The OP, vja4Him, also posted his question 'Should bicyclists have to pay for registration, insurance and road tax for their bicycles?', over at Portland's bikeportland.org's forums.

I answered there:

"...
1) What, that's road related, should cyclists possibly pay for?

2) Considering certain uses of the road according to specific types of vehicle, why should cyclists pay for "... registration, insurance and road tax for their bicycles?" . "

At least at this point in how roads are being used by people that ride bikes, I don't see the reason they should pay the kind of things the OP, mentions, which I presume would be implemented primarily for the purpose of compelling a bike specific contribution to road construction and maintenance, as is the gas tax for motor vehicles.

It's wise to avoid placing any unnecessary burden on road users that are willing to ride a bike rather than drive a car, especially if they would be the only occupant of the car. At least five days a week, roads within the city and between suburb and central cities are clogged to capacity daily am and pm, with cars and more cars.

For the people that are fit, able, and hardy enough to ride them in extremes of weather, use of bikes for their transportation help reduce car produced road congestion. Not overlooking this contribution cyclists represent towards using road space more efficiently, if asked for additional contributions to fund improvements leading to safer pedestrian and bike infrastructure, I believe lots of cyclists would willingly offer it up.

Indirectly compelling cyclists to contribute bike related fees out of some sense that cyclists 'owe' the public for cyclists use of the road and for all the bike specific infrastructure being created to enable cycling to be an alternative to driving motor vehicles, seems to be a very unwise route to go.