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 Underground infrastructure in 1999, and key interchange stations such as King's Cross St. Pancras, Victoria station and Green Park becoming step-free. Over 28 stations will become step-free over the next 10 years, taking the total step-free stations to over 100. In October 2015, TfL installed the first incline lift on the UK transport network, at Greenford station. The London Underground comprises eleven lines. London Underground trains come in two sizes, larger sub-surface trains and smaller deep-tube trains. Since the early 1960s, all passenger trains have been electric multiple units with sliding doors and a train last ran with a guard in 2000.