At least where I live, Bikes are legally considered Cars in most cases.

Under Ontario’s Highway Traffic Act (HTA), a bicycle is considered a vehicle, just like a car or truck.

As a cyclist, you:

• must obey all traffic laws
• have the same rights and responsibilities as drivers
• cannot carry passengers if your bicycle is only meant for one person

Also, this is the official documentation in Ontario for bike signals, not sure how it compares to other parts of the world.