The Central line is long and serves 49 stations. The line is predominantly double track, widened to three tracks for short sections south of Leytonstone and west of White City; no track is shared with any other line though some sections do parallel other routes. Total track length is , of which is in tunnel; this track is electrified with a four-rail DC system: a central conductor rail is energised at −210 V and a rail outside the running rail at +420 V, giving a potential difference of 630 V.