Stephan Wilkinson at The Truth About Cars has noticed that school buses in his neighborhood seem to all leave at the same time, carrying only a few kids each. Additionally, they idle for long periods of time before and after they leave, at which time they belch out harmful toxins. He seems to think that the school system could make much better use of the equipment that they have and that they could probably get by with much less. This is likely a problem in wealthy communities the country over. A potential solution exists in biodiesel buses and hybrid buses, which are likely to hit the market soon enough, but in the meantime, if this is a problem in your own school district, you can do what Wilkinson plans to do and speak with the school board.
[Source: The Truth About Cars]