[Traffic Signals] Add button to cancel pedestrian/cyclist request and improve bike detection

I grew up in Winnipeg, where I learned to not let a machine to tell me it's safe to proceed. Cycling in Vancouver, the experience I often have, is I arrive at an intersection, press the Beg Button, wait for traffic to clear, then proceed through the intersection when there's Nobody Not a Soul Around. Then I hear the boop-boop behind me of the light having changed, making cars on the arterial road stop and wait for no one. I wish there were a button to cancel my request when I manage to cross on my own, or like you say, a system that will detect bikes and change the light before they reach the intersection.