Airport, bus, subway, big trucks, coach, expressway passage, railway. The information of key industries in Tianjin shows: employees in airports, buses, subways, large trucks, long-distance buses, highway passages, railways and other industries, and traffic infrastructure construction and maintenance personnel under centralized residential management. Tianjin, referred to as Jingu and Jinmen for short, is a provincial-level administrative region, municipality directly under the Central Government, national central city and megacity in People's Republic of China (PRC), a gateway to the opening up of northern China approved by the State Council, and a shipping center, logistics center and modern manufacturing base in northern China.