The loop in the road is an induction loop that registers the metal mass of a car by a change in current. This phases the lights.Your bike has less metal mass so it doesn't register.
I have a large, powerful magnet on one of the suspension dog-bones (close to the ground) that causes the induction loop to trip. I haven't had that long wait since I put it there.
As for going through the light, it would all depend on the cop who stops you. I used to do it by paddling myself forwards at one crossroads near me and having a good look that it was clear.
Pete
