Every time the City of Encinitas adds or replaces a traffic signal loop detector, the new one is a CalTrans type D inductive loop, which CAN be sensitized to detect bicycles. Whenever I have trouble activating a traffic signal, I send an email to our city traffic engineer, and get satisfactory results about half the time. We are fighting a much tougher battle to try to get the city and state highway departments to mark the sweet spots of the detectors, perhaps with little bicycle symbols.