Like virtually all major cities throughout the world, London has a major traffic, congestion and air pollution problem. But London is way better than most, primarily because its public transport is so all-pervasive, ubiquitous and efficient. Its iconic big red busses go just about everywhere, together with the Tube (underground railway) and surface rail systems; you can usually use these to get where you want to, way before most conceivable alternatives. Except, perhaps, the device chained to railings in the foreground...