M25 motorway re-examined as a motorway route in Sir Charles Bressey's and Sir Edwin Lutyens' "The Highway Development Survey, 1937". Sir Patrick Abercrombie's "County of London Plan, 1943" and "Greater London Plan, 1944" proposed a series of five roads encircling the capital. The northern sections of the M25 follow a similar route to the World War II Outer London Defence Ring, a concentric series of tanks and pillboxes designed to slow down a potential German invasion of the capital. Little was done to progress these plans until the 1960s when the Greater London Council developed its London Ringways plan consisting of four
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