I guess I don't really mind paying something extra. But when you think about it a bit, I do own a vehicle and pay tax when I buy it, and I pay tab costs to keep it on the road, and fuel tax to operate it.
My using my bicycle as much as I do (20 miles round trip each day for commuting, plus trips to stores for groceries and whatnot and visiting friends and so on) the state has the benefit of my tab fees and sales taxes without the wear and tear on the roads that actually using my vehicle would cause. The bicycle is far less impact in terms of wear and tear and congestion than my vehicle would be. Seems like this might balance it all out somehow?
Having said that, I actually wouldn't mind paying something extra to help keep some sensible improvements coming in the way of bike safety on the roads. I wonder what the cost of administering and enforcing this would be versus the revenue gained? Consider that as things stand, I have never seen a policeman stop a bicyclist to enforce any traffic laws. Hard to imagine they would enforce a tab law of some sort.
I have to admit, in many cases I think one of the biggest safety improvements Seattle could make would be simply repairing the roads themselves instead of letting the roads break apart the way we do. Perhaps I am more sensitive to it since I ride a bike so much, but yoweee. Seattle's roads are in pretty pathetic shape. I do notice it when I drive as well of course, but on a bike? Woohoooooo!