London Underground with smaller trains that run in two circular tunnels ("tubes") with a diameter about . These lines have the exclusive use of a pair of tracks, except for the Piccadilly line, which shares track with the District line between Acton Town and Hanger Lane Junction and with the Metropolitan line between Rayners Lane and Uxbridge; and the Bakerloo line, which shares track with London Overground services north of Queen's Park. Fifty-five per cent of the system runs on the surface. There are of cut-and-cover tunnel and of tube tunnel. Many of the central London underground stations on deep-level tube routes
Transport in London implement the recommendations. In the 1960s the Greater London Council prepared a drastic plan for a network of London Ringways including the construction of the London Motorway Box which would have involved massive demolition and huge cost to bring motorways into the heart of the city. Resistance from Central Government over the costs and campaigns of objection from local residents caused the cancellation of most of the plans in 1973. By the end of the 20th century policy swung towards a preference for public transport improvements, although the 118-mile (190 km) M25 orbital motorway was constructed between 1973 and 1986