Seriously, anything except a pedestrian should trigger the sensors. Car, motorcycle, bicycle, wheelchair, or a freight train from your subconscious trying to crush everything in its path... whatever it is, if it's sitting in front of an intersection and it's not on the sidewalk, chances are it's waiting for the green light!

Sure, you might get a false positive from time to time, but whatever causes the false positive probably shouldn't be in the car lane in the first place.

With sensitivities that low false positives are triggered by cars in other lanes. Induction loops are very sensitive to variations. Believe me, I spent many hours on tweaking detectors.