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Getting detected at traffic signals
Johan van Tol
4/2/2018 11:02 PM
Cyclists tend to get blamed a lot for running red lights. Sometimes rightly so. Cyclists are vehicles and should follow the rules of the road like motorized vehicles. But on the other hand cyclists can pose the question "Why should I care about traffic lights, if traffic lights don't care for me?". It is sometimes quite frustrating waiting for a red light that never seems to want to turn green. Sometimes traffic from the opposite site get a green, but your light stays red, and then the cross traffic gets the green again. Ahhh....
The reason is that many signalized intersection use detection loops in the asphalt to detect waiting vehicles at the light. While they are efficient to detect the abundant steel of cars, they are less efficient in detecting bicycles. However, they are (should be) able to detect bicycles, if the sensitivity is set correctly, and bicycles are lined up in the "sweet spot" which in some cases is only an inch wide. In Tallahassee there are typically 2 styles that are used. The most common one is a rectangular loop (dipolar), with a sweet spot just to in inside of the right or the left wire. The second type is the quadrupolar loop, which is like a figure 8. There the sweet spot is right on the center line, and is the preferred option for cyclists, as it is more sensitive and places the cyclists right in the center of the lane.
So that is where you should be as a cyclists, and it should work if you have steel or aluminum rims. If it does not turn the light, complain.
And then there are cases where you have no idea where the detection loop is, because the road has been repaved, or there are three different loops in the old pavement, and you have no idea which one is active. Well, there's a sign for that, a road stencil and an accompanying sign to help cyclists position themselves to get the light to turn green. However, for some reason our city has been reluctant to implement that. We, as cyclists should ask them to do so.
While this issue has been brought up to city staff repeatedly, nothing has happened. So, we'd like to ask you to complain. If you have a traffic light that does not detect you on your bike, complain. The best place is to go to DigiTally, proviing the location of the light that does not detect your presence. You can refer them to the NACTO (National Association of City Transportation Officials) guidelines. Without your help nothing will happen, so complain, and complain again !
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