Schneier on Security
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October 22, 2012
Camera Jammer that Protects Licence Plates
noPhoto reacts to a camera flash, and then jams the image with a bright light.
The website makes the point that this is legal, but that can't last.
Posted on October 22, 2012 at 7:18 AM
• 63 Comments
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They've been around for years - there was IIRC even a German company that had a patent on them.
In the UK, there are many speed cameras that do not flash. They just read the number with daylight or IR at night.
This product is not legal in New York City because Licence Plate Holders/Frames are not allowed on vehiciles in the city.
Plate frames aren't illegal in NYC (or NYS). Obscuring relevant letters/numbers is. Not sure how that would apply to this product, but it's not like the red light camera can pull you over.
I love the part about how they brag that their microprocessor "precisely times and fires the flash at the exact moment needed", as though there were a time other than "right now!". (One might imagine a counter-counter-measure with camera guys emitting dummy flashes, betting that the "noPhoto" widgets can't recharge fast enough. That would make a literally brilliant arms race though.)
The only reason to have one of these on your car is if you drive like an idiot (or are an actual idiot). There are so many ways to beat this thing it's not funny. IR, UV, take N photos in a row faster than the plate flasher can respond, etc. The fine should triple if you get caught using one, that will discourage their use or keep idiots off the road.
So: doesn't work in daylight or with cameras that don't flash. Doesn't work against paparazzi who use nonflashing camera. Produces really bright flash out of nowhere that will disorient the crap out of the driver immediately behind you. Perfect.
Not sure what kind of roads you drive on, but we have red light cameras on roads with 50mph speed limits. The drivers (not idiots) have very little time to decide what to do on yellow and the data seems to say that this is a problem.
Here's some links... http://www.motorists.org/red-light-cameras/...
Not sure if you'd get away with this in the UK. Obscuring your number-plate is an offence already.
I also remember a story why Watchdog I think into these products, and counter-flash were included. They police managed to post-process the picture enough to get a number plate.
If you want to break the law.. use James Bond style revolving number plates.
Many of the UK cameras (for example Truvelo fixed-cameras and the "SPECS" average-speed cameras) don't use visible flash - they're infra-red.
I'm told that a few infra-red LEDs fitted near to (or into the mounting-bolts of) the registration-plate and fed continuously with a suitable duty-cycle square-wave (to get high peak luminous intensity without exceeding the LED's average power dissipation) can be surprisingly effective.
No need for any special camera-sensing logic - just leave the IR illumination on all the time - nobody's going to notice.
I went to the site you posted about (http://www.motorists.org/red-light-cameras/studies) and noticed that this organization was also after money with the promise of "join us and we'll pay your ticket*"
Randy -- itsallaboutgettingmymoney
*Restrictions apply. See site for details.
My main objection to these cameras is that I can't face my accuser. If a mistake happens, then there's no way to win.
Randy -- technologyisperfect
The purpose of the red light and speed cameras is revenue.
Ask the bureaucrats what non-revenue generating methods they tried before putting in the cameras? Washington DC is the worst. I've read that some municipalities want to put in cameras to catch people that don't fully stop at stop signs.
Safety is the smoke screen, not the goal.
I assume red light cameras are calibrated and just flash once. The system has a potential to be a lot more complicated, though.
In general, digital cameras don't just have one flash. Back in the day, the way a camera measured proper exposure was to have a sensor that measured the light reflected off the film as it was being exposed, and would quench the flash accordingly. These days, digital sensors don't lend themselves to that (due to various reasons), and almost every digital camera with automatic flash exposure fires lower powered pre-flashes it uses to measure the needed exposure before opening the shutter and letting the real flash happen. This means that traditional optical "slave" flashes do not work with modern digital cameras unless the camera supports being set to completely manual "main flash only with no metering" mode.
Some cameras also use rapid pre-flash pulses to communicate with off-camera flashes prior to the actual taking of the picture.
There's also another aspect of red light running - short traffic lights' duty cycle. They're getting shorter - presumably for traffic optimization but some say it's for revenue optimization.
In my city there's a lot of dual-carriage roads with speed limits increased to 70 or even 80 km/h - but the yellow lights are really short. If you don't react within the very first second, you have to really slam on the brakes to stop before the intersection or slam the accelerator and hope for the best. Fortunately, red light cameras are not installed (yet) but there's always a risk of a stray police car.
My personal strategy is:
- observe the next lights in the distance and if they shine green for quite long already, be prepared and slow down a bit below the legal limit
- if caught on yellow at unawares, do a quick glance in the rear view mirror; if there's a truck or bus behind or someone "sitting on my tail" GO ON!
- otherwise, brake as needed, trying not to trigger ABS (maybe it's such in low-end cars only, but my experience is it performs very poorly on uneven pavements which is standard here by increasing stopping distance dramatically - I think I'm going to pull the circuit breaker on the little bastard one day).
Because we all know computers are flawless inventions that never make mistakes or are never intentionally programed to increase revenue by deliberately shortening yellow light wait times.
@Peter A. ref ABS well if you manage to brake just at the limit of the wheels locking (assuming even traction for all wheels) then you will be doing a better job than full-on brakes with ABS.
But very,very few people have that kind of feel and control for their vehicle (also the ABS system, unless venerably ancient, will control braking for each wheel separately, something that you physically cannot do)
So keep your ABS, it will help you immensely if you ever panic (one day you might) and when you are composed you can always excert your superior control.
Then on the red light cameras, I don't think we have any here in Finland, there is one intersection at the very center of the capital that has a speed camera that *might* double as red-light one but there the speed limit is 40km/h and the yellow is pretty long.
Anyway, the rule here is that you should stop on yellow but if it's not safe to do so (suddenly slamming the brakes will cause all sorts of mayhem behind you) go through (also in winter loss of traction when braking might mean it's better to "gun through" than hoping the car will stop before it's in the middle of the intersection). So if you get caught on red-light camera can't you just say "I considered it unsafe to stop" and what can they do ? Unless they can provide lots of timestamped photos proving you had ample time to stop and no-one was tailgating you anyway then it's your in-situ evaluation vs their photo that shows no context and has no knowledge of the surrounding circumstances (I do hope those photos are at least timestamped to the tenth/hundreth of a second from the light turning to red)
@Peter - no ALWAYS slam on the brakes. It's better to have the minivan/suv behind you brake, swerve and flip over than get points on your license.
Rear end collisions with airbags and head restraints are relatively safe and their insurance buys you a brand new car. If you have sufficiently evil lawyers it also buys you a boat.
@NobodySpecial - And if you live in one of those weirdo places where they get bizarre meteorological phenomena like rain or ice, presumably you should just curl up under the dash and accept your fate.
I need to design a tiny IR projector that projects a different plate number.
IR/UV strobe lights set to a different frdequency for each bolt hole. Preferably with filters over the UV LEDs to cut down on the visable light that the current generation puts out. ~60 Hz +/- 10-20% ought to futz the CCDs but good.
90-plus percent of red light camera tickets are issued for making a right turn on red without a complete stop. There are also many documented incidents of yellows being shortened on intersections after the cameras are installed.
Of corse if you had a small countries R&D budget you might program a computer to spot the cameras and zap em with a laser. Seeing as how strapping sharks to your cars roof is just a bit impractical. And they are so hard to train.
True story: in Albuquerque (NM, USA) they put in red-light cameras that take a picture that includes your front license plate and the driver.
problem being, in NM we don't have front license plates, just rear.
that was a few years ago, since repaired (i guess they took two photos, one front one rear) then later NM voters rejected the whole thing; couldn't find original fail story in three minutes on google.
The ABS in the 2007 VW is pretty good, even if you are on wet asphalt on the one side and wet steel on the other, It does not even pull you to either side. So would not want to miss or disable that one.
In Germany, they have a lot of speeding cameras like right before the city limits. So when you exit the city with 50 km/h, they want to make sure you do not accelerate to 100 km/h before exiting the city. This is sure making cash, but you would have to speed in order to get a ticket.
Red light cameras and short yellow sounds like creating rear end collision accidents on purpose …
I agree with you and the sad thing is, while they are promoting this as a 'safety' issue where offenders are fined. The flashes temporarily blind the rest of us. No bueno for millions of motorists that are already dangerous behind the wheel.
Safe? give me a break.
The Albuquerque story actually got better --
not only were the cameras poorly positioned, but:
1) The city signed a contract with the company providing the service for X years.
2) The local university did a study demonstrating that the presence of cameras increased the frequency and severity of the accidents at all but two intersections (it took them nearly a year and a half to act on that data).
3) The ticketing agency did not have the authority to issue tickets -- so they short circuited a couple parts of local law and ran into trouble with local criminal justice system.... eventually.
4) Class action law suits -- after cameras were installed, the city ignored the recommendations of highway engineers, and shrank yellow lights from 5 seconds to 3.1
FWIW Bruce, there's a lot of different plates down here now...
There's kind of "fisheye lens" ones that are only visible head on, otherwise they get exceptionally glarey -- and there's ones that are kind of like slats on a box fan -- similar to the above, if you're at much of an angle, you can just see the slats, not what's behind them.
People are right that these can't continue to last as lawful-- but fortunately, local politics is throwing them out as fast as they can when it came out that the government was literally trading lives for profit.
I live in New York State and often travel by car to Canada. When coming back into the U.S., cameras (with flash) take pictures of the front and back of your car as you approach the customs station (at least, they do at Niagara Falls). Presumably the customs officers can see those photographs at their workstation. If the license plate is obscured for whatever reason, that would give them justification for increased scrutiny, searches, and general hassle as you try to get back across the border.
There's a red-light camera near where I live, and for some reason every few days the lens gets covered with some sort of gooey crud that spoils all the pictures. It seems to be some mixture of dishwashing liquid, motor oil, lamp black, white glue and corn syrup.
.. I can't face my accuser
In Belgium, we got a ticket for €10 for having our fog lights on when it wasn't foggy; and who's really going to fight such a frivolous ticket. What's creepy is I had no clue where the camera was.
Obvious "speed traps" have caught my family as well, as it's impossible to go from 40mph-20mph instantaneously.
My father (who has high knowledge of radar) asked a cop what type of "gun" he was using for a speed trap and he was told "Sir, Do Not Question; ask at your court date." My dad says they are getting harder to jam.
Regarding red light cameras, my father also told me that on product testing, the other engineer he was with could zoom the camera (and did so right then and there) on an unsuspecting female driver's breasts, up to at least 1, maybe 2 miles.
I've ridden with a cop once, and I don't ever want to be told it's for my safety when I have avoided many accidents myself and felt like the officer was going to hit the curb or a power pole while he was typing on his in-car comp.
In Australia there are generally two photos taken (hence two flashes) to allow checking of false positives. Also plenty of cameras with IR flashes, though I'd expect this could be factored into such a product. I'm surprised there are not more red light cameras using video.
I don't advocate vandalism, but if you are going to do it, get it right: UV resistant spray epoxy and feathers.
To everyone who has noticed yellow lights getting shorter; I've noticed it here too in Washington State. Here's an altenrnative hypothosis: Suppose they start taking away peoples licences for repeated violations. It's a double win, greenies get more carpooling and, your local DOT gets fewer cars to accomidate. Bear in mind, that's just something to think about. Given that the Obama administration is completely cut off from reality, the truth might be even more screwed up than anything our reletively sane minds can come up with. Like space aliens in the UN telling people short yellow lights cut down on idling or some thing. Great prank if you want to mess with the humans, eh.
Baltimore had a great story where after an Orioles (major league baseball for those that don't know), the cops were directing traffic. However, the cameras stayed on........
I love that story.
If it's illegal to obscure your number plate, then it's equally illegal whether you do it physically or with a bright light. It might depend on the exact wording of the law, but that wouldn't be a difficult thing to fix.
The relevant law in NSW says:
"(b) the number - plate is not obscured, defaced or otherwise not legible"
so on a plain reading, I would bet that these are already illegal here.
Really? Traffic cameras are still relevant? I remember when they installed them in Utah back in the 90s. They only lasted a couple of years, because the entities using them mailed out the tickets, and were too cheap to use any sort of delivery confirmation. And since "the ticket must have gotten lost in the mail" is extremely plausible, nobody ever paid the tickets.
The issue here is not whether this device is legal, it's whether or not the technology they're designed to defeat is even viable. Unless you're taking pictures of the driver (as has been mentioned) assigning officers to hand-deliver the tickets and verify the photo, traffic cameras are useless. And since that's prohibitively expensive, it's not gonna happen.
Yay for security theatre!
I'd be in for a version that you put in a hat to obscure your face when people try to take your picture.
You put on your cursed +1 camera jammer hat --More--
The goblin wields an expensive camera --More--
You are blinded by your OWN flash! You stagger --More--
It hits! It hits! It hits! It hits! --More--
I'd be in for a version that you put in a hat...
Someone designed and manufactured a baseball cap that did exactly this for celebrities to ruin PAP photos.
The problem was PAPS might be knuckle draggers as far as the Celebs are concerned but some of them know their trade way way better than either the Celebs or the hat designers and worked out the hats failing fairly rapidly.
One such way around the hat is the cheap compacts with the Anti-redeye on that makes three or four flashes in quick succession to close the eye iris down. The flashes outstripped the hats ability to re-charge it's own flash circuit, another was to use large diameter lenses with much greater light gathering potential thus no need to use flash etc etc.
The relevant law in NSW says"(b) the number - plate is not obscured, defaced or otherwise not legible"
Oh dear that is baddly written law if the cameras being used ar IR or out of alignment with a normal drivers or observers position etc etc.
Because "obscured", "defaced" and "legible" are all "weasel words" due to their lack of precise definitions.
Even scientificaly they have little value, because any solid object that lets EM energy through at one frequency is going to block it at another, likewise reflective object surfaces are going to reflect differently at different frequencies. So if the camera in use has a narow spectral response you can pick diferent colours that reflect different spectrums to give different letters or numbers etc this latter technique is used to find people who are colour blind. I'm sure it would not be to difficult to find pigments that look nearly white and nearly black in say visable light but near uniformaly dark grey etc in IR and thus paint 13 in such a way that it looks like B etc.
The trick is to do such things without it being 'to obvious' such that even a lawyer with a smart mouth would have trouble convincing the appropriate parts of the judiciary that it was a "reasonable" thing to do.
The (supposed) real point at the end of the day is to find out why people drive at speeds considered excessive for the driving conditions or in otherways deamed potentialy dangerous when they reasonably should not unless they have a valid exception on any particular occasion.
Oh and arguably shortening the change times on trafic light sequences is a dangerous thing to do. Because at a junction to drive across safely you should be watching th junction not the lights because as some one once observed "lights don't crash into you, it's other drivers that do that"...
The problem with stuff that's technically legal is that court decisions on lower levels (where you'll end up first) tend to be pretty random (at least that's the case in Germany). If you want to be judged according to what's actually written in the law, you need to fight all the way up, which gets pretty expensive and takes quite a lot of time.
To make matters worse, obscuring the license plate on purpose is (IIRC) treated the same as using a fake one (or faking any type of government documents), which may well land you in prison (probably not on the first offense, but why take chances?). So you might just as well go whole hog and use a fake license plate with fake registration papers and everything. Same punishment, but lower chance of getting caught.
Don't act on the specifics - act on the system by invalidating it. What we need is a bit of circuitry that senses the radar from the camera and sends it back with a doppler shift (if that's how they measure speed) of some improbable velicity like 300mph. Even better would be to beam this out of the front of your car so that drivers ahead of you driving under the maximum also get captured by the cameras.
Get enough instances of unreliability and the whole system falls into disrepute.
Or do what some guys did at a motorcycle rally in the UK. Park a van in front of a camera (country lane). All stand on the roof. Drop trousers. Have a mate on a bike zip past the camera fast enough to trigger it.
Or don't break the speed limits.
The situation in the UK with these sorts of devices (plate obscurers, IR laser jammers and the like) is that the police prosecute the driver or owner of the vehicle in question for the crime of obstructing the police in the course of their duties. This is a much more serious crime than the speeding or red light ticket offence is.
The police also reputedly have a policy of recording the licence plate details of any vehicle which laser speed measuring devices cannot get a measurement; two or three such records and the police then pay the driver a visit to examine the car for the presence of jamming devices of this nature.
Finally, most if not all police vehicles have in-car video recording systems. The cameras of these systems are very infra red sensitive, so if a police driver follows a car which seems to have a glaring bright light on the back which is visible to the camera but invisible to the naked eye, then that police officer is quite likely to stop the car for a quick chat and an examination of the licence plate, with a view to charging the driver for obscuring the licence plate.
All in all, a GPS-based speed camera and red-light camera warning device such as I have fitted in my car is a much better investment; lets me know where the danger points are so I can behave myself at those specific places.
Detecting a flash as a method of determining when a picture is being taken is an anachronism at this point. All but the cheapest cameras these days are sufficiently light-sensitive to get better photos without the flash than with it, even when taking stills, and on top of that an increasingly large percentage of cameras are primarily designed for video and don't even *have* a flash unit. These concerns may not yet apply to the specific application for which this device is intended (because the cameras in question may be a bit behind the times), but that situation is likely very temporary. The devices will soon be obsolete, if they aren't already.
Perhaps a better way to make photography harder would be to illuminate the subject inconsistently (e.g., much more on one half than on the other) with a wavelength of light that is not visible to the human eye but normally is visible to most cameras. Post-processing can clean up such photos somewhat, but this is difficult to automate, especially if the illumination pattern is not a smooth gradient and extra-especially if the illumination pattern is different every time. Lens filters can be designed to filter out everything except visible light, of course, but that costs more, so most cameras don't have it. Filtering out just the wavelength of light that the device uses would be cheaper and easier, but then a new model of the device comes out that changes it...
@Peter A.: I've never seen a goblin (or any monster) wield or apply an expensive camera, despite the fact that I often leave the camera laying around on the dungeon floor due to the weight. (I think Tourist is the role with the lowest average carrying capacity at the beginning, and heaven help you if hunger forces you to eat poisonous corpses that have only a low chance of granting poison resistance. Sometimes I clear both Sokoban and Minetown before getting to the point where I could carry around tools other than the credit card and not be burdened.)
I live in São Paulo, Brasil. The city is infested with hundreds of speed cameras (expressways that used to be 80 kph are now 60 kph), red light cameras, pedestrian crossing cameras and even cameras that check if your “pollution inspection” is current. NOT A SINGLE ONE OF THEM has flashes. All the newer ones (like that ones that check the inspection) “read” the license in real time. Some check multiple things at once.
A Hungarian company has pretty good evil software that is used worldwide and it needs no flash.
@ Dan H,
The cameras of these systems are very infra red sensitive, so if a police driver follows a car which seems to have a glaring bright light on the back which is visible to the camera but invisible to the naked eye
I have just such a device and it's quite legitimate and was widely on sale a couple of years ago. It's a rearview "IR parking camera". The one I fitted to a friends car actually had a fault in that the dash board off switch only turned off the screen not the IR LEDs around the camera lense...
A company called Swann in Australia make suitable IR cameras and dash board mountable screens if you want to save a few bob and make your own review camera for night parking.
And in the UK it has to be IR because it's actually illegal to show a visable white light to the rear of the vehical or a visable read light to the front. There is a case of a milkman on an "electric float" being detained in December a few years ago and told he would be prosecuted because, he had a small Xmas tree (about six inches high) on his dash board with colourd lights and a santa sleigh with a dear with a red illuminated nose...
So most manufactures of rear parking sensors / indicators in the UK market use either IR or occasionaly the unlicensed microwave ISM bands (but you cannot use the X band frequencies around 11GHz that is licenced for traffic light control systems.
Now a thought occurs to me about IR illumination, one or two systems that give "rear proximity" also us IR devices that scan a fan of light backwards to be reflected to another sensor I wonder what the chance is of accidentaly getting the "waggon wheel effect" up on the police camera monitor screen? That is how easy would it be to use a scan frequency such that the difference frequency between it and the Police camera moniter emmited a moving object around 7Hz or other frequency that induces fits. The more of these devices are designed the greater the chance such a difference frequency is going to happen by accident.
The great thing about this is that if you save out the demonstration image ("And here's the same license plate with the noPhoto activated"), load it into gimp, run the alien map filter with high (but not equal) frequencies and 0/120/240° phaseshifts to essentially randomize the colour map, enough of the plate is *still* visible to provide a high probability match.
@div even better: crop the picture to just the 'white' area, select Colors->Auto->Stretch Contrast
Much less CSI :-)
Depending on the details of the font used by Ohio, I think that gives you enough to get 2 of 3 letters (perhaps all 3) and 3 of 4 numbers (and the last will be one of 3 or 4)
Looks like the 'left' (bottom) lamp fired late.
What no one has mentioned here is whether this type of "counter measure" actually works.
@Joseph They only lasted a couple of years, because the entities using them mailed out the tickets, and were too cheap to use any sort of delivery confirmation. And since "the ticket must have gotten lost in the mail" is extremely plausible, nobody ever paid the tickets.
It seems both trivial and obvious to deny renewals of vehicle registration or drivers' licensing to cars or drivers who have unpaid fines. There are several states which already do this for unpaid parking tickets. Rocket science this is not.
Current camera systems just take multiple pictures after the flash and/or flash multiple times. Thus an 'anti-flash' may only jam some pictures, due to technical limitations in the 'anti-flash' (e.g. recharging capacitors in time). Some cameras also work in a broad light spectrum (IR and visible). If the 'anti-flash' does not jam the hole spectrum used, the camera may got enough information to reconstruct the contour of the letters on a license plate ;-)
I suspect that in most jurisdictions it's illegal to "interfere with" either police equipment, or equipment put in place by road traffic authorities. This technique would certainly fall under most definitions of interference.
I suspect that it's actually an attempt to game the IndieGoGo system by getting funding for a 'product' that will shortly be outlawed explicitly. Oh, you want a refund? Sorry, you should have read the fine print of our fundraiser campaign...
I wonder if the lights will trigger from the flashes when a squad car is sitting behind you?
Because that would seem like a bad thing.
The issue around modifying the images makes them in the general case, unusable in court and affects the chain of custody. Digital cameras in the UK were a long time in coming for the most part due to the permissability of digital images in the absence of a human who could do a statement to say, "This is my image, I took it, it reflects what I saw at day, date time and place".
The issue the courts have is with the availability of means to verify the image contents. Film images have a long history of being produced in court, courts know how to handle them. Digital CCTV still requires someone to evidence the footage and is usually a component in the conviction of someone for an offence (i.e there is usually other physical or circumstancial evidence to support the case) and ultimately, the equipment could be seized an analyzed.
Once you've post processed the image to get the proof and the image is the pivotal piece of evidence you can no longer say the evidence has not been tampered with. Someone has to stand up in court and say, I didn't simply superimpose someones plate onto it.
For a speeding offence, it isn't worth the cost to persue, at least until something more serious happens and which case you're not fussed about the speeding anymore and its already morphed into something like dangerous driving.
I'm not saying this does or doesn't work, I have no idea but if there isn't a plate on the image, I expect it would simply be discarded (until there are sufficient numbers for people to care about)
I'd be much more interested in an E-Ink or LCD number plate which I can just change to be arbitrary values before I go through the camera.
In the USA, federal law requires a minimum 3 second yellow light. Municipalities that shorten this can be successfully challenged.
In most cases the red light cameras are owned and operated by a private entity, and many have been successful in getting legal (license/registration) penalties for not paying the ticket dismissed because it is not issued by a public authority, but a private entity.
The defense "I considered it unsafe to try to stop at that time" is probably pretty good. I can see where a good lawyer could successfully argue that without a prosecuting witness to argue otherwise, the law must err on the side of the defendant.
Just put mud on your license plate
There is a simple solution to the problem.
1. Go to City Hall and write down the license number of several prominent leaders.
2. 'Photoshop' the numbers into paper license plates.
3. Drive to known location of camera around 3 am.
4. Attach 'printed' license over your real one.
5. Drive through red light several times.
6. remove paper license
7. Go home laughing that the 'Mayor' just got several tickets...
"(b) the number - plate is not obscured, defaced or otherwise not legible"
And here is why these are legal and you're obviously not a lawyer: you are not obscuring, defacing or otherwise rendering illegible the plate - you're making it less photogenic. A human can still, always, read the plate. Certain specific technology perhaps can't, but the law doesn't state that it must.
This is why, in fact, this and similar products have been available for many many years without much harrah.
Yes, in NSW. Check the case law.
Regarding the printed license plate trick, that is apparently a known trick by high school students: photo a teacher's license plate, print it in color, put it on your car, and intentionally run red lights equipped with safety cameras. Needless to say, if a student were to ever cause a crash this way, there would be hell to pay.
MythBusters once tested multiple license plate obscurers against a safety camera--commercially available (aerosol, various plastic covers) and homebrew (cling wrap). The all failed to obscure the plate from the camera, and the only they were able to defeat the safety camera was at 200 mph, which very, very few production cars are capable of.
FWIW, despite license plate covers being apparently worthless against safety cameras, they're still in widespread use, even though illegal. Our local police here do close to zero traffic enforcement, and the only way to get pulled over for having one is probably if you're also DWB.
Also, while the camera will attempt to auto-read the number, a human can review the photo and video too and read the number if the computer can't. In fact, every red-light camera citation here is reviewed and signed by a human law enforcement officer to confirm that a violation did occur, preventing false positives, as stopping and legally turning on red will trigger the camera.
I've had people ask me why I object to the TSA, but not to traffic safety cameras. Simple. Dangerous driving kills, and it kills more people in the USA than a 9/11 every month. If a safety camera improves driver behavior and reduces T-bone deaths at large intersections, so be it. Some people argue that safety cameras increase rear-end collisions, but those are far less likely to be fatal than the T-bones they're offsetting.
On the other hand, the TSA not only provides zero security benefit, but between breaking TAT probes and medical equipment and discharging passengers' firearms, it's only a matter of time before they directly cause a death, despite the zero deaths they have prevented.
The word "jam" in reference to this phenomena seems wrong. It is actually an overexposure. If the camera could suddenly raise its F stop, decrease its exposure time or decrease its sensitivity (lower ISO) the image would be readable.
Jamming to me is radio interference which has a lot of destructive interference where the information is overridden and gone.
Well I thought a difference detector finds the moment when you are just in the middle of the beam and they are busy doing the doppler thing. Then a jelly jar sized sprytron fires and discharges a half ton capacitor through the 4-chamber klystron in your trunk. To test the contraption you hold a raw egg on a wooden spoon in front of the antenna. It has to explode immediately.
While I don't necessarily agree with the product, it brings to light what seems to be a misuse of technology.
The issue with people running red lights is that they are a traffic hazard right?
So we have the technology to see when a car ran a red light and obviously predict with reasonable accuracy when an approaching car is going to run a red light.
Why don't we use the technology to delay the green light in the opposite direction when it is believed that a car is going to run the light? If you want to snap a photo and send a ticket too, that's fine as well.
Seems to me if we really cared about making the roads safer over just writing tickets, we would apply the technology appropriately.
@Randy: My main objection to these cameras is that I can't face my accuser. If a mistake happens, then there's no way to win.
I keep hearing this more and more often. Here in the UK, if a speed camera catches you, you get a ticket in the post for a fixed penalty. You can pay the penalty (and get some points on your license - if you accumulate enough, various bad things happen) and let that be the end of it, or you can refuse to pay the penalty and go to court instead, where you'll get to face a member of the police force accusing you and see the evidence against you; if a mistake has been made, you'll be acquitted, otherwise you'll have to pay court fees on top of the fine (though I am told in practice the police often fail to turn up to these). The penalty is a way of shortcutting the whole process for the more frequent case where you know you don't have a leg to stand on - you are not denied your rights if you are mistakenly accused.
Is this not the way it works in the rest of the world?
As I recall the Vehicle Lighting Regulations actually prohibit any lights other than those permitted, which bans this for a start.
The only cameras that seem to actually be interfered with by the sprays are the ANPR ones on police cars. This is obvious to the police officers behind you, who will not be best pleased.
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