Yes, but in the real world where we don't live in a tyrannical CCTV surveillance state, or one with unlimited resources for road policing a great many are getting away with murder. We don't live in a small scale community where everyone knows everyone, I guess I don't need to remind you some don't care much for fellow countrymen. We might rely on self control in a small community where there would be real repercussions within the community for mistreating your kin on our roads. (Ideally with hangings and quarterings, or if we are feeling more civilised, exiled from the tribe with the likely consequence of starvation or being preyed upon by larger mammals). In our larger more anonymous society, even with number plates, we can't realistically expect everyone to follow all the rules all the time, so we need to improve on elemetns of all of the above, and a sensible approach to infrastructure can be part of that tool kit to keep us safe and encourage more people out onto bikes. If we expect people to mix with motors driven by idiots, then we can realistically expect an intolerable number of deaths and injury and very low modal shares, as we see today. I don't doubt the numbers would be far worse if 98% of us hadn't been frightened off our bikes on our roads and into cars, buses or trains. The idiots won't disappear no matter how hard we wish them to, invariably many will still get behind the wheel even with revoked licenses (I would personally reserve the ritual hangings for them folk.)