Monday, December 15, 2008
Psssh, It Triggers The Traffic Loop Sensor...As I Suspected
Check out this article from WIRED
"Getting stuck at a red light that won't change sucks.
It's even worse when you're on a bicycle because you'll never see green until a car rolls up and trips the sensor. That's never seemed fair to Ed Richley, so he's invented a gadget that tricks red lights into turning green. "About 10 years ago, when I lived in California, a colleague told me about a particularly obstinate (light) on his commute, and asked me to build something to force a detection," Richley told WIRED.com. What he's built is a gadget he calls a Traffic Loop Sensor Activator, and it does exactly what the name suggests — it trips the sensor that tells signal lights traffic is waiting. The bike commuter and engineer from Maryland has patented (.pdf) the device and is looking for someone to mass produce it. It doesn't look like much — in fact, it's pretty clunky, and the gram-conscious crowd will recoil in horror at its size — but Richley swears it works. Traffic loop sensors embedded in intersections are the bane of cyclists and motorcyclists everywhere because two-wheelers lack the mass needed to trigger the inductive sensors. A lot of cyclists resort to using magnets to do the job, but Richley says he hasn't seen any scientific evidence suggesting that actually works. So what makes his solution better? Like Ahab pursuing his white whale, Richley spent a decade lugging an oscilloscope to intersections, measuring the signal voltages to determine what kind of signal the loop sensors used. He discovered that they vary, "so I came up with a technique that scans for frequency and accommodates the pulsed mode of modern sensors," Richley told us. Push a button and Richley's gadget creates a brief, but strong, magnetic field that simulates the presence of a much larger conductor — say, the body of a car — and triggers the inductive sensor that lets the light know a vehicle is waiting. Richley says it works, and you can get more info about how here. But is it legal? “I've asked traffic departments about this and they universally think it's a great idea,” Richley says. He noted that in some states, including Maryland, the law prohibits “interfering” with traffic signals. So the question is, does his gadget interfere? Richley says it doesn't, and we're inclined to agree. It doesn't interfere, it, um, helps. And if radar detectors are generally legal… Besides, anyone who's been stuck at a red light for more than, say, two minutes knows the natural reaction is to just run it. We’d argue Richley's gadget promotes respect for the law. Richley notes that the problem he's solved is so ubiquitous that some states are exploring legislative solutions to what could be considered an engineering flaw. South Carolina passed a controversial law this year that allows drivers of motorcycles, mopeds and bikes to run any red after waiting two minutes or more. But in most states, all you can do at an endless red is wait. So far Richley's gadget is nothing more than a prototype. He's trying to line up partners to manufacture it, so it's anyone's guess how long it'll be before you can get one."