Total Motorcycle Community Forums

Traffic lights controlled by magnetic inductive loop detectors started being made in the mid 1970's, and there have been several generations of the technology since then. There are lots of 'em here in southern New Jersey. The more modern ones are supposed to be more sensitive to motorcycles.

ofblong wrote: hmm odd cause when I took drivers ed 12 years ago they said if you are on a moto and stop at one of these lights your moto might not weigh enough to trip the sensor. They never said anything about metalic that it had to do with weight. Maybe thats just in michigan? or it could be it was what they started with and then changed to magnetic reading?

I've heard the "weight detector" explanation, but have never found a city traffic engineer that's ever seen one. What is most common is what they call a sensing loop. This is basically a rectangle of wire embedded in the road that is nothing more than a large metal detector. As with most metal detectors, they only pick up ferrous metals (iron, steel, etc...), which motorcycles do not have a lot of (compared to a car).

Sensitivity can be easily changed, just like you can on a metal detector. The problem for traffic engineers is that the threshold of sensitivity that will recognize the fairly low ferrous metal content of a motorcycle, is also the level that will trigger a false signal from a large car or truck in the next lane. It's a careful balancing act. It can be done if the city traffic dept. cares to spend the time to do it right. Many don't. Preferring to pretend that motorcycles just don't exist.

I get stuck at some of the lights on my way home at work...especially with the ring sensors on the ground. I have tried the sidestand trick, the starting your bike trick, throwing rocks at the light trick, everything. I usually have to go straight and turn into a shopping center, then come back around. some lights just suck "O Ring" and no matter how long you sit, you won't move unless a cage comes behind ya.