High speed refers to advanced speed, compared with medium speed and low speed. In the environment where low speed is dominant, low speed is normal speed or constant speed, and in the environment where medium speed is dominant, medium speed is normal speed or constant speed.
The relationship between high speed and fast speed, the generalized fast (the comparison between speed and slow speed) in dichotomy includes high speed relative to slow speed, but the word fast does not mean high end, and in the comparison of many things, fast is higher than low speed, lower than high speed and quasi-high speed. In dichotomy, fast is called medium speed, which is higher than normal speed and lower than high speed. In dichotomy, expressway is lower than expressway, express railway is lower than high-speed railway, and express train is lower than high-speed train. Expressway, referred to as expressway for short, refers to the expressway dedicated to high-speed driving of automobiles.
Expressway has different regulations in different countries and regions, different times and different scientific research and academic fields. According to relevant regulations, expressway is a multi-lane expressway for cars to drive in different directions and lanes, and all access is controlled.
Although the renaming of expressway will cost a lot of society, and the transition period of renaming will bring inconvenience to many travelers, it is extremely necessary for the traffic management department to implement the digital naming of expressway as soon as possible, because it fundamentally involves the "path dependence" of the system development, and the later changes will make the whole society pay a greater price.