M26 motorway the M26 at that time formed part of Ringway 4 and would have been designated as part of the M25. Construction of the first part of the M25 began in 1972 but before it opened, plans for the "London Orbital" motorway were modified to combine the southern and western part of Ringway 4 with the northern and eastern part of Ringway 3. To connect the two separate routes, which together were numbered as the M25, an additional section of road needed to be planned and the M25 route was diverted northwards from junction 5 to meet Ringway 3 at Swanley
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