Slashdot Mirror
Traffic Light Control For The Masses
uniformed1 writes "Eliminating red lights along the routes of their vehicles can give
emergency response teams the few extra critical minutes that can save
lives and property. A front page article
in today's Detroit News details
the emerging problem with a device that is now being made available to
the public -- a traffic light changer. Originally intended only
for emergency vehicles, the $300 MIRT (mobile infrared transmitter)
emits an infrared beam that signals traffic signals to turn green and
gives the vehicle the right-of-way. It is only a matter of time
before self-centered drivers start using the devices widely to skirt
traffic congestion, which is creating fears that chaos will
ensue." Maybe if everyone had these, it would lead to smarter intersections.
www.themirt.com has a lot of info on these devices. Even a dealer list of where to get one. Man, I'm tempted...
-mikey
Indeed, as one commentator noted, this device was imagined, if not implemented, by the phone phreaks, and was named the "Chrome Box" - just a bit of a tidbit from my misspent youth!
eikimartinson.com
In most cities, the light goes green for the guy with the transmitter, but a white strobe light on the same pole goes off too. If all lights went red, but the strobe still went off, the should be enough to make the driver confident that all directions are indeed red.
When information is power, privacy is freedom.
your average CCD will detect IR. Don't believe me? Pull out your camcorder and aim a remote at the camcorder. It looks like white light. I know where I live, we have CCD DOT cams at almost every intersection. It would be easy to pick out the car emitting the bright flashes.
I've worked for several ambulance companies and spent a good amount of times in cities on the east coast, and I have never seen an ambulance with this device installed.
On top of that, traffic regulations technically require ambulances to stop at red lights and proceed through after the've verified that traffic is stopped. I think the siren would be more effective than a sudden red light.
Maybe I can see a use for turning it green, as it would help get the traffic in front out of the way, give them space to pull over, but for this to work, they'd have to activate it from a distance. Since IR isn't focused like a laser, I doubt it would work from a great distance.
I guess the slashdot editors editors weren't too into the hacking/phreaking scene back in the day. This was documented some 10 years ago.
If you want proof, consult the google time machine. Scroll down or search for "Chrome Box".
Here is some more information with pictures of the Optocom sensors (mounted to the signals) and of EMS and Fire transmission units.
I assume the old ones where nothing more than an infared flashlight, and the "upgraded" ones use some sort of modulation something like a TV remote. The picture in the article shows what looks like a 3rd brake light with a lighter plug. It probably costs $20. They're basically charging $300-$500 for a long range TV remote control
but it is illegal: "impersonating an emergancy vehicle"
that is a MASSIVE fine.
that does stop people quickly, too bad it wasnt a felony.
just like purposefully impeding an emergancy vehicle, -- former EMT.
people that look in their rear view mirrors, while attempting to ignore an ambulance should be in PRISON.
Infared (Heat) and Infared (Light) are two different things.
The former is "far infared" (more far away from the visible-light region of the EM spectrum) and the later is "near infared" (closer to the visible-light region of the EM spectrum)
In order for a CCD camera to detect *heat* infared, you'd have to heat the thing up to the point where the metal would be pretty damn close to glowing -- and at that point, it's releasing visible light/near-IR also, so it's a moot point.
Your hands and PC are *not* releasing the same kind of IR energy that is talked about in this article. If it were possible to control release of such energy, then we'd have heat rays.
Sorry, but this is a total scam, I am the former Supervisor of Electronics and Communications for a large City's Traffic Signal Department and this stuff was my life for 10 years.
Emergency vehicle signal preemtion works in one of three ways... hardware connection from the fire house to the closest signals, RF signal from truck to signal cabinet (would only be on some special routes due to the cost) and magnetic induction loops in the roadbed.
The little periscope looking devices are not infrared detectors. They are vehicle detectors that use microwaves to count the traffic and see how long the cue of traffic is at the signal. That length of cue has an impact on the traffic signal timing ie: cue > 10 cars, change the green until it is 2.
Induction loops are the squares, rectangles and diamond patterns you see in the road (normally in a left turn lane). They are single conductor wire that create an induction coil for detecting the change in magnetic field when a large metalic mass is over top, which then triggers the lights.
A fully pre-emptive signal is not very effective for general use and most City's will only have a percentage of them. With 2000 signals under central control only 100 - 150 would have this type of pre-emption.
You are better off flashing your high beams as you approach a red signal. You get the same placibo effect and you aren't out $300.
Most traffic light sensors these days use a combination of infrared and visible light strobes, as well as encryption, to signal the light to change. These infrared emitters wouldn't do anything . Check out 3m Opticom system for more information.
The traffic light control system itself is called Opticom . It is patented and manufactured by 3M.
It operates using very short pulses of light (< 10uS) occuring at a precise frequency (usually crystal controlled). The normal pulse rate is about 10Hz. An optional rate of around 12.5Hz can be used to give priority to other vehicles (ex. ambulance vs firetruck).
The system is configurable and normally set to give a green light to the emergency vehicle (helping to clear traffic) but it can also be set to go red in all directions.
Well at least in my town (wilmette, IL) and most cities in the Chicagoland area, there are strobe light detectors and a white flood that will light and change the traffic light green when an emergency vehicle approaches the intersection because of a strobe light blinking at a specific frequency usually mounted on the front of a ambulance, fire engine, etc. .... I can just image people's excuse.... "Officer we where just having a disco party in the car" :o)
The devices that are used around here don't turn the upcoming light green for the emergency vehicle. They turn the lights in all directions of the upcoming intersection red. This ensures that the emergency vehicle is the only one with the right to enter the intersection. Makes sense to me...
Weight sensors are for truck weigh stations. You're probably referring to an induction coil embedded in the road farther away from the light so it knows you're coming.
While I hesitate to put you squarely in the club to which also belong those people who flap fresh polaroids in the belief that doing so makes them develope quicker, I have to take what you say with a measure of skepticism.
A quick, but admittedly not thorough, google search revealed no such devices. Furthermore, I have lived in Tallahassee, Florida all my life. One of your child posters said that they had these devices in Tallahassee and I have never heard of them nor have I seen them. I have also never seen people flashing their lights at intersections. And Tallahassee is not a big town.
I should like to mention, moreover, that my father has been a Traffic Engineer in Tallahassee, Florida for over 15 years . I just now called him up and asked him if he had ever heard of anything like this and he said he had not. He, a professional traffic engineer, said they sounded like a bad idea.
If you're interested, you might submit some sort of proof of your claims.
If it makes you happy flashing your lights, then I'm happy for you. But until I see better evidence, I'm going to remain skeptical on the proposition that there is a causal relationship in evidence here.
Wouldn't work if it was done right.
I use an infrared remote to access my condo - it uses an infrared remote system that's fairly simple, yet effective:
-The remote (much like garage door openers) uses a rolling pseudo-random number sequence. The remote generates a code based on the next number in sequence from a random number generator seeded with a known key for that particular remote (the main controller needs to be "paired" with the remote before use so it knows what seed each remote is using).
-The controller keeps track of all of the remotes for the building and pre-computes the next 256 valid codes that each remote will generate based on the seed exchanged when the remote is paired.
When a remote triggers, it sends the random number code (NOT the key) by way of infrared to the controller receiver. The controller checks to see if the number the remote transmitted is in the next 256 valid numbers for that particular remote, if so, you get in. If not, you don't and the attempt is logged.
If you press the button more than 256 times (playing with the remote button for example) when you're not around the sensor, none of the precompute codes will match the next time the remote is used and it will be useless until re-paired.
Even if you capture the code being sent from the remote, you won't know the key that the random number generator is using in that particular remote to generate the number sequence, or any of the subsequent numbers that the remote would generate. You'd only capture the code that was sent, and once that was used, it wouldn't work again anyway.
If a remote key is compromised, it's simple to simply deactivate that particular remote key. If the system is brute-force attacked, it can either deactivate the sensor that's being attacked, or just call security to the appropriate location.
N.
"Nothing strengthens authority so much as silence." - Charles de Gaulle
Just do a Google search for "chrome box" and toss in some other keywords for good measure like traffic, phreak, hack, etc. Plans for these things as well as the proper timings and patterns for different cities and regions have been available for years. I built one for gits and shiggles over 10 years ago and used to play around with it. The novelty quickly wore off, however, because of the standard Garfield ism of "it's not the having, it's the getting". I used up all of my fun trying to figure out the proper timings and patterns and then actually implementing the box proved to be quite boring.
PepperHacks - Hacking the Pepper Pad
We have a few around here in PA. The ones that change if you "flash to pass randomly" usually have a camera-like thinger near the light itself. And yes, if you're lucky enough, you can sometimes get the right frequency to get it to change.
In NYC almost all of the streets are one way only. Turning the lights red will just make impossible for emergency vehicles to move at all since they won't even be able to drive the wrong way down streets since traffic stuck at the red lights will be blocking them.
Many of the cities (such as Revere) in the Boston area already have very smart intersections. Drive up to almost any red light here, and the inductive loop detector will notice you're there, and the lights will promptly change (if, of course, there's no line of traffic approaching on a greater right-of-way street... these are truly smart). Some actually don't use inductive loops anymore, because the contacts wear down over time, and are hard to adjust if not installed properly. Instead, they've been using those optical scanners the infrared transmitter works with. However, these scanners don't just pick up infrared - they are smart enough to detect normal vehicles approaching, and adjust the lights accordingly. There's really no reason to cheat. Also... many cities around here don't even USE the infrared transmitters. At least in Revere, the lights are centrally controlled. When a fire truck, for example, is dispatched - its course is entered into the system and the lights change accordingly, clearing traffic IN ADVANCE of the vehicle even reaching the intersections. I noticed this just a few weeks ago, and was in awe at how advanced and dependent on technology we've actually become, and just how cool it is we can save those few lives that might have needed just one or two seconds faster response time.
and that's why folks, you pull over, ALL the way over.
Unless you are on a multilane highway (read: freeway/expressway.), in which case you get all the way into the righthand lane and keep going. DO NOT STOP ON THE FUCKING FREEWAY. Just get over to the right lane and let the damn ambulance/cop/firepeople go around you.
Sorry, I've been wanting to vent this for a long time. In Oregon, you are not required to pull off the road and/or stop for an emergency vehicle when you are on a multilane (2 or more lanes in both directions) highway. For some stupid reason, about half the people don't understand that all you have to do is get into the righthand lane and keep going.
"Alcohol, Tobacco, Firearms, and Explosives" should be a convenience store, not a government agency.
Also, it solves the problems motorcycles have with being too light to trigger the pavement sensor.
You may have to explain this one... too light?
The system used here works the same as a metal detector. A wire loop is embedded in the pavement (and it's not that difficult of a process you cut, insert the loop, and tar-seal) and it simply detects metal near the loop (because it changes the resonant frequency of the inductor). I've got two friends that ride motorcycles and they say it has never been a problem for them.
"Alcohol, Tobacco, Firearms, and Explosives" should be a convenience store, not a government agency.
I'm not so sure that technique would be very effective against red light/ toll cams. Here is the spec. sheet for Ilfords special purpose traffic surveilance film; it doesn't seem to be particularly sensitive to infrared. Most IR film is sensitive in the 800-900 nanometer range; this film gives up at about 775.
The other thing to think about would be that these surveillance cameras (to photograph red light runners and whatnot) operate with flash and a pretty fast shutter speed. (1/500 or 1/1000th of a second is quick for night use; it must be powerful flash.) There is the chance that since your MIRT is flashing at say, 14Hz, and typical flash tube duration is only 1/1000th of a second or so (which means there is only IR coming out of your MIRT for 14/1000's of any given second), that the surveillance camera has a fair enough change of snapping the picture when the MIRT is not emanating light.
What would probably be effective would be to rig a bright source of visible light near the license plate facing outwards (towards a potential camera) so that it would oversaturate the film in the vicinity of your license plate. Ideally, this could be a slave flash that would be triggered by the surveillance camera's flash, so that it would definitely be firing when the picture was taken.
Either way, we have no red light runner cams or any surveillance cams (other than DOT video, which typically doesn't have the resolution to read plate numbers) in this area. All of this type of surveillance is done by concealed police. So, I have no incentive to test this around here.
Think of a RSA SecurID token. A 6 number sequence that both the token and the authenticator know that changes at preset intervals.
Strangely enough, the USPS (Yes, the mail) is up there with the police, fire and EMS in being able to go thru traffic lights.