Nice article on the BBC website: http://www.bbc.co.uk/blogs/ethicalman/2009/11/why_cars_are_greener_than_buses.html
All metric. Even the readers' posts are substantially (if not totally) metric, which is very encouraging especially when it is considered that this is a transportation article and the UK's transportation (road and rail signage) system is primarily imperial. As for whether you agree with the article or not, it can be seen that the subject is highly complex with ne easy solutions.
