Becky, that sounds totally bogus to me.... many of our intersections even have a little "T" painted on the optimal place to put your bike to change the signal... and you can contact the DOT if a light won't trigger - they actually do come and re-calibrate the device to pick you up. Even my CF bike has enough metal (rims, spokes, cranks/chainrings on mine) to be "seen" by a properly set up signal.