China’s highway network is a complicated system that includes national highways, provincial highways, prefectural highways, and others, totaling 4.24 million kilometers in length. China’s expressway system consists of national and provincial expressways with design speeds of 80–120 kilometers per hour. The backbone of this expressway network is the national-level expressway system called the National Trunk Highway System (NTHS). The NTHS has radial expressways (from the capital Beijing), north-south expressways, and east-west expressways. Each provincial-level division of China has its own expressway system as well. Some cities also build their own urban expressways to supplement the NTHS and provincial systems. The road system, with a total length of 111,950 kilometers by the end of 2014, is the world’s largest expressway network. It connects all provinces and ...