| − | The Circle line is a "virtual" line on the system that has no actual track. It's coloured yellow on the map and, contrary to its name, since 2010 actually forms a spiral shape. | + | The Circle line is a line on the system that mainly operates over the track of other lines(the Metropolitan, District and Hammersmith & City) although it has two small sections of track only served by the central. It's coloured yellow on the map and, contrary to its name, since 2010 actually forms a spiral shape. |