The costs of elevated facilities would draw such outrage at the 'misspending" of taxpayer dollars, there would likely be riots in the streets.

Well, probably not riots, but seeing as many people don't feel that bicyclists foot enough of the bill to justify painted lines on the side of the roadway, getting something actually worth money built to benefit a small segment of the population would be next to impossible.

Give it a few years and when most people are priced out of being able to drive cars, the streets will become defacto bike only facilities.