If you're a regular bicycle commuter, then you've no doubt experienced the following scenario: you're the only vehicle going in your direction at a controlled intersection, and the light is red, but it won't change to green because the traffic sensors embedded in the asphalt can't register your presence. Well, that's where the Veloloop comes in. It's designed to make those sensors think that your bike is a car.
Embedded "inductive loop" traffic sensors work by creating an electromagnetic field in the surface layer of the road. When a sufficiently-large metal object – such as a car – stops above the sensor, it creates eddy currents within that field. This is detected by the system's traffic signal controller, which causes the light to change.
Bicycles, however, simply don't consist of enough metal to trip the sensors. Approaches such as positioning your bike in exactly the right orientation relative to the sensors' looped electrical wires are claimed to work (as are magnets in the rider's shoes), but the Veloloop looks like it's considerably easier.
It remains in standby mode while the bike is in motion, but sets to work once an accompanying spoke-mounted magnet indicates that the rear wheel has stopped turning. Using its looped aluminum antenna, the Veloloop then starts by searching for the sensor's electromagnetic signal, scanning a variety of frequencies. Once it locates the signal and "locks on," it then emits its own signal. This affects the sensor's magnetic field in the same way as the metal in a car, triggering a traffic light change.
The Veloloop is powered by two AA batteries, and can reportedly run for at least a year on one pair. Its California-based creators are currently raising production funds, on Kickstarter. A pledge of US$99 will get you one, when and if they're ready to go.
More details are available in the pitch video below.