If you only pass through the middle and high risk area, the health code will not change color. Health codes do not collect personal location information, but identify health status according to the data of authoritative departments. The online saying that "it will change color when passing through the middle and high risk area" is inaccurate. If you only pass through the middle and high risk area, the health code will not change color. The route refers to people who have stayed in the relevant areas, including cars or trains passing through relevant stations in high-risk areas. Only when passengers get on and off will they change color.
High-speed railway:
High-speed railway, referred to as high-speed railway for short, refers to a railway system with high design standards and high speed for the safe running of trains. Its concept is not limited to tracks, let alone trains. High-speed rail has different regulations in different countries, different times and different scientific research and academic fields. The Code for Design of High-speed Railway issued by China National Railway Administration defines high-speed railway as a newly-built passenger dedicated railway with a design speed of 250 km/h to 350 km/h and running the standard gauge of EMU trains.