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
London commuter belt East and South East regions. Most districts are entirely, or have sections, within the M25 motorway or are within of Charing Cross. Adjacent districts often share characteristics of Outer London, such as forming part of the continuous urban sprawl, being served by the London Underground, being covered by the London telephone area code, (until 2000) forming part of the Metropolitan Police District and having a relatively high employed population working in London. Larger Urban Zone is a definition created by Eurostat that measures the population and expanse of metropolitan areas across European countries. The population of London's Larger Urban Zone