M25 motorway Europe's second longest orbital road after the Berliner Ring, which is . Originally built almost wholly as a dual three-lane motorway, much of the motorway has been widened: to dual four lanes for almost half, to a dual five-lanes section between junctions 12 and 14 and a dual six-lane section between junctions 14 and 15. Further widening is in progress of minor sections with plans for managed motorways in many others. To the east of London the two ends of the M25 are joined to complete a loop by the non-motorway A282 Dartford Crossing of the River Thames between Thurrock
West London Orbital the Mayor's Transport Strategy was published, which includes a proposal for this 'orbital' connection to Old Oak between Hounslow and Brent Cross. The London Mayor's Transport Strategy (MTS), published on 28 February 2018 and ratified by the London Assembly on 8 March 2018, includes plans for a West London Orbital railway line under Proposal 88. The mayor’s proposal for the service highlights that utilising new and existing orbital connections in west London could also improve public transport connections in the city centre. It reads: “Most Londoners want to move around London – rather than in and out of the centre