Instructables
Picture of Trigger GREEN Traffic Lights
if you or someone you know, owns a motorcycle, a scooter or even a small car, you've probably noticed that it's easy to get stuck at traffic lights. Well, I'm going to explain why it happens and show you a great little trick that will save time, gas and frustration by getting you a green light every time.


 
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Step 1: The Problem...

Picture of The Problem...
At most traffic lights and turn signals, you will notice a loop of wire buried in the pavement of the road near the stop line. This is called an Inductive-loop traffic detector that operates by sensing a change in frequency to the electromagnetic field over the coil of wire. In other words, when a car pulls up, it senses the vehicle and the light changes. Most motorcycles, scooters, bicycles and small cars don't have enough conductive material to trigger these loops and change the traffic light.

Step 2: The Solution...

Picture of The Solution...
Produce a very powerful field that increases the inductance in these traffic sensors, and causes the light to change! Here's how to do it...

Step 3: What you need!

Picture of What you need!
2 Neodymium magnets. I chose two from CMS Magnetics that have a pulling force of over 6lbs each. I also bought a roll of heavy duty exterior mounting tape.

Step 4: Attach it...

Picture of Attach it...
After cutting off a small strip of tape, I attached it the magnets. Then I applied it to the bottom of our test scooter, perpendicular to the road.

Step 5: Optional step & Video

Picture of Optional step & Video
Because magnets rust, I put them stacked together inside a waterproof, rust-proof, pill holder or Bison Tube and then stuck this to the bottom of the scooter. Should last a long, long time! Now here is the video!



You can learn more about how this works Here

crazyg3 years ago
cool, so i guess revving the nuts of your motor at the lights does the magneticy thing thus changing light,
In Wisconsin this is no longer a problem, as in 2010 we got a new law that allows bikes to wait and proceed through the red if traffic allows. I used to report all the lights that did not work, but now I don't bother. I just ride through.
cbennett8115 years ago
would this also work at the drive through windows? most of the time when i pull up to the speaker they cant see me. so i always have to pull around to the pay window then they get all confused and probably spit in my food! it would b awesome if it works in the drivethru, but i think wendys still uses the scales. let me know if anyone has a tip for that.
If you ever find that they have spit in your food, you sue them for lots and lots of money. LOTS.
i always thought that the lights here were done by weight. i may be wrong. anyone know? i live in auckland new zealand
I thought they were done by weight, but maybe they've upgraded while I wasn't watching... I'll have to have a closer look at the next intersection I mosey past.
I did too, as it changes a bit faster when you pull on the line. I live in the US of A.
Installing a scale under the street costs far more money than running a loop of wire and then ignoring it until it is in that perfect state of maladjustment where nothing smaller than a medium car will trip it. So even though it's always the lighter vehicles that don't trip the loop system, it isn't actually by weight, it's by metal content.
abquid Rishnai6 years ago
In the old days a lot of lights used a metal plate that was weight-sensitive; you can still see some of them around. But they've been almost entirely replaced by the wire/sensor type.
Rishnai abquid6 years ago
Excellent point. I probably should have said "installing a scale nowadays costs more than the wire/sensor type." Modern technology has changed quite a bit, and I don't know of any old-school ones remaining in Colroado. Of course, if someone finds one, I'm willing to ride several hours to go look at it...
msmythers4 years ago
In our area in Florida they have to cameras. The cameras don't detect motion, they are inferred and detect heat from the car. I'm waiting for days when the temperature is over 100 to see how that works.
annaliesa!4 years ago
why not put the niobiums on the bottom of your shoe? Then you could put your foot down on the line when you want to let the light know you are a vehicle waiting for your turn? Just a thought, its still early and this post is very old (2008) so never the mind. :P
aurical4 years ago
Nice instructable! I think in North Carolina (RTP area) they a mixture of induction and motion sensors. I commute by bicycle and I've noticed that certain lights seem to change without cars to trip the light. At first I thought I just got lucky, but it happens regularly a few lights in my neighborhood (where there are a lot of bicylists). Unfortunately they aren't very common and I've been thinking about getting magnets for my bike.
Ashinka5 years ago
At the end he says "Save time, gas and Frustration" How can you save Frustration? Other than that This works, I did it to my Dads bike, but My Magnets are rusted up because I count find any rust proof casing.
attilam6 years ago
The other thing you can do on a motorbike or scooter is turn the engine off, then use the starter motor. The field of the magnets in the motor will fluctuate as it spins, and it can be enough to trigger the system...
bugman14707 years ago
Another way to trigger the traffic signals for you fellow bikers out there, When you come up to a ground loop, put your kickstand down on top of where the wire is. This will disturb the magnetic field and start the timer to change the light. Safe Biking! Steve
I'm not sure that this works-I've been at some lights, leaned the kickstand down on the sensor/wire and still no luck. Of course, the sensor could have been broken. There's one light in particular where the kickstand never works--I'm going to try the magnet trick and see if that gets it to change...
And then remember to put it back up when the light changes!
I think what actually trips the sensor in this case is tilting your bike frame - you don't need a kickstand at all. As I understand it, the sensor coils send a current pulse which induces a current in any conducting loop above the sensor and *oriented horizontally*. The induced current then produces a field of its own, which induces a current back in the sensor coil, and that's how it senses. A bike frame looks like a vertical conducting loop, relatively speaking, so tilting it over makes it horizontal enough that it can interact with the sensor. It's the (projected) area of the loop in the plane of the sensor/road that matters, i.e. the area you'd see enclosed if you were to look at the shadow cast by the bike from an overhead light source. This area goes from nearly zero for an upright bike to big enough to be measured if you tilt your bike frame over by 20 degrees or so.
BEAST146 years ago
Is this legal? And would it work on a full sized truck?
The frequency that changes the lights is 14Hz. Most lights in major cities though are setting up encryption on the lights since people would go out an buy a MIRT device and change the lights themselves. Using these systems is illegal if you are not approved. Therefore I am only posting this information for discussion and spread of knowledge, not for it to be abused.
TCPMeta7 years ago
Nice little trick. Theres also another way to get a instant green with out waiting for the timer. A lot of citys that haven't converted to use LEDs instead of bulbs can be tricked or in heavy traffic areas. Emergency vehicles use a type of light signal that has a range of 25 to 50 yards and will make a red light turn green. This can be copied using a strobe light but you have to find the right timing for the light.
Dubi01 TCPMeta6 years ago
the emergency vehicles use a special strobe that is unique in strobing frequency and temperature. Different states use different specs. Off the shelf strobes don't work in 90% of the states, and as usual, it is illegal to use such devices by anyone but emergency vehicles (ambulance and fire engines), not even police cars are allowed to use these devices.
Slammer TCPMeta6 years ago
It's called Opticom and its marketed by 3M. A cabinet is attached to the light controller and it logs preemption requests. Although 3M will tell you that its impossible to reproduce their emitters (had an argument at a trade show with a 3M guy) it is quite simple to do. Opticom works with both traditional and LED traffic lights. That said, the request is logged, and you will be caught if you try it. Depending on where you are, you will likely lose your license so its not worth it.
This has nothing to do with Opticom or any other method of "activating green"... this is simply increasing the footprint of the scooter/cycle etc.. by using magnets to trigger the induction loops' normal process when a car is present. The IR systems like Opticom can be triggered using an IR transmitter like emergency vehicles have (not all); however using the IR transmitters are highly illegal...not just loosing your license, but federal fines and possible prison. That said, search the web, there's sites that have information on how to use a specific type of IR remote control (TV) and key combo to trigger the IR sensors :)
TCPMeta Slammer6 years ago
You'll only get caught if theres a cop near by or if the light has a camera witch in the city of Jacksonville doesn't have due to some privacy act. Nine times out of 10 there isn't a cop around and it comes in handy is you own the same type of vehicle the police use.
shes a witch!
cyber_meat6 years ago
you can also do it a different way using a universal remote.
l)eM()N6 years ago
thought of a funny idea lol drop a msgnet on top of cement where the wire is
Hockeyhero46 years ago
Sweet, Since Gas prices are rising I recommend this for Motorcycle Lovers!!
wasgij6 years ago
i think thats illegal in Australia
swtmama6 years ago
I'm not a tech but I was told by a highway patrol if you just flash your highbeams at the light as you approach the light will change. I haven't tried it on my scooter yet, I'm just learning and still working on a good balance (lol, but it works in my car. I passed it on to a school bus driver that was getting delayed by a country stop light and she said it works great for her. I'll have to try the magnet on my scooter! Thanks! V
G33k6 years ago
you can get those magnets in a hard drive, but keep them apart though, once they stick together it's going to be hard to split them!!!
Tierra7 years ago
Awesome, I ride my bike everywhere and this would be sweet to use to not get all stuck at the lights waiting for a car to come and save me.
Ayce7 years ago
Thank you for the instructable I'll have to try this. And thank you bugman1470 until I get some magnets I'll have to try what you mentioned.