As a city combining both modern and traditional architecture, Beijing is an ever-changing megacity rich in history but also truly modern, exemplified in its global influence in politics, business & economy, education, history, culture, language, music, sporting, architecture, civilization, fashion, art, entertainment, innovation, and technology. Beijing is the second largest Chinese city by urban population after Shanghai and is the nation's political, cultural, and educational center.[11] It is home to the headquarters of most of China's largest state-owned companies and is a major hub for the national highway, expressway, railway, and high-speed rail networks. The Beijing Capital International Airport has been the second busiest in the world by passenger traffic since 2010,[12] and, as of 2016[update], the city's subway network is the busiest and second longest in the world, after Shanghai's subway system.