The Shanghai–Nanjing or Huning Railway is a 1,435 mm (4 ft 8+1⁄2 in) standard gauge railway in China running from Shanghai to Nanjing. The railway is about 307 kilometers (191 mi) long. The Huning line is one of the busiest in China. The Shanghai–Nanjing intercity railway runs along the same route, but on parallel tracks. Its Chinese name is derived from the character abbreviations Hù (s 沪, t 滬) for Shanghai and Níng (s 宁, t 寧) for Nanjing.