Traffic Lights That Don't Trip

GoldenMotor.com

Fulltimer

New Member
Aug 13, 2010
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Saint Augustine, FL
Here is an extract out of a booklet on bicycling in Florida. I don't have anything about other states.

Terry

WHEN TRAFFIC LIGHTS DON'T TURN

Always stop and wait for red lights. You not only ensure your safety, but you also increase respect for cyclists as law-abiding road users.

But some traffic lights don't turn green until they receive a signal from a metal detector buried in the pavement. Some of these detectors do not respond to bicycles.

You can recognize the detector by a square or octagonal pattern of thin lines in the pavement, where slots were cut for the detecting wires. The detector is most sensitive if you ride along one of the wires. (Sometimes, the slots for the wires are not visible, as the street has been repaved since they were installed).

If your bicycle doesn't trip the detector, you have to wait for a car to do it, or else you have to go through the red light. Going through the red isn't against the law, because the light is defective. If you ever have a crash or get a traffic ticket because a traffic light won't turn green, it's the fault of whoever installed the detector.

Detectors that work for bicycles are available at little or no additional cost. Design guidelines exist for these detectors. If you want to promote better conditions for bicycling, alert your government officials about road conditions of any type that are unsafe for bicycling. Let them know that they are responsible to make the roadways as safe as possible for all types of vehicles, and that accommodation of bicycles is important to you. Getting involved at the local level can be very effective.
 

biknut

Well-Known Member
Sep 28, 2010
6,653
475
83
Dallas
I always give the light a chance, but I only have the patience of a chopping block. After I give it a fair chance, I just run it.
 

Allen_Wrench

Resident Mad Scientist
Feb 6, 2010
2,784
26
36
Indianapolis
Didja ever get the lights that sometimes don't even trip for cars??? Well, we have them in Indy. And they're annoying as f&^%$&! Often I'll stick the old van in reverse, then drive, as I rock the thing on top of the sensor pad. Sometimes that works. Usually I'll just turn right on red and then turn around back to the intersection if I needed to go straight. It's a real drag though.
 

DuctTapedGoat

Active Member
Dec 20, 2010
1,179
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Nampa Idaho
I keep a rare earth magnet on my bike for when that happens. Really, only two situations call for it. One is if I'm by myself in the middle of the night and there's no cars anywhere, but my bike isn't ferrous enough to trip the magnetic sensor, so it stays red on me. The other is if I'm in the front of the line in a left turn lane - I've had it not trip for a whole line of cars before.

Someone told me they sell a spur like attachment for boots, as a lot of motorcycle riders even have this problem with their bikes not triggering it. Just put your heel down where you can see the markers and it'll trigger. I haven't been able to find the product unfortunately though - I'd love to upgrade my boots with them.

But, it's the same thing here in Idaho - if a red light doesn't change for you and you're clear, treat it like a yield sign. On a similar note - a bicycle in Idaho isn't required to stop at a stop sign, only yield. It really makes country blocks fly by when you don't have to come to a dead stop every mile.
 

machiasmort

New Member
Aug 10, 2008
91
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Buffalo,NY
I keep a rare earth magnet on my bike for when that happens. Really, only two situations call for it. One is if I'm by myself in the middle of the night and there's no cars anywhere, but my bike isn't ferrous enough to trip the magnetic sensor, so it stays red on me. The other is if I'm in the front of the line in a left turn lane - I've had it not trip for a whole line of cars before.

Someone told me they sell a spur like attachment for boots, as a lot of motorcycle riders even have this problem with their bikes not triggering it. Just put your heel down where you can see the markers and it'll trigger. I haven't been able to find the product unfortunately though - I'd love to upgrade my boots with them.

But, it's the same thing here in Idaho - if a red light doesn't change for you and you're clear, treat it like a yield sign. On a similar note - a bicycle in Idaho isn't required to stop at a stop sign, only yield. It really makes country blocks fly by when you don't have to come to a dead stop every mile.
Your 100% right! I seen the thread and was about to enlighten everybody!!! I set up a pair of sneakers like that!!! Rare earth are the kind that will even pull a filling out!!! I used that and some black epoxy!
 

deacon

minor bike philosopher
Jan 15, 2008
8,114
9
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north carolina
There is one set of lights on my way to the mall to walk. I know from experience that I can sit there for a week and not trip that light. If the straight lane is go and there is nothing coming, I am so out of there I don't even slow down. I'm sure one day they will have me in front of a judge, but until then, I'm gonna run that muttha
 

Atomicdog

New Member
Feb 9, 2011
21
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Ca
Im sorry but the whole metal detector theory is wrong folks.

Ive installed thousands of these detectors, its a electrical feild created by the loop, A coil of wire that creates a feild witch is broken when a vehicle stops on top of the "detector loop" weight metal ect.... has nothing to do with it.
Some intersection are equiped with camera detection instead.Not all cameras are "Big brother watching YOU".

If the light doesnt turn best option if available is the cross walk button .
The ped button rules in most case's because ada requirements,It all depends on how your city programs the controler.

Or just get the right freq strobelight and mout it and never miss a green "EVER" (not recomended for obvious reasons).
 

GearNut

Active Member
Aug 19, 2009
5,104
11
38
San Diego, Kaliforgnia
I zip-tyed a magnet out of a computer hard drive to my left pedal. I just keep that pedal down when I coast over the sensors in the road. Works like a charm.
 

GearNut

Active Member
Aug 19, 2009
5,104
11
38
San Diego, Kaliforgnia
You will have to get used to the pedal sitting funny when it is at rest with your foot off of it. The weight of the magnet causes it to always come to rest with the magnet at the bottom.
DuctTapedGoat, you can install 3 magnets if you want to, but one is really all that you need.
 

GearNut

Active Member
Aug 19, 2009
5,104
11
38
San Diego, Kaliforgnia
You must have a really, really low lowrider!
I have found that the effective range of the magnet averages 1 foot above the pavement max. Even at that height it will not trigger all the lights. 3 inches above the pavement (the distance between my pedal and the ground) seems to trigger all of them for me. Of course, getting closer to the pavement/ sensor is even better.
 

DuctTapedGoat

Active Member
Dec 20, 2010
1,179
10
38
38
Nampa Idaho
You will have to get used to the pedal sitting funny when it is at rest with your foot off of it. The weight of the magnet causes it to always come to rest with the magnet at the bottom.
DuctTapedGoat, you can install 3 magnets if you want to, but one is really all that you need.
Well, one on each pedal means I wouldn't have to worry about what foot I leave on the pedal when I'm standing. I have loads of dead hard drives too from doing computer repair the last few years.
 

GearNut

Active Member
Aug 19, 2009
5,104
11
38
San Diego, Kaliforgnia
Well I understand then! You have a surplus of them. I buy the magnets at $6 each from a local electronics surplus store. I have them on my motorcycles too.
 

Norvegicus

New Member
May 8, 2011
5
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illinois
Hi, this is my first post and thought I'd throw in some illumination. An electric loop is how metal detectors work too. A little rusty on the physics semantics here, but an electric current in a coil of wire generates a magnetic field with a certain amount of flux. DC makes a constant field, and AC a changing one. Whenever the flux of a coil like that changes the current also changes in the wire, and a changing current also makes a changing flux. If an electrically conductive material enters that magnetic field, the magnetic field generates small circular currents(eddy currents) in the material (like an electrical generator) that have their own magnetic fields that interact with the current flowing through the wire loop, increasing or decreasing it. A sensor detects this disturbance and registers it as a vehicle. Metal detectors work on the same principle, but I think they use an oscillating current and circuitry to cause a field that can identify between different sized and composed metals based upon their electrical and magnetic properties relative to that resonating field. Course, a strong magnet skips the eddy current business and messes with the field directly. I wonder how it sounds on a metal detector...Yup, my metal detector reacts very strongly to a couple of rare earth magnets I brought it near. That could be that they have metal in them, but I'd say it was the huge mag field they have as a steel bolt of comparable mass and size had less effect by far.
 
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steampunk

Member
Mar 10, 2011
440
0
16
lakewood co
nice...we have this issue in denver too...looks like a rare earth magnet to slip in a shoe is the way to go or maybe make a pocket on a ankle strap...ya know the one to keep your pants out of your chain....
 

The_Aleman

Active Member
Jul 31, 2008
2,653
4
38
el People's Republik de Kalifornistan
Over the years, I've seen some traffic lights in some small towns run off a timer during certain hours. Neither vehicle nor ped button will make them change. Sometimes small-town cops know this, too, and might watch the intersection. Ride slowly and carry big flashers at night :D
 

biknut

Well-Known Member
Sep 28, 2010
6,653
475
83
Dallas
I give every light the benefit of doubt, but I only have the patience of a chopping block. One chance and then off with it's head.

Any light that doesn't change I consider to be malfunctioning, and then treat it as a stop sign.