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  1. #1
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    3 bicyclists = 1 car ... at least as far as a traffic light concerns

    On my commute home, there is a left-turn traffic light that does not give a .... for two-wheelers. Usually, I wait for a minute or two for a random car that turn left. If no luck, I do a usual shpil: left on a crosswalk and right over the road to the right side.

    Today, two bicyclists pooling behind me, and no cars turning left with us. While we are waiting, I am saying to my accidental partners:

    "this !@#$ does not give us enough respect, only turns a left arrow for the cars".

    To my surprise, the light (as if overheard me) turns the left arrow green. Wow... power to the people!

  2. #2
    Subjectively Insane MilitantPotato's Avatar
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    Position is key on those damned things, normally. You can legally run them if they don't turn for you, how long you need to wait depends on local laws though.

    Call your local DOT, they might have info on where to sit to trigger it, having a steel bike helps.
    You've got a bike, so you gotta move.

  3. #3
    Senior Member
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    Quote Originally Posted by MilitantPotato View Post
    Position is key on those damned things, normally. You can legally run them if they don't turn for you, how long you need to wait depends on local laws though.

    Call your local DOT, they might have info on where to sit to trigger it, having a steel bike helps.
    More importantly, the sensitivity is adjustable and they should be willing to come out and turn it up enough to detect your bike. The most commonly used detectors are inductive loop sensors which will detect any metal objects (Fe, Al, Ti should all work fine, but CF isn't as good a conductor). On bicycles the parts that are usually detected best are the aluminum rims since they're closest to the road surface. Where the sensors are marginal I find that laying the bike down can help to trigger them. If the road hasn't been resurfaced you can see the cuts in the pavement to position your bike over the sensor. If it has been resurfaced then usually putting the bike near the middle of the lane and just behind the stop line will be over the sensor.

    Note that Caltrans has just come out with a new policy directive calling for all new and upgraded traffic sensors to properly detect bicycles and motorcycles - it becomes effective next week. Although it doesn't directly address existing traffic signal sensors, it might encourage the local DOTs to be more responsive to concerns of cyclists and do a better job of adjusting the sensitivities.
    Last edited by prathmann; 09-02-09 at 01:50 AM.

  4. #4
    Seņior Member ItsJustMe's Avatar
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    Here's the standard reference for this:
    http://www.humantransport.org/bicycl...nals/green.htm

    This has always worked for me, but if this doesn't work, try lying your bike down at a low angle with a wheel over the sensor. One traffic engineer said that a bike wheel laid down near the ground actually generates a larger signal than a car.

    To head these off; magnets probably don't work, and it doesn't matter what your bike is made out of as long as it's a good conducgtor (as prathmann says above).
    Work: the 8 hours that separates bike rides.

  5. #5
    RacingBear UmneyDurak's Avatar
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    Quote Originally Posted by olegb View Post
    On my commute home, there is a left-turn traffic light that does not give a .... for two-wheelers. Usually, I wait for a minute or two for a random car that turn left. If no luck, I do a usual shpil: left on a crosswalk and right over the road to the right side.

    Today, two bicyclists pooling behind me, and no cars turning left with us. While we are waiting, I am saying to my accidental partners:

    "this !@#$ does not give us enough respect, only turns a left arrow for the cars".

    To my surprise, the light (as if overheard me) turns the left arrow green. Wow... power to the people!
    You can also legally treat it as a broken light and make a left turn when it is safe....

    UD
    I see hills.... Bring them on!!!
    Stay calm and bring a towel.

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