Is public transit bottom up? I'd say just the opposite.

Id say it is. It's the local government chosen by the people deciding the infrastructure, rather than big car and oil companies controlled by a small group of oligarchs

Maybe it's a more complex matter? How about if people at the bottom were not continuously smacked by rich libertarian assholes and had a chance of having freedom of leisure, education, movement & all that good stuff that can make a citizen, who then is able to participate in decision making progress instead of being treated as animals for being poor? Feels bottom-up to me.