Cars and lorries cause congestion, noise, local pollution, harm to health, destruction of habitats and biodiversity, and global warming. Transport accounts for around 30% of UK CO2 emissions with the overwhelming majority via personal vehicles. These problems can really only be tackled by using cars and lorries less - and instead looking at alternatives such as trains, buses, trams, bicycles and our feet.

At present about 80% of the world's demand for transportation fuels is met by derivatives from the fossil fuel, petroleum. Petrol, one of the major derivatives of petroleum, is used throughout the world as a motor vehicle fuel.

Public transport can emit less pollution than private vehicles, per person transported, and can be the most sustainable form of motorised travel. However sometimes car use is essential and in some cases environmentally preferable, so when using a private vehicle for a given journey it is important to reduce its environmental impact to the minimum.