Doug and I had a relatively extensive discussion about this in the comments on my blog, though mostly just about the wisdom of an amendment. Granted, more people riding transit -> fewer cars purchased -> less funding for transit seems counterintuitive. But aside from that odd dynamic, using car-related tax revenues to fund transit makes sense in terms of taxing the more costly-to-society mode of transport and transferring the funds to the one with fewer negative effects. I believe this is pretty much the approach in a number of European countries, but they ratcheted up car-related taxes over decades and kept dependency from ever reaching American levels, so this feedback never happened. (That last sentence is pretty speculative.)

I guess it’s pretty much impossible that any political leaders will consider raising the level of tax in response to the declining revenue. If they wanted to be really snazzy and avoid some of the political heat, they could set the level of funding, instead of the level of tax, and have the tax automatically readjusted every 6 months or something by a formula to yield the desired level of funding. But that’s not happening, either…

That’s an awful lot to ask, dude.