As the pace of modern life leaves no time to stand and stare -or indeed perform many essential activities as well the advent of the \"poo-powered\" bus certainly offers commuters chances of purposeful repose as well as gainful movement. Keeping in mind what these buses are obviously meant to run on, the feasibility of every vehicle being self sustaining becomes a distinct possibility. With the right technological input to maximise mutual benefits, the need for passengers to finance their ride with money could easily become quite unnecessary. A barter system with an option to store credits for excess contributions would be the obvious solution. Not only would it make those long trips to (or from) work a welcome relief instead of an unproductive bum ride, it would shave precious minutes off morning ablutions.
The implementation of this self-generating propulsion system would obviate the need for ordinary seats but the alternative arrangements for posterior positioners-cum-fuel collectors would also need a degree of privacy. That would mean accommodeating less passengers but that would definitely be offset by the money saved and pollution prevented, presumably. If this renewable energy source can be tapped efficiently for multiple requirements, practically every human habitation could potentially become self-sufficient.