The Impact of Environmentalism: Transport

Are we doing enough to make our transport sustainable? Is green thinking making a difference?
We are all aware of the importance of the environment - it's always in the news and it affects our behaviour and the decisions we make every day. But what actual impact has environmental thinking had on the transport we take for granted?
This thought-provoking series looks at the way changing ideas about the environment and sustainability have affected our landscape, conservation efforts, transportation, food and farming, and our towns and cities.