Back when Seagulls were flocking, a small electronics company called LTI was in grave danger of going broke. They had but one product: a speed detection device (a.k.a. gun) that used laser light instead of radio waves. LTI’s laser gun was a $3500 item. Police agencies could outfit three patrol cars with state-of-the-art radar detection devices for that kind of money. Laser guns were DOA. And then the lizard people stepped in.
In a brilliant merger of public relations and greed, GEICO bailed out LTI. The insurance company bought LTI’s newfangled laser guns. In ceremonies held in each State nationwide, GEICO donated a few laser systems to the State Police or large local agencies. This produced many, many photos of a GEICO rep giving a high tech laser gun to the head of the local and/or State police agency in many, many newspapers in the many states where GEICO does business.
The handover was accompanied by the usual “speed kills” propaganda. As the nationwide 55mph speed limit was still the federal law, GEICO’s lazy-journalist press release got plenty of play. The PR stunt also put “free samples” of LTI’s laser guns into the hands of the agencies who would have never bought them in the first place. Once the cops gained operational experience with the new gadget, once the revenues started rolling in, laser guns became all the rage.
GEICO also banked big bucks with this initiative. The laser-wielding cops ticketed their policy holders. The resulting insurance surcharges more than paid for the cost of donating the laser guns. Brilliant! Well not entirely, on a whole range of levels.
Laser speed detection is an inherently problematic process. Calibration is the biggest “issue.” When police initially set up and/or test the accuracy of a given radar detection device, they use a tuning fork. This provides external verification that the radar unit is working properly. Police laser guns have no such external testing methodology. In fact, the laser guns use a proprietary algorithm to determine a vehicle’s speed. This they will NOT divulge in Court; apparently, it’s not patentable.
As strange as it sounds, a laser gun can only verify its own accuracy. Courts are not big fans of self-verifying devices, which is why Breathalyzers use an ampule of known alcohol for calibration. Even so, your legal guardians made an exception on your behalf. New Jersey uses other tests to allow a calibration “work around.” Most other states have either passed a law allowing laser readings, or just turn a blind eye to this possible objection.
Over time, police agencies acclimated to laser and made their legislative peace. The guns are now a part of most states' speed detection arsenal. And yet, laser hasn’t replaced radar, for one simple reason: laser is a bitch.
For one thing, laser doesn’t work on the move. Police have grown accustomed to using radar to monitor oncoming or distant traffic to detect and apprehend speeders in the course of other activities. There is no such thing as a patrol car-mounted laser gun; nor can there be, given the necessity of aiming a pinpoint beam of light.
This highlights another limitation: the laser gun’s laser beam must be shot directly at a car's front plate to create a valid reading. So cops can’t stuff their patrol car behind a bush, wait for a hapless/dangerous motorist to go by, and then hit them with a beam (the parallax error in this case underestimates speed). Police can fire the laser gun out of the window of a stationary cruiser, but that’s only in good weather. And anyway, then they’re sitting in a billboard labeled “POLICE.”
Accuracy is another stumbling block. Those of you familiar with handguns know how tough it is to group your shots. Laser is the same way. What’s more, most laser “shots” are initiated as far away from the target vehicle as possible. Most laser sightings are taken from around a thousand feet away (beyond that it is hard to get a reflection without a tripod mount). The beam is small; it’s quite easy to miss an offending vehicle, or, God forbid, mistake one for another. The majority of laser arrests need multiple shots before a reflection can be read, which is why a detector can sometimes save you.
Lastly, laser is also fallible. The guns only work on front plates. On states where front plates are not legally required, many motorists don’t have them (imagine that). Also, as it would be pretty hard to restrict a segment of the light spectrum for police use, most states allow laser jamming; devices which react to a weak laser signal by sending out a stronger one to trick or confuse the police gun.
In short, laser guns are highly effective when used properly, but standard issue radar guns will still be the police officer’s speed detection device of first resort.
This is an interesting series of articles. It is a topic I really knew nothing about, having been raised in the 70’s with the aformentioned shoe-box sized detectors that I was always told were really only another way of lightening your wallet.
Next, are you going into product reviews/recommendations? Because I could almost see getting one to share between car/motorcycle.
I’m glad laser is such a pain to use, because it’s also a pain to detect. The local police had a speed trap set up in a tunnel, they pointed the laser gun directly at either me or the person immediately in front of me or behind me (I’m not 100% sure who they were pointing at) and my Passport 8500×50 didn’t even make a sound. I have to think they were probably aiming at me as well, since my orange Corvette isn’t the most inconspicuous car on the road
Great article — lots of stuff I didn’t know, and I’m REALLY experienced at being clocked by every device known to man and state trooper.
BTW, I have used high-end radar detectors for years. I recently replaced a Passport 8500 with a 9500i. I mention this because I know when I get clocked with lidar, and I have had two or three lidar tickets. Yet I have never had a front license plate.
I assume from this that there are other parts of the car that can be used to reflect a laser beam if there is no front license plate, yes?
Laser doesn’t work on motorcycles because they are a small target, cops don’t even bother with them.
Excellent article. It’s somewhat comforting to know that the Laser has some drawbacks in regards to actual speed detection. I would be curious in seeing future articles and/or reviews on detection products. Keep up the good work!
Excellent article.
On vehicles without frontal license plates, the headlights are typically targeted instead. Large reflective surface. Chrome grillwork is also often a target. Rear-based shots work also (typically targeting the rear tag).
In either case, other areas of the vehicle WILL return a signal, just a less powerful, diminished one. Large, highly reflective vehicles (i.e. shiny, washed, white, large) are worse than dull, dirty, dark ones (i.e. small, black, dull, grimy, etc).
I credit my (now older) Escort 8500i with saving my butt from lidar on several occasions. That said, thetopdog is right, laser is a huge paint to detect. The laser has to actually hit the detector, to detect it hence positioning it properly makes all the difference. Depending on vehicle design, this may be more difficult and or more or less effective for some than for others.
A highly effective approach here is to “paint” your vehicle from static position on an overpass, from above and behind (where you’ll never see it and your detector is unlikely to pick it up), and then be pulled over shortly down the road by another waiting revenue collector. Motorcycle cop parked adjacent to and behind a bridge abutment/overpass column is also common.
Useful range is quite short, to get an accurate reading….under 500-700 feet is typical for final readings. At longer ranges (over 1000 feet) the beam dispersal is several feet wide, possibly picking up multiple or “wrong” vehicle(s), or too weak to generate a readable return.
Targeting is also difficult, for the reasons Mr. Raskob discusses, hence multiple shots are normally taken. There is no “locking” feature as on radar units, whatever is shot gives a return, so if the shot misses your vehicle and picks hits the one behind or in front of you, that is the reading returned.
Finally, rain, fog, and mist render lidar nearly useless, quickly reducing range and dispersing the beam.
Any angle between your direction of travel and the lidar unit aids you by reducing “read” speed due to paralax error, hence watch for lidar usage from directly in front or behind you…..even a few lanes off can be helpful (i.e. LE is in the median, while you are in the right hand lane).
This series, coupled with editorials by Brock Yates, has made me feel as if it’s the early ’70s and I’m reading C/D.
So what this article is saying is that if you get tagged for speeding with a lazer, all youhave to do in court is ask for external calibration verification and the case will get dropped?
@Casey – small quibble: what you call parallax error (I don’t agree with the tern parallax, but I’m not going to argue about that now) is also the same with RADAR. Both LIDAR and RADAR measure the speed of the car along the vector pointing from the car to the detector. So unless the cop is directly in front of you, they’re always reading a smaller speed.
@Cicero – any highly reflective surface that reflects back to the source, not off at another angle will work. License plates and the orange and red reflectors on your fenders are designed for that. A great way to see what parts of your car are the biggest LIDAR reflectors is to go out at night and take a picture of your car from far away with the flash on. The only parts of your car that will show up are the parts where the flash was reflected back to the source (camera). Try this from a couple of angles and you’ll see that the best place is your plate – that’s why they generally aim there.
Great stuff.
If I were still much of a speeder I would love this stuff. As it is, I am rarely on the highway anymore, and that is the only place I still speed. Limits are often set too low in the city, but a quick bit of math will tell you that you are not saving any time worth the hassle of being pulled over.
I wonder if something like Krylon Matte finish would help reduce the return?
Why do I suddenly want to BBQ a gekko?
@Landcrusher – Don’t know how much krylon matte would help. LIDAR is typically 1000-1500nm wavelength which is in the IR. Since that’s fairly close to the visible (400-700nm) chances are that the optical properties are similar. But you never really know unless you get an IR detector and see if it does attenuate the signal. The “best” solution would be to go all B2 stealth bomber and design the angles of the car such that any reflected EM radiation (RADAR and LIDAR) go off at angles away from the detector.
There was an article a few years ago about lasers being confused by driving lights. Anyone remember that one?
I seem to remember that the conclusion of the article was that you should have a large single light mounted centrally on the car, turned on during the day.
My old boss got out of a giant speeding ticket by requesting the radar calibration information, including the calibration of the tuning fork. Everything has to trace back to primary or physical standards. They’d been using the same tuning fork since the dawn of time and never checked it.
Great stuff, Casey!
Miked,
You cannot have a visibly altered license plate, or cover it. No matter how stealth you make your car, the plate is still there. You need a coating that won’t be obvious to the eye, but will reduce reflectivity or scatter the laser. You are likely correct about the matte finish, but something with tiny crystals or beads out of clear medium that you could spray on would work. Just needs to be tiny enough particles that they are hard to see.
Talked to a New York State Trooper while I was on a Thruway ambulance call and asked him where he aimed Lidar. “Right between the eyes,” he laughed. “I shoot for between the headlights.” Occurred to me that he’d ahve a hard time getting a reading off my 911, since all he’d hit would be a deeply sloped hood.
In the story it says laser guns can only hit the front plate for laser guns to work. This is 100% false. I live in the St. Louis area and I have seen for myself 2 cities and state shoot vehicles from the rear and pull them over for speeding. As long as there is a reflective surface for the gun to get a reading and the surface is not the side of a vehicle a correct speed can be obtained.
If in fact a laser beam hits the side of a vehicle or top of a vehicle it will cause an error or a errorus speed.
A good site to check out for further laser info is http://www.radardetector.net
I’m a trooper in Missouri and at first, I decided not to read this series. I expected the usual, “here’s how to beat a ticket” insipid foolishness. There are likely plenty of places to find that stuff. TTAC took the “high road” and just presented the information and let us, the reader go from there. I appreciate that.
I’ve been on the highway patrol for twelve years and have worked with both RADAR and LIDAR. As the series(and some comments) have pointed out, both devices have their pros and cons. Personally, I’d take RADAR all day long due to it’s mobility. Furthermore, our Stalker RADAR units allow you to check multiple vehicles speeds at once.
The parallex (sp) thing that somebody mentioned is known as the cosine effect and it always favors the violator. Back to LIDAR for a second. It is pretty slick for stationary work, and yes, over-passes seem to be the best place to check speeds. The color of the vehicle and the presence of a front plate do effect range. Shoot the target in the rear and run them down, if need be. Problem solved. It’s my understanding that the LIDAR device emmits numerous shots per second, thus the operator doesn’t have to.
Lastly, speaking only for myself, I can say that I’ve never targeted a specifically colored car, red, orange, black, etc…or type of car. It doesn’t matter to me. If you’ve got your foot in it on a regular basis, you’ll eventually get caught. Some of my highest speeds were written to people driving rather nondescript vehicles. Years ago, while assigned to St. Louis County, I stopped a guy in a 911 who gave me an earful. Apparently, I was picking on him because he was driving a red exotic–his words, not mine. Please.
DT
As per 1169’s post he is right to one point. Police seem to think that LIDAR guns have no errors. I am sorry to misinform them that they actually do. I am not trying to attack anyone especially 1169 personally but would like to bring to the attention that overpasses are not the best place to shoot cars. I myself as a citizen should be the first to complain. Reason being lidar guns trap most errors and report an error code if something goes wrong, BUT this is not always the case. There is such thing called a sweep/ slip effect. I wish that all troopers and police take the time to review the horrible problem with shooting too far from the side of the road or from an overpass. How the sweep effect or sometimes better known as the slip effect works is when the lidar beam is aimed on the side or the top of a vehicle (from an overpass) and reflects the pulse rate as traveling faster than it was because of the pulses sweeping a vehicle causing the gun to be confused. This effect will in fact cause a HIGHER speed than that of an actual speed. 1169 is right that MOST of the time COSINE errors do favor the driver but the SLIP EFFECT adds to speeds of up to 10+ mph.
I wish all lidar trained leo’s review the effect’s of the Slip effect. Reason being I know for a fact I was going 60 in a 60 because I am a laser and radar enthusiast and love to listen to the speed traps operate and where. Well one day a MSHP trooper targeted my car and did not get a speed until I was going under the overpass, at that point he got a speed and called out that I was going 81 mph. I know for a 100% fact that this was due to a slip effect because I kept watching my speedometer while he was shooting my car. He NEVER called out how fast I was going until I was going under the overpass. Lidar guns can get you at 3000ft away. Now why in the world would I go 81 mph in a 60 mph zone knowing that the trooper was shooting lidar on that overpass? Defiantly slip effect! If he had tracked my speed way out he would have called it out within the 300 – 800ft range which he did not.
For further info on slip effect you can check out – http://www.bbc.co.uk/insideout/southwest/series11/week1_speed_cameras.shtml
Or just search Google for “Slip Effect +Lidar +Laser” you will see that this is a problem and is not factored in because most leos think that lidar is 100% error free.
Here is the video for all the leo’s and troopers learn about slip effect.
http://www.speedcameras.org/video/insideoutvideo.htm
and the second one
http://youtube.com/watch?v=wTBXROqE9l8&
The effect can happen from an overpass as well as from the side as shown in the video. The LTI 20/20 is prone to the slip effect more than any other gun , however even with the error correction of other guns such as the Pro Laser III that the Missouri State Highway Patrol and Illinois State Highway Patrol uses are still prone to the problem of slip effect.
stlouisx50,
Thanks for the info, I’m always eager to learn more.
I can’t imagine this trooper was targeting your roof as you went under the overpass. But hey, I wasn’t there.
I can share my personal experience with LIDAR. It’s compact, but heavy. It’s expensive and I don’t own it. It was bought for the state with grant money. If I break it, I’m paying for a third of it…out of my own pocket. I know this because I had to buy the state a new tint meter that I lost. Anyway, typically I’d check the car’s speed and then GENTLY put the LIDAR down. Pick up the microphone. Relay vehicle speed, violator number, desription, lane checked, etc… to a waiting officer. The aforementioned process takes a few seconds, so that may be the delay you’ve noticed. As for your speed of sixty, opposed to the eighty-one mph reported. Who knows!! Again, I wasn’t there. Hope that doesn’t happen again though. It sucks to be falsely accused of anything.
DT
A twist on the concept behind the F-117A “Nighthawk” Stealth Fighter (and every stealth-capable plane that came afterward)…
If you have to have a front license plate, I wonder if you could scatter LIDAR by simply creating a convex bend or two in the plate. Maybe crease the plate horizontally, right down the middle, and bend the plate 5 or 10 degrees.
Would such an elimination of the perpendicular plane maybe have the effect of bouncing most of the light upward or downward and not back to the detector?
If that would work on the front plate, what would prevent it from happening on the rear plate?
Tilting the plate won’t work. Lidar will still pick up a reflection on the plate with it’s beam. The lidar gun does not pick up a straight line of laser rather it shoots bursts of light and looks for them in the receiving part of the gun.
If you ever get a chance to safely take a video camera and put it into night vision mode you will see how bright the light from the gun is. *Note this will only work at night time.
Also 1169. I wanted to thank you for being understanding and not being the type that like to trash others when they talk about your job. We need more on like you!
Many states buy license plates made with materials engineered to reflect as much light as possible back toward the light source. That’s probably the key reason they make such a good target.
Bending or tilting the plate won’t help.
However, I once read that tilting one’s radiator (the largest metal object in the front of one’s car) so as to deflect radar reflection away from the receiver might reduce the radar signature enough to give you an edge. I can’t recall if upwards or towards the ground was thought to give the best effect. Still, it seemed a little unlikely, as few radar shots are dead straight on and it seems to be effective, anyway.
And, a cursory glance inside my car suggested that tilting the radiator wouldn’t be easy.
LOL, police have got to laugh when the see people trying out of the ordinary tricks that have been myths for years. :) I know I’d enjoy it.
KixStart, you are right about the plates and why they are reflective. The reason that is publicized is so police can see them easier which is some of the reason but there are some others.
– lidar/laser reflection
– license plate readers
– more visibility to other drivers (well maybe)
1169hp, Reimbusing the state for 1/3 the cost of lost/stolen/damaged eqquipment? That bites. In private industry, I believe the practice of charging employees for such losses is illegal, unless they can demonstrate malfeasance.
You mentioned specifically a “tint meter.” Does this mean you actually check windows for maximum tint? Or is it for something else?
Kix, Your assumption on the “Tint Meter” is correct. Here is the law in Missouri Missouri Window Tint Law
Missouri Tint Law Enacted: 2002
HOW DARK CAN WINDOW TINT BE IN MISSOURI?
Darkness of tint is measured by Visible Light Transmission percentage (VLT%). In Missouri, this percentage refers to percentage of visible light allowed in through the combination of film and the window.
Windshield Non-reflective tint is allowed along the top of the windshield above the manufacturer’s AS-1 line.
Front Side Windows Must allow more than 35% of light in.
Back Side Windows Any darkness can be used.
Rear Window Any darkness can be used.
HOW REFLECTIVE CAN THE TINT BE IN MISSOURI?
Similar to sunglass lenses, some tinting film contain metallic elements that help in reflecting incoming light and reducing the glare and heat generated by visible light.
Front Side Windows Must not be more than 35% reflective.
Back Side Windows Must not be more than 35% reflective.
OTHER MISSOURI RULES AND REGULATIONS
Restricted Colors No colors of tint are explicitly banned.
Side Mirrors Dual side mirrors are required if back window is tinted.
Certificate Requirements Manufacturers of film do NOT need to certify the film they sell in the state.
Sticker Requirements No sticker to identify legal tinting is required.
Medical Exemption State allows medical exemptions for special tint. For more details about the specific terms of the exemption, consult your state law.
I will tell you they do check it ;) have heard of them checking them. I will say this is one good law that I agree with.
Kixstart,
The tint meter is for checking windows and stlouisx50 listed the MO tint law.
The darkest I’ve checked is 2%. In other words, only 2% of light was able to pass through the window. That’s dark!!!!
DT
Wow, 35%! I believe the limit in California is 10%. Basically no noticeable tint in the front windows. If your driving from Missouri to California in your car with tinted windows, beware. A guy here at work got busted fro not having a front license plate while driving through Texas from Ohio. He said that the officer didn’t seem to care that a front plate wasn’t required in the state that the car was registered in.
Lumbergh21, if your friend’s car was registered in Ohio he is required to have a front plate! Maybe that’s why the state cop busted him… he knew(?)