Triggering Traffic Light Detectors

Disruptions in the magnetic flux by the metals in the vehicle.

Don't know where you are that you are having a problem but the one on our plants automatic gate picks up motorcycles just fine.

I'm right with you on the frustration factor. Fortunately it rarely happens on my normal work commute or on my usual fun routes, but I have had it happen at other times. And I've heard many, many others complain about it.

I assume you've heard of putting some neodymium magnets under your motorcycle, yes? Supposedly this gives you enough extra magnetic "oomph" that you'll trigger the light. You can find them for sale in biker catalogs or order them through a variety of other sources. I don't know if it works - none of my riding pals have ever tried them either - but it seems worth a shot. Here's a like to a video that seems cheerfully optimistic:

http://www.metacafe.com/watch/828731/trigger_green_traffic_lights/

I have had this problem in the past. I now have a strong magnet at the bottom rear of my front fender. I stop the bike so that the rear of the fender is over the road sensor. No more problems. Most bike shops in my area sell these magnets. Just get one and put it on the lowest part of your bike. Then stop your bike with the magnet as close to the road sensor as possible.

I don't think you can legally do that. I would start by complaining to PENDOT and see if you can scout out other motorcycle clubs that have members that have that problem.

It may be that you are finding a number of lights that do not have the correct vehicle sensitivity and they should be fixed if they don't meet spec.

I think the problem is PENDOT's (or the local community that owns them) and you shouldn't have to spend a dime to have the problem fixed (you already paid the taxes).

By the way, I used to live just down the road from you in Spring City, PA.

Hello Rachel

Ozzb: said Don't know where you are that you are having a problem but the one on our plants automatic gate picks up motorcycles just fine

I figure on killing two birds with one stone here. A more pertinent question is where Ozzb is located, nobody in California knows how to install the road sensors, possibly a look at a working example would help them.

I've been riding motorcycles for over 30 years now, and the odds haven't changed much, a little better than even money that a motorcycle will trip the sensor.
Caltrans engineers are diabolical . Some left turn lanes feature multiple sensors, and will apparently skip a cycle if there's only one vehicle in the lane. So you never know whether the light is malfunctioning or not.

Besides running the light, a technique that sometimes works is to approach the sensor as diagonally as possible. This puts a little more metal over the sensor, the best I can say is sometimes the magic works, sometimes it doesn't.

A caveat to that is this maneuver leaves you in a bad position for rapid acceleration through the intersection. Repeating a phrase that has already been used. I don't know where you're at, around here as soon as you move the motorcycle to a diagonal position , this guy called Murphy usually appears from nowhere, slides up behind you, trips the sensor, and lays on the horn.

PS. Let me know if you come up with something, I may be your first customer.

Road runner gave part of the answer. Some traffic controllers are set to not trigger on one vehicle. It has to count TWO vehicles.

Solution; back up behind the sensor coil and then drive through again. Now light triggers.

Back when I was young and foolish; a favourite trick to shake a tailer was to cut the corner and drive up the wrong lane thus triggering the coil and giving your tail a red light to run. If they didn't have balls they stopped. <grin> and lost! Then the cops got smart and had the controller's counter reset to need two counts (vehicles) to trigger the light. Grrr!

Try it.!

Hello elnav

I'm glad to know I'm not crazy. I thought those left-hand turn lanes were requiring two vehicles to trip.

Approaching the sensor diagonally works on the gate at my friend's condo.
I have seen some sensors that seem to be laid in a circular pattern (I told you Caltrans was diabolical) which makes the diagonal approach difficult to say the least!

I Google traffic loops sensors. Supposedly improvements are coming, a change in technology to say infrared. It also appears that big brother is going to be doing a little more watching.

• "Certain new detectors output vehicle inductive signature through a serial port on the detector card. These vehicle inductance patterns can be used to identify vehicles, measure travel times, classify vehicles and determine vehicle origins and destinations."
• I have thought about setting up a coil and a capacitor (like a polarized magnetic charger) and seeing how that affects the loops. My luck that EMP would fry the sensor and the ignition on the motorcycle, and I be stuck there all day. The tried and true method of waiting one cycle then running the light seems to be the best low-tech solution, and a good excuse for running red lights.
• PS. What are you doing on this thread? It's too blasted cold to be riding motorcycles in Canada this time of year. Stay warm Y. W.

Well then you need to get together as a group in your areas and have the issue looked in to. There are sensitivity adjustments on the controls. At one time there were some complaints about that around here. Most have been taken care of. Harley Davidson of Baltimore and the clubs take great effort to sponsor charitable events. I guess this has its benefits.

This may not be of much help in Pa but in California if the detector fails to respond to your vehicle after a couple of cycles you may proceed when it is safe to do so. Check out Pa law, it may be the same. Of course it is still annoying no matter how you look at it.

I try to slow way down before reaching the coil, then approach near one side, so more of my bike is close to the sensor.
Another old trick is to lower your sidestand over coil.

I also live in cali and both of the above mentioned posts are correct. What works for me is if I pull up to the sensors completely to one side, having the whole bike along one side of the sensor. You can see where they installed them and easily do this.

I am no expert on these issues. However, if the problem is to increase the magnetic permeability of the bike to the point where it exceeds a threshold, the permanent magnet technique would not work.

That same problem exists in small AM radios. The solution there is a small "flux sucker", a piece of ferrite. Ferrite is not expensive, is lighter than carrying around a VW engine block, and may help get you over the threshold of magnetic permeability.

Good Luck

I never heard of using magnets before this. In Indiana and Kentucky I have found it best to approach a left turn lane sensor on the extreme right side of the box. I have encountered this problem on with my Electraglide Classic. Not a small bike by comparison. I still have problems tripping sensors once and a while. I typically find myself avoiding traffic lights by taking alternate routes out of habit. That started back in the seventies when pressure plates were still being used.

When I was in university the gate and a traffic light to let out vehicles was also the one for bicycles. The bicycle never tripped the gate and light. Solution was to use a heavy chain for your bike lockup, then momentarily drag it across the sensor as you approached. It took a little practice but worked.

I just found this link. I don't know if the device works, I'm going to do a little more research.

For $24.95, I may try one, if it doesn't work, I can always sick the credit card company on them.

http://www.greenlightstuff.com/

Yeah, that looks like what I was planning on developing... just could never get enough information about how those things really worked...

sigh

thanks!

Rachel

Norristown, PA

My son uses a little magnetic device that he bought online to trip the light sensor. It attaches to the underside of the bike frame. He says it almost always works!

We can run a Rover on Mars by remote control, see golf balls from orbit and detect all kinds of objects electronically, but we can't do something as simple as control traffic lights. I don't think they want to because it would reduce revenues from traffic tickets and it would cost a bit to do it right.

drive in the middle of the lane it will work better for smaller vehicles

try to look for it in youtube, i saw it there

On the back of one of my MC club newsletters they had a product to remedy that problem. It was a heavy magnet that mounted below chassis and was supposed to trigger the embedded switches in the road. I have this problem crossing a highway leaving my home. Unless there is a car behind me i have to run a red light to cross it or ill sit there forever.

I have yet to test this product,but i have heard from a few people that it works.

One solution is to adopt the technique that the experienced push-cycle user adopts for safety: on approaching a set of lights and assuming one is not turning (UK & Eire) left and that it is safe to do so (a quick glance over the right shoulder will do...), track across into the centre of the lane and force a queue to develop behind. The cycle passes over the detection loop and, if it doesn't trigger the detector itself, a following road motor will do so instead.

Upon the lights clearing to green and it being safe to proceed, track back to the (UK & Eire) left side of the road upon clearing the junction to give faster traffic the opportunity to pass safely.