘right to fair trial’ and even more how does this satisfy the ‘rights of the accused’? They argue its not criminal but if it is not criminal, how is the court allowed to impose fines, fees, points on your license, suspend your license, or even sentence you to jail time?
My next step is to appeal the Judges verdict. A few people asked if I would be willing to appeal it and take it further. Some even said they would donate to help offset some of the fees. This is no longer about a speeding ticket, its bigger. Its now about your civil rights as a United States citizen. If you are willing to support me in any way, please send me an email: michael at iGlobalOnline dot com.
Slip Effect
Reflection
- Standing still car with a car passing
- Standing still car with a van passing
- Standing still car with a motorcycle passing
Beam Spread
Misalignment
* Pictures from A Review of Laser Speed Meters in Road Traffic Policing By: Paul D. Lee
I also brought forth a scientific report showing the actual laser divergence was 1/3 larger then the manufacturer reported. This is important because the Florida law states,
15B-2.016 Tests to Determine Accuracy of Laser Speed Measuring Devices.
(2)(c) – Sight Alignment/Beam Pattern Test.The sighting device will be checked for accuracy to determine that it remains within the laser beam at all distances from 500-3000 feet. This may be determined from calculation based on an initial beam pattern/sight alignment analysis. The beam will be analyzed to determine that it is within the pattern/size tolerances specified by the manufacturer.
Which means the certification of the actual gun should not have passed.
Divergence Calculations
Distance Claimed Laser Beam Width Actual Laser Beam Width
100 0.3 0.44
200 0.6 0.88
400 1.2 1.76
500 1.5 2.20
800 2.4 3.52
1000 3.0 4.40
Claimed divergence: 3.0 milli-radians
Actual divergence: 4.4 milli-radians
* Report Concerning Tests Performed at Elvington Aerodrome on 2 December 2006, by Dr. Michael Clark, dated 6 January 2007.
23 Responses
Win or lose, your insistence on ensuring that the blackbox is held to account is laudable.
Thanks.. Hopefully it might shine some light on the necessity for future transparency.
Can you confirm which model of LTI was used to determine your speed and what is the version of software the device was loaded with?
In the UK, the software in question has much greater error-trapping characteristics, the software being a different version to that used in the states.
What this means, is that there are different variants of software being used by police forces in different countries.
You cite Dr Clark’s work in this field, however he is in the UK and could not obtain a current model of LTI being used by any British constabulary and had to make do with an American model, one that wasn’t loaded with the same error-trapping software demanded by stringent British type approval.
What has therefore transpired, is that his work has been seen in the UK as proving that LTI’s are highly questionable, when in fact the equipment he used to demonstrate the LTI’s shortcomings had American software loaded with sub-standard error-trapping characteristics.
The software version is ultimately important to determine as this has a huge bearing on how British people view the LTI’s accuracy.
@Carl did you not watch the entire documentary? There was a ststement taht the UK uses the same version of the LTi as NASA and NASA say they use the same version as the US police. The whole different version theory strikes me as an excuse for the UK police force to wriggle out of any possible accusations of faulty equipment.
I equally would like the continual use of ‘radar’ gun explained? The LTI 20.20 Speedscope uses laser, not doppler effect radar technology to determine velocity.
The LTI sends out an infra-red light pulse and measures how long it takes to come back. The speed of light is a known constant so the distance can be calculated. It then repeats the process and using the difference between the two readings and time interval between the two, it calculates the speed.
Is the use of ‘radar’ an American thing?
john; thanks for responding, but you completely misunderstand.
Unquestionably the hardware is identical, the UK uses the Ultralyte 100 and the 1000 Speedscope, and a even a few old TSM’s, but the software is different here in the UK to that used in the states.
Having used both US and UK software versions, they are as different as chalk and cheese. I have also attempted on many occasions to replicate the manifestations he claims and every time the speedscope throws up an error exactly as it should, returning no false reading.
Don’t be fooled, Clark has never even handled a UK speedscope, everything he claims is complete speculation.
What software version was loaded in the scope that detected Michael?
its the ultralyte model using the u.s. version software.
Hi Michael.
I sympathise with your predicament, I have witnessed all kinds of attempts to obtain various and assorted items of crucial information regarding individual cases. Usually this is either only released just prior to it going to court, or not at all.
As I outlined in my previous submission, in the UK we have an assortment of LTI models in use. This is down to which constabulary is using them and what the speedscope is linked to (camera partnership run speed enforcement scopes are connected to either a tape or DVD recorder and the older scopes aren’t digitally compatible).
I understand that this is all a highly charged and emotive subject. Many people will read this and disagree with the basic ideology of there being different software versions and that they can behave so differently, simply because they have built their strong views and beliefs on what Dr Clark claims.
I therefore have no wish for this to develop into a protracted slanging match with anyone who wishes to sharpen tree cutting paraphenalia.
Most UK constabularies publish calibration certificates on-line, meaning you can instantly identify the equipment in use on the day of the alleged offence. Do you have any clue precisely which US speedscope model you are citing and are requesting and which software version?
Incidentally, I stumbled upon the following some time ago and for those who haven’t seen it, it is extremely interesting reading;
http://www.teletrafficuk.com/pdf/scientific_report_lti.pdf
Interesting pdf – the counter argument appears to be that
1. During Dr Clarke’s test, the device was used incorrectly.
2. The errors rate demonstrated is skewed because in a fuller test the ‘good results’ would leave the erroneous ones less statistically significant.
3. The research was carried out in a bad way because it only sought to show conditions under which the device fails.
4. Dr Clarke has less scientific qualifications than the writer.
Point 1 is a good argument if we can be sure that the policemen using the device are extremely careful in their work. I remain a little unconvinced about that.
Point 2 is a good argument for devices in which inaccuracy can be tolerated- this is however not such a device. If it says you were driving 64MPH then you should have been driving 64MPH and that’s it.
Point 3 The point of the research was to show that laser guns are less trustworthy than previously thought – seems fair enough then, to conduct ones research in such manner. In the end a re-hash of point two (hiding the inaccuracy in a body of statistical evidence that shows the device works most of the time).
Point 4 seems slightly justified. There is indeed little information to be found about Dr Clarke.
Carl, the report is indeed very interesting.
However, all this technical discussion is rather moot.
If the UK version is susceptible to the same issues as the US (and I’m not assuming anything in this case) then the issue with this case is that there is no possible defense against the reading given by a device which the establishment assumes to be perfect in every practical sense.
Assumption of perfection is all very well if it is indeed perfect.
However, as we all know, such a device does not exist.
The are so many variables such as environmental conditions, busy traffic and with the slight movements of the operator.
If you are that one victim of a statistically (perhaps) unlikely misreading, then what is your defense?
Michael – given that you claim to have just turned, can it be demonstrated that the speed with which you are accused is impossible because of this, with the acceleration characteristics of your car?
We’re all behind you. My old mother has beaten similar circumstances in the UK… and WON. Good luck.
@carl, very good find regarding the dr clark rebuttals. its good to see a companies transparency when it comes to negative criticism however it doesnt negate the circumstance. now i have a stronger defense knowing lti’s take on the discrepancy.
@ralph, I thought about doing some calculations to show the court and i may still present that side as it would be important to have handy.
@consience, thx for the support!
Hi Michael;
Obviously, not your preferred outcome.
Having faced people in court, many who have sourced the cornerstones of their defence from the internet, without question, the biggest drawback with this, is that it is more often that not, completely flawed. It is usually out of date, or simply based upon misguided gossip.
With this in mind, I did at least attempt to get you to identify which LTI model detected your speed, quoting Mr Lee’s hopelessly outdated report will always fall short of what is required and can only really be supplied by an expert witness who is up to speed with current models and software versions.
One thing that potentially let your defence down (although I doubt anyone in court would have been aware), is the issue of beam divergence.
Although the beam does indeed diverge conically, it isn’t all active. If you can picture the metering pattern of a modern camera, the LTI’s laser is very similar in that it has stripes that focus the sent and received data. We have gone from three vertical stripes within the cone, to two horizontal and back to three again over the course of three different LTI models. Although the beam does indeed extend beyond the published 30cm at 100m, the published 30cm refers only to the active portion, the bit that extends further/wider plays no part whatsoever in the collection of data. So even if the edges of the laser contact another vehicle, a wall or whatever you like, only the area within the metering stripes are the bits that do the work.
I strongly recommend you don’t get too reliant on antiquated information that you cannot corroborate. Unless you can cite definitive tests using the Ultralyte model and loaded software version, then no-one will take you seriously regardless of what you personally believe about codebases.
Hope this helps clarify such an important issue.
Hey Carl,
Speaking of sources, I had to work with what I had. LTI wouldn’t provide me with any thing technical and even tried charging me for the manual. The police department refused to hand over any documentation. The court did not provide me with any of the evidence that was used to prosecute me until yesterday when they showed me case logs of checking in/out the lidar gun and trainer certifications. All of this was what led to the original order of disclosure of source code in which even the Judge refused to compel the State to comply with her order. Although the source code alone is not enough to determine an accurate defense, it is the cornerstone.
I appreciate your comment on the divergence but at the same time the size of the beam is what is addressed under Florida law. The issue is that Florida law states the beam must not exceed the thresholds specified by the manufacturer. The discrepancy here is not whether the beam is collecting data but rather if the size meets or exceeds what is disclosed by the manufacturer. The moment the beam extends outside this allotted parameter, it violates the requirements governing the use by a State agency.
I agree with your last statement. Becoming reliant on information that I can not back up by expert witnesses did leave me wide open for prosecutors. This does not negate the facts that some LTI 20-20 devices, regardless of codebases, do or previously had flaws causing or enabling invalid speed calculations. This brings home the necessity for transparency within the brains behind the device. Without out, its nothing more than fancy physics assumed to be accurate, protected from being proven otherwise, and relied on by U.S. judicial systems to railroad citizens while violating their civil rights.
-Michael
The LTI Ultralyte 100 and 1000 manuals are actually freely available to download, albeit from a UK source;
http://www.teletrafficuk.com/downloads.htm
As I said earlier, I have attended many speeding cases in court, but have yet to see anything that unequivocally challenges the robustness and accuracy of the LTI speedscope in the eyes of those who matter on the day. Whilst Clark/Lee may have sprinkled the seeds of doubt with their research, this is nowhere near enough to halt the system as it stands or whatever continent or country it operates in.
This may be of interest to you if you haven’t already seen it, you may find something of value hidden away whilst at the same time increasing your knowledge base;
Youhttp://www.motorcyclenews.com/MCN/News/newsresults/mcn/2007/February/week-06-feb5-feb11/feb0707camerabossadmitsflaw/?R=EPI-72976&content-block=1r Comments
Good luck.
Sorry, link above was wrong;
http://www.motorcyclenews.com/MCN/News/newsresults/mcn/2007/February/week-06-feb5-feb11/feb0707camerabossadmitsflaw/?R=EPI-72976&content-block=1
Apologies, faulty link above;
http://www.motorcyclenews.com/MCN/News/newsresults/mcn/2007/February/week-06-feb5-feb11/feb0707camerabossadmitsflaw/?R=EPI-72976&content-block=1
I’ve been accused of speeding twice 2 years ago and the speed readings resulted in one ban and the 2nd case after dismissing my legal representative Nick Freeman aka Mr Loophole was won in my favour, the courts accepted my version of events as I had a GPS tracker which could prove the speed. The CPS wouldnt let me have the software on the devices, so I pulled the PATENT and told them I was using this as part of my evidence. In the UK you have to tell the CPS what you plan to rely on evidence so they can build a case against it.
In the end the CPS moved the court on the day without telling me (as I was now respresenting myself) I guess in the hope of a conviction in my absence (sneaky and not becoming of the state imo) but I was on the ball and travelled from Kings Lynn to Swaffham where the case was held. I was not allowed to use any of the evidence I had compiled in my case as this would have blown this open globally as nearly all laser speed devices are made by a couple of US companies. The implication would cause problem for Insurance Companies and refunds of premiums and would also cause an admin headache for the refunding of fines and points here and elsewhere.
In the patent the manufacturers clearly state the devices are capable of getting speed readings from stationary objects, like armco barriers, vegetation and buildings.
Becuase the device is incapable of determining where the reflection has come from it, its incapable of determing the speed so an algorithm exists which takes the most consistent readings and uses that for speed but there is no way of telling where the device has got the reading from and its not enough to just have the device pointed in the general direction of the target vehicle especialy if the device operator is on the end of the road and you are travelling in the carriageway furthest away from the device operator.
The avg. length of a car in the 0.3 secs the device takes to send out the burst of (laser) light equates to + or – 30mph. Secondly if the device is used on the roadside then the speed readings will more likely get a reading from the side of the car or the surrounding environment like Armco Crash barriers or concrete central reservation barriers.
Theres two areas of doubt with these devices. Firstly there is nothing in the software for it to work out whether the reflection came from a car or its surrounding.
The device wont be accurate at all if the operator has to move the device to track the vehicle aka slip effect. These operators are not military trained long range snipers you know who undertake months and years of training in this art so it goes without saying there will be movement and panning errors. The most blatent errors cant be handled by the software on the device but these have to be very blatent.
Yes in the UK the software is modified but only to ignore readings obtained below a short distance so the courtroom trick of panning the device doesnt work any more as the UK has smaller courtrooms.
Finally if the state has nothing to hide then their reluctance to hand over their devices for independant inspection and analysis is a massive indicator that they are hiding. The already hide behind the acpo guidlines with magistrates choosing to accept the operators manual as part of the law when it suits and other times citing it as merely an operators manual and not law. The UK law is purposely grey here.
Anyway anyone can contact me for more info it will help blow the massive global coverup on these devices although it appears US law maybe a little more honest than UK law.
The device cant detect if you created the reflection As also mentioned on here I think, you have also noticed that beam divergence is greater than stated.
For Richard Rose;
You stated; ‘Yes in the UK the software is modified but only to ignore readings obtained below a short distance so the courtroom trick of panning the device doesnt work any more as the UK has smaller courtrooms.’
What exactly does this mean, what ‘courtroom trick’? Perhaps some specific distances too?
You also mention ‘…with magistrates choosing to accept the operators manual as part of the law when it suits and other times citing it as merely an operators manual and not law.’
Which specific legislation do you refer to in relation to the subject under discussion?
It is well known that Clark has demonstrated how the device can be made to create a speed when it is used in a way that a police officer would not use it. His results are not unexpected nor are they surprising.
This particular defendant in the USA should be made aware that the District of Columbia ordered that a number of cases, 9 I believe, should be heard together in a Frye (I think that is how you spell it) hearing. A number of laser guns and a number of independent experts examined and demonstrated the devices and examined the circumstances of all of the cases. The experts found that, during extensive tests carried out for the court, that no false or unexpected readings were created when the devices were used in their normal mode of operation. With no ill effects found or created all cases were found for the prosecution and the evidence from laser speed guns was found and ordered to be accepted in future cases.
Maybe the lady should be made aware of the compelling nature of the findings of the court of the District of Columbia and its appointed experts before money is wasted in a naive quest.
For Richard Rose
Evidence from drivers’ own GPS systems is not evidence that should be taken note of. It is not independent and is not verifiable for 2 reasons, 1. it is hardly reliable being from the defendant, 2. It is not time synchronised with the speedmeter when it is on the form of a document or recovered file so is irrelevant.
If your case was decided on this evidence you were very fortunate.
Shortcomings of the LTI 20-20 laser speed gun
By Dr Kalvis M. Jansons
The LTI 20-20 is a laser speed gun in common use by the police throughout the UK. It works by sending a stream of short infrared pulses from the gun to the target, and measuring the return times to determine distance. The rate of change of this distance is then interpreted as speed. Since not all parts of the target vehicle will be at the same distance, small movements of the gun can lead to erroneous speed measurements, as the rate of change of distance measurements is not entirely due to the motion of the vehicle. This is called the slip effect, and has been the subject of many reports, many of which feature Dr Michael Clark. The manufacturer and UK distributor of the LTI 20-20 boldly claim that the closed-source error trapping software will trap slip and other errors, provided the LTI 20-20 is correctly used by a trained police officer. However, Dr Clark’s observations make this claim look somewhat suspect, and the closed-source nature of the code means that professional scientists like myself cannot check the algorithms used. Furthermore, many scientists with whom I have discussed the LTI 20-20 agree with Dr Clark that the design concept of this device is fundamentally flawed.
Based on the LTI 20-20 UtralLyte 100 user manual, the acquisition time is less than 0.4 seconds, the range is 23 to 610 metres, and it can determine speeds from 0 to 299 mph with error less than 1 mph. It can measure the distance of the target within 0.1 metres and the beam divergence is 3 milliradians.
Many speed convictions are obtained by police officers not following the LTI 20-20 instruction manual. To avoid slip errors, the LTI 20-20 manual says that the target should be the number plate as this will be a good reflector of the infrared pulses and has the correct orientation. However, the LTI 20-20 is also used on approaching motorcycles, which do not have front number plates.
There are many other issues with its use on motorcycles that concern me. Motorcycles are generally much more irregular in shape than other vehicles, particularly from the front, and even more so if they are without fairing. The scope for slip in motorcycle speed measurements seems intuitively to be much greater than that for cars, but I am unaware of any research which quantifies this effect. In fact, I am unaware of any research that determines the rate of false positive errors for different vehicle classes. Furthermore, these rates of false positive errors should be determined for different distances and speeds, and the data made available to the public for use in court.
The manufacturer of the LTI 20-20 produced a report on the concerns of Dr Clark entitled:
Review, Analysis and Criticism of the Report by Michael A.G. Clark, Ph.D.: “Technical note: Unreliability of Laser Speed Meters” (Issue 1, Copyright 2005) prepared by Daniel Y. Gezari, Ph.D. and Chevy Chase, MD
This report is, in my opinion, a very unprofessional and unscientific attack on Dr Clark, and is filled with unsupported assumptions regarding the LTI 20-20, and what could be expected of a police officer using the LTI 20-20. It contains no new science to address Dr Clark’s concerns, and suggests that Dr Clark does not know how to do science, but that the author of the report does. If the report had attempted to address the issues in a more professional manner, I would have taken those points one by one and replied to them here. However, this report is not a useful basis for discussion.
Having read the report I was left wondering about the scientific background of the author. Most of the research of Dr Gezari is not, in fact, in a field directly applicable to the theory behind the LTI 20-20. However, some of his recent papers are, at least, concerned with laser measurements of the Earth-Moon distance. In his article “Lunar Laser Ranging Test of the Invariance of c”, he believes he has found “a first-order violation of local Lorentz invariance; the speed of light seems to depend on the motion of the observer after all, as in classical wave theory, which implies that a preferred reference frame exists for the propagation of light.” Any scientist reading this would have alarm bells ringing and maybe they would be hearing the music of “The Twilight Zone”. Roughly speaking, based on a very simple but erroneous calculation, Dr Gezari believed that he had overturned most of modern physics from Maxwell, Einstein, Hawking, etc. Most of us would probably think hard before publishing such a paper, and most likely assume that there was an error of some kind. What was his error? He forgot to correctly take account of the motion of the Earth and the Moon.
It is clearly true, as pointed out by Dr Gezari, that the working of the LTI 20-20 does not depend on special relativity, but it is noteworthy how Dr Gezari appears to deal with obvious errors in his scientific work. He seems to totally ignore them, and assume everyone else is wrong!
In my opinion, based on the report itself, and what I now know about the work of Dr Gezari, this report has no credibility, and almost no content. Furthermore, I also find it disturbing that Dr Gezari has served as an expert witness in a dozen court cases involving laser traffic speed measurements, and his report is used in UK courts.
Assuming that Dr Clark’s observations are correct, and they should be independently checked, I believe that the approval of the LTI 20-20 for use in the UK was initially a cock-up but the defence of it risks degenerating into a conspiracy. So much time and money has been invested in the use of the LTI 20-20 in the UK that in the short-term it is easier for all involved with its use to defend it rather than to review it properly in an open and scientific manner, and the report of Dr Gezari is just one part of this tangled web.
The fixed penalty fine system does not help either. Many people who know they have been wrongly charged for speeding using the LTI 20-20 will just pay up and take the points on their licence as the penalties can be so much larger if you go to court and fail to win your case. Most cases are won on the basis of incorrect use of the LTI 20-20, rather than on its flawed design concept and the erroneous false positive results that are likely to follow. A device like this should have never been approved without much more thorough testing with the results of those tests published in full and posted on the web for all to see.
Dr Clark appears to have demonstrated that the LTI 20-20 can be unreliable, so the use of the LTI 20-20, and similar devices based on laser distance measurements, needs to be urgently and thoroughly reviewed. Remember, that an erroneous speed measurement by such a device can put you in prison, or get you banned from driving, and several people have been clocked by the LTI 20-20 at speeds beyond the capability of their vehicles according to the vehicle manufacturers.
Many of the documents on which this comment is based can be found here:
http://www.benslow.org.uk/Speeding/index.html