Even the transportation of waste in London is chaotic. Rubbish from Westminster, for example, is carted in vast lorries across central London to incinerators in Deptford, or to huge landfill sites in Essex. Meanwhile, waste from southLondon is often carted up to landfill sites in Buckinghamshire, because councils have contracts with waste disposal units nowhere near their borough. Experts estimate that up to one in eight of the vehicles on London's roads are involved in some aspect of the disposal of waste.