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
West London Orbital to reach Brentford and Hounslow. Taken together, this set of routes would be known as the “West London Orbital” railway. In March 2017 the West London Alliance group of local authorities commissioned a study to assess the feasibility of the line so that a decision could be taken as to whether it merited pursuing further. This study found that: In June 2017 Transport for London published the draft Mayor’s Transport Strategy, which stated that London government would work with the relevant boroughs to explore the feasibility of the proposed service, that would become the West London Orbital. In March 2018