Originally Posted by prathmann

Loop detectors work with any electrical conductor - aluminum works fine and almost all bikes still have aluminum brake tracks. In fact some of the folks who come out to adjust the sensitivity of the detectors after complaints are made by cyclists just bring a single rim and lay it over the detector area. It's easier than for them to bring out a whole bicycle and gives similar results.

Locally the town south of us is experimenting with a microwave detection system that detects bicycles separately from other vehicles. That way the traffic lights can be adjusted to give cyclists enough time to clear the intersection when they are present but to have a shorter interval when there are no cyclists.