Hongkaiqiao Village Subway in Chating Town, Wangcheng District, Changsha City, Hunan Province is Metro Line 6, which was opened on June 27th, 2022.
In addition to the subway, it also includes elevated railways or railways laid on roads. Therefore, the subway is the exclusive right of way, and there is no grade crossing, which is also the fundamental sign that the subway is different from the light rail transit system. The earliest (and first) subway in the world is the Metropolitan Subway in London, England, which was built at 1863.