Expressway is a high-grade highway. According to the Technical Standard for Highway Engineering of the Ministry of Communications of China, expressway refers to a highway that can adapt to the annual average day and night passenger car traffic of more than 25,000 vehicles and is designed for cars to drive at high speed in a single lane, and all access is controlled.
Although different countries have different names for expressway, they all refer to expressway with four lanes or more, two-way separation, complete control of entrances and exits, and all interchanges. In addition, many countries also refer to direct trunk lines as partially controlled entrances and exits, but not all countries regard interchanges as expressway.
Generally speaking, expressway can adapt to the speed above 120km/h (generally 120km/h), and the road width is above 4 lanes (inclusive). There is an isolation belt in the middle, asphalt concrete or cement concrete advanced pavement, and signs, markings, signals and lighting devices are complete. Pedestrians and non-motor vehicles are prohibited from walking on the road, and other lines are crossed by interchanges, footbridges or tunnels.