Traffic Light Sensors

Joined
Feb 25, 2013
Messages
72
Location
Jacksonville, FL
Bike
WR250R/KTM 890/KTM690
This article summarizes testing done to determine how a motorcycle can trigger an inductive loop traffic light sensor.
Apparently the magnet under the frame works.

 
Since the triggers are just in effect, metal detectors pointing upwards the key is to get the most metal over the detector as possible. If I can see the cuts where the wires were laid (you cant always see them, sometimes they pave over them without cutting new grooves) then I stop the bike over the edge of the wires, trying to be directly over as much of the wires as possible. Pretty much always works. As long as you can see where the wires are.
 
Since the triggers are just in effect, metal detectors pointing upwards the key is to get the most metal over the detector as possible. If I can see the cuts where the wires were laid (you cant always see them, sometimes they pave over them without cutting new grooves) then I stop the bike over the edge of the wires, trying to be directly over as much of the wires as possible. Pretty much always works. As long as you can see where the wires are.
Exactly ! And if you cannot see the wire cuts, and there is a White Stop bar painted on the road, stop just behind it, center of the lane. When I can see the cuts, I pull on the section to the left or the right where more wire will be under the bike. In our area they are now using the camera sensors mounted up with the stop lights. Those seem to work well when in the center of the lane. These methods have seldom not worked for me.
 
Contrary to popular belief, the bike needs to be in the center of the detector loop. Sometimes there's a bicycle painted in the center of the detector. This is where most oil and debris accumulate, not the most desirable location for a motorcycle to be at. However, the signals will usually detect a motorcycle, only if the detectors sensitively is adjusted correctly. No light detector can detect my dual sport, probably due to the high ground clearance and the smaller crosssection.

Here in California, there is a law that states if the wait is longer then 2 minutes while on a motorcycle while at a signal. Then the rider can proceed through a controlled intersection when it safe to do so.

I also installed a couple of high powered Nyodedium magnets on my a few of my bikes. The magnets did not improve traffic signal responses during the time had them installed. I found that I have to clean the magnets often to remove black iron dust and debris picked up from the roadway.
 
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I put a magnet specifically sold to trip the sensors on my '82 GL500I, never did a thing. Only stopping correctly over the coils did. It surprises me how many people who ride motorcycles believe that there is weight sensor under the cutouts, like a scale or something.
 
There aren't any traffic lights in the county where I live. Not much of a problem for me.

But in Duluth and Superior you pretty much have to position your motorcycle where there are no potholes at the intersection. That's life in the north-lane.
 
I think the magnets are more of a placebo if anything. The local DOT really needs to adjust sensitivity of trouble intersections, but they need prompting to do so. But with so few % of vehicles being motorcycles, I doubt there's usually enough complaining voices to have a change made.

I live in a state with a safe-on-red law, but there's been some trouble intersections where I don't feel safe exercising the right to proceed after the required wait. It's rare a car doesn't show up to trigger at these intersections, but on occasion I'll instead make a right turn followed by a U-turn at the next available opening.
 
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