03-31-2011, 02:24 AM
Whether you're commuting to work, or on your way home from a late night at the movies, getting caught at a red traffic light is a frustrating thing when there are no other humans anywhere in sight.
Meanwhile, you're sitting there for minutes on end, twiddling with your XM radio dial or watching water vapor condense in the sky.
Guess what -- you can learn how to trigger demand-actuated traffic lights and save yourself some time and maybe a little gas.
Look for the trigger
This method won't work for every light. For example, in city block grids, the lights are more often than not programmed by timer -- that is, they're set to coordinate with the lights near them so that most poor suckers won't get caught every hundred yards (see Hackers). Other coordinated traffic systems are "actuated-coordinated" which means they will not immediately turn green even if your vehicle is detected. This allows for major corridors to remain coordinated while you wait for your time in the cycle. Lights that aren't pre-programmed are called "demand-actuated" lights, because they only change their state when a vehicle rolls up to them.
To find out if you're sitting at a demand-actuated stoplight, look for the inductive-loop detector embedded in the asphalt in front of you. An inductive-loop detector is a loop, or double-loop, of wire that's been embedded into cut pavement and then tarred over. It detects the presence of conductive materials, like the steel or iron used to make your car, or aluminum or titanium in a bicycle. Aluminum bicycle rims, positioned appropriately over the sensor, are adequate.
You can also look at the traffic signal arm for other methods of detection such as cameras or radar sensors. These are newer and much more reliable technology.
Position yourself appropriately
Triggering a demand-actuated stoplight is almost always as simple as positioning yourself over it. Sounds like a no-brainer, but many people don't realize that they hit the brakes too late and ended up mostly in the crosswalk, or that they're actually fifteen feet behind the detector. Be sure to stop with your front bumper close to, but behind the stop bar at the intersection.
For most small cars, scooters and motorcycles, triggering a green traffic light can be as simple as moving a little closer to the center of the lane. So if it's not triggering, try backing up, changing direction slightly, and rolling over it again.
If you're on a bicycle, you can trigger an inductive loop detector more easily by laying your bike frame down flat on the ground until you receive a green light. However, the only way to guarantee a green light, is to press a pedestrian button.
Tip: Some cities use camera or radar detectors instead of inductive-loop detectors. If you spot a camera and are on a motorcycle or scooter, no special action should be required to receive a green light, but you can position yourself broad-side to the camera to let it pick up your presence more easily.
Tip #2: These camera detectors sometimes have a small red light that will light up to show that it has triggered and therefor detected your presence.
Magnetize
Buy a neodymium magnet to trip the sensor. If positioning yourself properly over the loop doesn't work, a heavy-duty magnet should do the trick. Neodymium magnets are rare earth magnets, formed from an alloy of neodymium, iron and boron. They're currently the strongest type of magnet available, and (yippee!) they can be purchased online. Protect the magnet with a pill case or a set of washers, and then tape the magnet to the bottom of your car or vehicle.
While there is significant debate as to whether a magnet can be strong enough to alter the electromagnetic field which triggers the sensor, you may decide to give it a shot. You can buy a commercial magnet or make your own.
* If you do make your own magnet trigger, be very careful when handling them as they're very strong. Wear eye protection when handling them because they're very brittle, and if they slam together or against any other surface, a piece of magnet can easily get into your eye.[5] Protect the magnet before exposing it to the elements (e.g. put it in a chrome plated pill holder with a rubber ring). Never bring these magnets close to anyone with a pacemaker (the strong magnetic field can interfere with its operation), children (who can get their fingers pinched between two magnets, ingest one, or get a shard in their eye), floppy disks, credit cards, magnetic I.D. cards, cassette tapes, video tapes, televisions, VCRs, computer monitors, or any other electronic appliances.[5]
* Attach the magnet case to the bottom of the vehicle with epoxy paste or screws. Where you place it on a car will depend on what kind of loop you tend to come across. If you want to cover all the bases, place magnets along the center and the sides (in line with the wheels). If you used epoxy paste, let it dry and check that the magnet is secure regularly--you don't want this magnet flying off of your car at 70 miles per hour on the highway.
* If you ride a two-wheeled vehicle, you can attach the magnet to your shoe with epoxy paste so that when you pull up to an intersection, you're able to spot the wire and put your shoe right over it with the magnet.[6]
Call in a fix-it
Call your local department or bureau of transportation. In a study conducted in the 1980s, the state of New York discovered that fully 25 percent of the demand-actuated detectors were malfunctioning. Which makes sense, when you consider that these fragile wires are close to the surface of the asphalt and subject to all manner of indignities, including the weight of hundreds of thousands of vehicles.
If it appears that a particular light on your route is broken, write down where it is, what time you stopped at it, traffic conditions and how long you waited. When you get the chance, contact your local transportation authority and explain your concerns. If you've documented the incident and you still get a ticket, a good cop or judge will likely let you off the hook. But make no mistake -- it's still illegal to disobey a red light. Turn right instead (where permitted), then do a three point turn or U-turn to get back on your route.
Just because you've learned a few simple tricks doesn't mean that your commute home is going to be frustration-free. But with a little know-how, hopefully you can side-step faulty lights or fool the robots into setting you free a minute or two early.
http://www.youtube.com/watch?v=8GAacxGiV4A
Meanwhile, you're sitting there for minutes on end, twiddling with your XM radio dial or watching water vapor condense in the sky.
Guess what -- you can learn how to trigger demand-actuated traffic lights and save yourself some time and maybe a little gas.
Look for the trigger
This method won't work for every light. For example, in city block grids, the lights are more often than not programmed by timer -- that is, they're set to coordinate with the lights near them so that most poor suckers won't get caught every hundred yards (see Hackers). Other coordinated traffic systems are "actuated-coordinated" which means they will not immediately turn green even if your vehicle is detected. This allows for major corridors to remain coordinated while you wait for your time in the cycle. Lights that aren't pre-programmed are called "demand-actuated" lights, because they only change their state when a vehicle rolls up to them.
To find out if you're sitting at a demand-actuated stoplight, look for the inductive-loop detector embedded in the asphalt in front of you. An inductive-loop detector is a loop, or double-loop, of wire that's been embedded into cut pavement and then tarred over. It detects the presence of conductive materials, like the steel or iron used to make your car, or aluminum or titanium in a bicycle. Aluminum bicycle rims, positioned appropriately over the sensor, are adequate.
You can also look at the traffic signal arm for other methods of detection such as cameras or radar sensors. These are newer and much more reliable technology.
Position yourself appropriately
Triggering a demand-actuated stoplight is almost always as simple as positioning yourself over it. Sounds like a no-brainer, but many people don't realize that they hit the brakes too late and ended up mostly in the crosswalk, or that they're actually fifteen feet behind the detector. Be sure to stop with your front bumper close to, but behind the stop bar at the intersection.
For most small cars, scooters and motorcycles, triggering a green traffic light can be as simple as moving a little closer to the center of the lane. So if it's not triggering, try backing up, changing direction slightly, and rolling over it again.
If you're on a bicycle, you can trigger an inductive loop detector more easily by laying your bike frame down flat on the ground until you receive a green light. However, the only way to guarantee a green light, is to press a pedestrian button.
Tip: Some cities use camera or radar detectors instead of inductive-loop detectors. If you spot a camera and are on a motorcycle or scooter, no special action should be required to receive a green light, but you can position yourself broad-side to the camera to let it pick up your presence more easily.
Tip #2: These camera detectors sometimes have a small red light that will light up to show that it has triggered and therefor detected your presence.
Magnetize
Buy a neodymium magnet to trip the sensor. If positioning yourself properly over the loop doesn't work, a heavy-duty magnet should do the trick. Neodymium magnets are rare earth magnets, formed from an alloy of neodymium, iron and boron. They're currently the strongest type of magnet available, and (yippee!) they can be purchased online. Protect the magnet with a pill case or a set of washers, and then tape the magnet to the bottom of your car or vehicle.
While there is significant debate as to whether a magnet can be strong enough to alter the electromagnetic field which triggers the sensor, you may decide to give it a shot. You can buy a commercial magnet or make your own.
* If you do make your own magnet trigger, be very careful when handling them as they're very strong. Wear eye protection when handling them because they're very brittle, and if they slam together or against any other surface, a piece of magnet can easily get into your eye.[5] Protect the magnet before exposing it to the elements (e.g. put it in a chrome plated pill holder with a rubber ring). Never bring these magnets close to anyone with a pacemaker (the strong magnetic field can interfere with its operation), children (who can get their fingers pinched between two magnets, ingest one, or get a shard in their eye), floppy disks, credit cards, magnetic I.D. cards, cassette tapes, video tapes, televisions, VCRs, computer monitors, or any other electronic appliances.[5]
* Attach the magnet case to the bottom of the vehicle with epoxy paste or screws. Where you place it on a car will depend on what kind of loop you tend to come across. If you want to cover all the bases, place magnets along the center and the sides (in line with the wheels). If you used epoxy paste, let it dry and check that the magnet is secure regularly--you don't want this magnet flying off of your car at 70 miles per hour on the highway.
* If you ride a two-wheeled vehicle, you can attach the magnet to your shoe with epoxy paste so that when you pull up to an intersection, you're able to spot the wire and put your shoe right over it with the magnet.[6]
Call in a fix-it
Call your local department or bureau of transportation. In a study conducted in the 1980s, the state of New York discovered that fully 25 percent of the demand-actuated detectors were malfunctioning. Which makes sense, when you consider that these fragile wires are close to the surface of the asphalt and subject to all manner of indignities, including the weight of hundreds of thousands of vehicles.
If it appears that a particular light on your route is broken, write down where it is, what time you stopped at it, traffic conditions and how long you waited. When you get the chance, contact your local transportation authority and explain your concerns. If you've documented the incident and you still get a ticket, a good cop or judge will likely let you off the hook. But make no mistake -- it's still illegal to disobey a red light. Turn right instead (where permitted), then do a three point turn or U-turn to get back on your route.
Just because you've learned a few simple tricks doesn't mean that your commute home is going to be frustration-free. But with a little know-how, hopefully you can side-step faulty lights or fool the robots into setting you free a minute or two early.
http://www.youtube.com/watch?v=8GAacxGiV4A
![[-]](https://mach1club.com/images/collapse.png "[-]")
