Some lights have push-buttons, but not all. Most lights these days have sensors, but not all of them are triggerable by bicycles. There is one light on one of my regular routes that would NEVER change if it was just me on the bike there.

That's the only one I'll run the red on, after I've sat for 5 minutes w/o the option of a green. I'll usually sit for a while first to see if a car will come up and trigger it. But in times of low traffic, that could take a long, long time.