COMMENT WITH ALAN MILLAR
As a bus passenger, what do you value more highly? A zero- or ultra low-emission vehicle that delivers better air quality or the assurance that you are unlikely to be harassed by antisocial individuals misbehaving on the bus or while you wait at the stop?
In an ideal world, there should be no need for a choice. You should expect both. The bus will be kind to the environment and the fellow humans you encounter on your journey will be the very models of acceptable behaviour. But life is not ideal and the lack of one of these ideals is more likely to influence your decision about whether or not you make a particular journey by public transport.