It is clear cut because when you obtained your driver's license, you have had already signed and agreed to reveal your name on a "traffic" stop because you are

It is clear cut because when you obtained your driver's license, you have had already signed and agreed to reveal your name on a "traffic" stop because you are on public road with intent for commerce (or not). Walking on the sidewalk, your D/L, not so much unless you were operating a vehicle, registered or not.