Not always. I some places, bikes and motorcycles are free to proceed after waiting a reasonable amount of time and ensuring no incoming traffic, since many sensors that flip signals can't detect either one.
Understand about the sensors but if a driver did that he’d get a ticket. Or can we do that too “if there’s nothing coming”? And I don’t mean in the middle of the night I’m talking like 2 in the afternoon when I see bike riders cruise right through.
Traffic signals use a design called a Colpitts Oscillator. Essentially, when a chunk of iron sits near a coil of wire buried underground, the frequency of the oscillator changes, which tells the sensor that there is a car, truck or big chunk of metal nearby.
Most bikes made from the mid-70's have moved away from iron; as iron is really heavy. Most bikes use either Aluminum or some alloy of non-ferric metals - so they do not trigger the oscillator like the old, heavy bikes did.
So, when you ride a bicycle - you could sit on that sensor all day long. So, allowing the bike to proceed after coming to a complete stop makes sense. Whereas motorcycles, cars and trucks have enough iron in them to trip the sensor. Just a FYI.