My kid was in the hospital in Chicago and there were a ton of shuttles that run routes between the various hotels and the hospital. In a big city, shuttles have a lot more flexibility than buses. While I don't know if Chicago has something akin to dollar vans, I could see it really working if those shuttles all just added a few extra stops. A lot of cities have shuttles organized to do the routes between colleges and bars, usually owned and managed by the bars themselves.