Catch up on stories from the past week (and beyond) at the Slashdot story archive


Forgot your password?
Science Hardware

Traffic Light Switcher Makes Critics See Red 600

An anonymous reader writes "According to a Yahoo/Washington Post article: 'It sounds like a suffering commuter's dream come true: a dashboard device that changes red traffic lights to green at the touch of a button. Police, fire and rescue vehicles have had access to such equipment for years, but now the devices are becoming available to ordinary motorists thanks to advances in technology and a little help from the Internet. Safety advocates are outraged, and news accounts in Michigan last week led to politicians there seeking a ban on the gadgets'." Update: 11/06 02:25 GMT by S : A previous Slashdot story mentions the device, though not the Michigan legislature's subsequent ire.
This discussion has been archived. No new comments can be posted.

Traffic Light Switcher Makes Critics See Red

Comments Filter:
  • Chrome box (Score:2, Informative)

    by Anonymous Coward on Wednesday November 05, 2003 @10:20PM (#7403201)
    Did we forget the old chrome boxes?
  • by pixel.jonah ( 182967 ) on Wednesday November 05, 2003 @10:24PM (#7403234)
    FCC controls RF, nobody controls light (IR)
  • If you want one (Score:4, Informative)

    by Anubis333 ( 103791 ) on Wednesday November 05, 2003 @10:24PM (#7403235) Homepage
    They are on sale here []
  • by seinman ( 463076 ) on Wednesday November 05, 2003 @10:34PM (#7403317) Homepage Journal
    Some lights have video cameras on them for this very purpose. They're programmed to tell how far back the cars are lined up based on the contrast between a car and the road. They have the added benefit of catching those who run red lights.
  • Re:I want one! (Score:2, Informative)

    by SuperDry ( 636335 ) on Wednesday November 05, 2003 @10:35PM (#7403335)
    They have been illegal in California for at least 20 years.
  • by KillerBob ( 217953 ) on Wednesday November 05, 2003 @10:41PM (#7403374)
    Except that the emergency vehicles are often caught behind traffic when they trip lights like that. Until weenies stop using the lane on the right that peters out 15m past the intersection to get past traffic at red lights, the emergency vehicles would be pretty much stuck if they aren't at the front of the line when the light goes red....

    As you know, them being at the front of the line means they wouldn't need to trip the light... they just need to put the flashers on, wait for traffic to stop, and go. :)
  • Re:I want one! (Score:0, Informative)

    by Anonymous Coward on Wednesday November 05, 2003 @10:55PM (#7403471)
    Poor you. I realise we live in the age of 'instant gratification', but perhaps you can take a few precious minutes out of your very important life to realise that traffic lights are in place for a reason.

    Are you really in that much of a hurry? If so, perhaps you need to examine why that's the case.

  • by aardvarkjoe ( 156801 ) on Wednesday November 05, 2003 @10:59PM (#7403494)
    Moderators, read the low-rated replies to the parent. Making all lights go red is workable in low-traffic situations, but in typical city traffic, doing so will just cause things to grind to a halt.

    Working around the problem -- that people are impersonating emergency vehicles and therefore causing havoc -- by destroying the usefulness of the devices is the wrong way of handling this.
  • Already done. (Score:5, Informative)

    by s20451 ( 410424 ) on Wednesday November 05, 2003 @11:49PM (#7403766) Journal
    They already do that. They're called proximity detectors, and they determine when cars are sitting on top of them. They work based on induction [].

    Sometimes you can see where they were embedded in the road, especially if the light was retrofitted. Look for a patched-over hole in the pavement directly underneath where the first car would pull up at a stop light.

    That is why some lights only change when your car is sitting there. For additional fun, you might be caught behind some dingus who, for some reason, stopped too far back to trigger the sensor. You're going to be there a while.
  • by Chemical ( 49694 ) <nkessler2000 AT hotmail DOT com> on Wednesday November 05, 2003 @11:50PM (#7403770) Homepage
    This AP Story [] talks about how Sen. Mike DeWine, R-Ohio, wants to make distribution and use punishable by up to a year in jail and a $10,000 fine. This has quickly gone far beyond Michagin

    These things are no joke and I hope this bill gets through.

  • by afidel ( 530433 ) on Wednesday November 05, 2003 @11:56PM (#7403809)
    and their usage to see through clothing to see naked skin is utturly rediculous

    You've obviously never seen This [] site or ones like it dedicated to the Sony camcorders with Nightshot and their ability to see through thin clothing. Of course it uses near infrared instead of xrays but the same principal.
  • by Anonymous Coward on Thursday November 06, 2003 @12:03AM (#7403850)
    It was kinda fun cruising through town, never hitting a green.

    If that's your kind of fun. I don't know why you'd want use a flasher. I prefer to never hit a red light.

  • by DarkAce911 ( 245282 ) on Thursday November 06, 2003 @12:44AM (#7404051)
    I used to be a paramedic and the lights don't work the way you guys thinks. It is a first come first serve type of operation. The first unit that trips the signal gets the green light, all other lights go red. All emergency vehicle drivers are trained to stop on red and then go. The two ambulance or fire truck has happened in the past. Alot of places lost emergency workers to this type of thing in the 50's and 60's. Now running thru a red light and hitting someone will get you personely sued.
  • by apankrat ( 314147 ) on Thursday November 06, 2003 @01:35AM (#7404282) Homepage
    Much simplier approach, which is widely used here in Canada and
    in the most of Europe, is to embed sensors in a form of loops of wire
    into the road on each side of the intersection. The loop can sense []
    the car directly above it, which allows streetlight controller to learn
    the length of the line-up on every side and switch the lights accordingly.

    Simple design rules :)
  • Overview (Score:4, Informative)

    by upt1me ( 537466 ) on Thursday November 06, 2003 @01:42AM (#7404321) Homepage
    Explanation of Traffic Signal Preemption (Stoplight Changing)

    The normal operation of any traffic signal controlled intersection is designed for the maximum and efficient throughput of vehicular traffic.

    Unfortunately, a common occurrence at any intersection is traffic back-up, which can require many signaling cycles to clear. Without the ability to change the operation of the traffic signals themselves, police and emergency response vehicles can also be forced to sit in traffic, thus dramatically increasing their response times to crime scenes and fire or medical emergencies.

    Furthermore, even without heavy traffic, a police or emergency response vehicle entering a traffic signal controlled intersection at a high rate of speed places all motorists (and sometimes pedestrians) at extreme risk.

    The MIRT is an optical communications system that allows equipped vehicles to alter the normal operation of traffic signals.

    An overview of a typical scenario is as follows:

    A fire truck is dispatched to an emergency.

    The fire truck is equipped with multiple emergency warning lights and a siren... The fire truck is also equipped with a preemption transmitter, which, in operation, is a high intensity forward-facing strobe light that is flashing at a rapid rate - much faster than normal attention-getting lights on the fire truck.

    When the fire truck approaches within 1,800 feet (line-of-sight) of a preemption-equipped traffic signal controlled intersection, the preemption detector (normally mounted on the cross-arm that suspends the traffic signal) "sees" the fire truck's preemption transmitter and locks onto its flashing strobe.

    Once the traffic signal "sees" the fire truck, it begins to initiate a "preemption sequence" of the actual traffic signal that is different from normal operation.

    If the fire truck already has a green light, the light will remain green. Any other direction that also has a green light (usually the opposite direction) will first get a yellow light, then red.

    When all of the other directions are then red, and the fire truck's direction is the only one that is green, the left turn arrow will illuminate (if one exists), and a brilliant white flood lamp mounted near the traffic signal will begin to flash. This flood lamp tells the driver of the fire truck that he now has control of the intersection, and complete right-of-way.

    If the fire truck has a red light, any other direction that has a green light will transition to yellow, then red. When all the directions (including the fire truck's) are red, the traffic signal facing the fire truck will then turn green, along with the left turn arrow (if one exists), and the brilliant white flood lamp will begin to flash.

    Once the fire truck has passed through the intersection, optical communication with the preemption detector (on the traffic signal) is lost. At that time the traffic signal will default back to normal operation. Conversely, until the fire truck passes through the intersection, it will have a green light, regardless of the time duration.

    If several intersections are within the 1,800 foot range of the fire truck's preemption transmitter, they will all respond accordingly to the above operational description.

  • Or.... (Score:2, Informative)

    by Bagarre ( 623181 ) on Thursday November 06, 2003 @10:55AM (#7406818) Homepage
    You can just put a strong magnet on the bottom of your bike. I have an old hard drive magnet on the frame of my Sporty and it works great! Don't even need to glue it on. You ever try to pull one of those off of a refrigerator?
  • by Valdrax ( 32670 ) on Thursday November 06, 2003 @11:41AM (#7407242)
    Thanks, jackass. We have porn-monitoring software at my workplace, and I probably just got tagged.

Logic is the chastity belt of the mind!