I recently saw an argument that went recycling/trash trucks use too much fuel to really be a "green" technology. So, why not create a trash/recycling truck that runs on trash/recyclable materials? This eliminates the need to for people to worry about land fills while reducing the costs of the city to run trash vehicles. However, I do realize that burning the trash would require very thorough filtering, as who knows what people throw out. Perhaps adding a pseudo filtering to the trash system would help. Have the citizens separate out things that are combustible, like cardboard and food waste, versus thing that are not so combustible or too toxic, like aluminum cans and old clean containers. Perhaps, I am not the first to think of this, but it makes me wonder what technological or financial barrier exists to prevent garbage powered garbage trucks from existing.