Traffic Light Control For The Masses 824
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.
Here's a link to a place that makes them... (Score:5, Informative)
-mikey
Re:Here's a link to a place that makes them... (Score:2, Informative)
Careful of local laws. Chicago crime bo...er mayor banned these early last year (which probably means that the Illinois gov. office sells them)
Chrome box (Score:2, Informative)
Re:Change the Behavior (Score:5, Informative)
Re:Illegal? (Score:5, Informative)
Rarely used (Score:4, Informative)
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.
Could this be the a classic Chrome Box? (Score:5, Informative)
If you want proof, consult the google time machine [google.com]. Scroll down or search for "Chrome Box".
More info about optocom sensors (Score:5, Informative)
Re:Rarely used (Score:3, Informative)
Re:Plans? (Score:5, Informative)
Re:Illegal? (Score:1, Informative)
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.
Re:Illegal? (Score:3, Informative)
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.
Signal pre-emption is not IR it uses inductionloop (Score:1, Informative)
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.
Re:Here's a link to a place that makes them... (Score:5, Informative)
Oh, and I don't want to be you when the cops pull you over. In Chicago it's a $4000.00 fine and 30 days in jail.
They are easily detected, they blast a massive floodlight of IR.
I welcome every complete moron that buy's these to use them... just like the police radar jammers.
Outdated (Score:3, Informative)
Opticom (Score:5, Informative)
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.
It's all ready been done (Score:1, Informative)
A different idea (Score:2, Informative)
Re:We have light-sensitive systems in the UK (Score:2, Informative)
Re:We have light-sensitive systems in the UK (Score:2, Informative)
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.
Re:No Encryption keys? (Score:5, Informative)
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.
Re:Plans? (Score:2, Informative)
Re:Thought this was an urban legend. (Score:3, Informative)
Unworkable in cities? (Score:1, Informative)
Boston (Score:2, Informative)
Re:Ambulance drivers don't go full speed (Score:3, Informative)
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.
Re:Once again, Slashdot trumps logic for technolog (Score:4, Informative)
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.
Re:This could also be used ... (Score:2, Informative)
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.
Comparing it to something geeks understand (Score:3, Informative)
Think of a RSA SecurID token. A 6 number sequence that both the token and the authenticator know that changes at preset intervals.
FYI (Score:2, Informative)