If my motorcycle has to be licensed, insured, registered, taxed and inspected as a road using vehicle, so does your bicycle. The wear a motorcycle puts on the roads is indistinguishable from a bicycle.
Also, in my state, road taxes DO pay for roads.
Bicycles want dirt. Motorcycles and cars want asphalt.
Remove the asphalt and concrete first, like nature provides.
Like Obamacare, bicycles cannot pay taxes for something they do not need.