The car Bibles product reviews: Signal Sorcerer traffic light changer.
Product Reviews
Signal Sorcerer traffic light changer
Tested September 2006 
Website: www.signalsorcerer.com
There are plenty of devices and gizmos out there designed to entice the impatient driver with the allure of forcing traffic lights to be green in their favour. They fall into two categories. In the first and illegal category, there are devices like infra red blasters and emergency vehicle transmitters. These both work on the same principle - either an infrared or a radio signal is sent out from the vehicle. Traffic lights at the next junction will receive the signal and force the current cycle to drop into emergency mode where all the lights are changed to red except for those for the approaching vehicle. System designers assume these vehicles to be emergency vehicles, and facilitating their progress by stopping all traffic at a junction is A Good Thing. But not all devices are on emergency vehicles; they've started to find their way into the consumer world. They're expensive, they're illegal and expect to go to jail if you're caught with one.
Fortunately for all of us, the Signal Sorcerer falls into the second, legal category of traffic-light changers. To understand how the Signal Sorcerer works, you need to understand how traffic lights work. Generally speaking, they are either controlled from a central control centre, or more often, local control boxes (the little grey box at every junction). Depending on the time of day, the lights will operate in a fixed pattern designed to allow the maximum flow of traffic. For the less-used paths through the junction, inductive loops are buried in the road. These are loops with a weak electric current in them which generate a magnetic field. When a car passes over them, the field is disturbed and the traffic lights "know" a vehicle is now waiting in that lane. Typically, this is a left-turn lane, or if you're in England, a right-turn lane. When the traffic lights detect the presence of a vehicle, the cycle changes to allow a green light for that lane, thus allowing you, the hapless driver, to turn across the junction. The principle is sound, and it works really well. Sort of. To paraphrase George Orwell, "All vehicles are created equal but some are more equal than others". You see the problem is that inductive loops work exceptionally well when hulking great chunks of steel drive over them. Like cars built in the 80's, trucks, buses and so on. Even today, the buzzing, noisy lump of pollution in the front of a car (the engine) has enough steel in it for these inductive loops to work. The problem is motorbikes and ultra-modern sports cars, and to some extent, newer sedans. There's a lot of aluminium in these things now and less and less steel. This is especially true on motorbikes - essentially a collection of plastic, carbon fibre and aluminium. This presents a problem. The traffic light's inductive loop often doesn't pick up motorbikes. I ride a motorbike, I know. There are some junctions around where I live that never detect my bike. I have to sit there like an idiot staring at a red light waiting for a car to come along behind me and trip the cycle of lights. Worse, if it's late and there is no other traffic around, I have to shoot a red light, or do a bizarre series of right turns and u-turns to get where I want to be. It's bloody ridiculous, and anyone who rides a motorbike will bear me out on these experiences.
So it was with keen interest that I received a Signal Sorcerer for review. Their website is flashy and has tantalising claims about all your greenlight dreams coming true for $20. I read up on the device and the theory seemed sound enough so I decided to give it a go. Basically, the Signal Sorcerer is a really strong magnet housed in a weatherproof plastic case. The idea is simple. If you attach it to the bottom of your vehicle - in my case my motorbike - and drive over an inductive loop, the strong magnetic field is enough to disrupt the inductive loop into registering your presence. Sort of like Darth Vader and the old "sensing Luke" trick, only with magnets. The idea, then, is that it gives you the presence that your bike is missing, and so rather than sitting there waiting at the endless red light, you'll trip the system and a green light will be forthcoming in due course. And on you go.
The packaging is pretty simple - a plastic tube with a paper instructional insert, the magnet, two alcohol swabs and a zip-tie. The instructions are straightforward; clean the area where you're going to put the Signal Sorcerer with the alcohol swabs, peel off the protective backing from the sticky stuff and stick it in place. The zip-tie is there for added security to back up the sticky stuff. The idea is sound, and on most motorbikes I can imagine it works well. The ideal place to stick this thing is on a lower frame rail, as close to the road as possible. My problem was that my bike has skidplates on the bottom - aluminium ones at that. The magnet had nothing to stick to so I was reliant on the sticky stuff to hold it in place. No matter, I cleaned off the only place I had available - the bottom of the centrestand - peeled off the protective backing and stuck the unit in place. I secured it with two zip-ties just to be sure. You can see it nestled under my centrestand, stuck to the skidplate in this photo:
The road test
At the risk of boring you stupid, I'll mention one junction that's my favourite for staring at a red light. This will mean nothing to you unless you live in Salt Lake City and own a motorbike, but westbound Bangerter Highway turning left on to southbound Redwood road. I have gone through that left turn light on red more times than I can remember. Without fail, it never sees my bike. Seemed to me to be the best place to give the Signal Sorcerer its first test. I cruised to a stop at the front of the line with no traffic behind me and waited to s.....what the? A green arrow? Fumble the clutch, crunch, stall the bike. It was so unexpected I muffed it. One quick recovery later and I was off. Well that was an excellent start. I looped around and back and did it again. Again, a green arrow as the cycle came up. Wow! The rest of my roadtest was basically much the same. I found all the lights that never normally see me, and they all tripped their cycles and gave me a green light in due course. I was duly impressed. I did my road test more of less in the dead of night to ensure I was the only vehicle around. That way I wasn't ever in a situation where a car came up behind me and tripped the light sequence.
What Signal Sorcerer won't do. If you buy one of these expecting to cruise up to a red light and have it magically turn green, you'll be disappointed. That's not what it does. It merely ensures your vehicle is seen by the traffic light inductive loop, so that the signal order will be tripped to include your lane in the next cycle.
Where Signal Sorcerer won't work. Not all traffic lights use inductive loops to detect traffic. Some work on reflected light detection and others are simply run off timers with no way of influencing them. You'll know if you've found a timer-driven light. You'll be sitting at a totally empty junction in the dead of night for 5 minutes at a red light with no other traffic. The picture on the right shows a typical inductive loop setup - they're buried in the road surface and the cuts are filled in with hot tar giving a tell-tale rectangle or circle 'drawn' on the road on the runup to the lights.
Conclusion - it works.
If you've had problems with your motorbike or lightweight sports car, or even your sedan not being detected by inductive loop traffic light systems, this certainly seems to do the trick. Don't buy one expecting miracles, but go in with the knowledge that you'll stand a far better chance of being an 'equal' at the traffic light grand prix next time.
Update - 2009
It looks like Iron Horse industries have gone out of business, and the Signal Sorcerer is more and more difficult to get hold of. A potential replacement for it is the Green Light Trigger or the Red Light Changer, one of which I hope to be able to review soon.