T. Cox,

According to the following article only 40% of the road budget comes from gas taxes: http://www.stateline.org/live/ViewPage.action?siteNodeId=136&languageId=1&contentId=32957

This means that 60% of the budget comes from elsewhere - places where cyclists DO pay taxes.

It is estimated that 5% of trips in Portland are by bike. 5% of that 60% is 3% of the total budget.

Other numbers say that 2% of the road budget goes to cycling specific projects. 2% is less than the 3%.

Bicyclists pay more than their share of the road.