What does subject 1 26 1 145 520 mean?

What does subject 1 26 1 145 520 mean? In Subject 1, 26 1, 145 and 520 refer to the visibility, maximum speed and minimum distance of vehicles in expressway in rainy and foggy weather. The details are as follows: 1 and 26 1: 26 1 indicate that the visibility in expressway is below 200m, the top speed is 60km \u002F hours, and the minimum distance between cars is 100m. 2. 145: 145 means that the visibility of expressway is below 100m, the maximum speed is 40km \u002F hours, and the minimum distance between vehicles is 50m. 3.520: 520 means that the visibility of expressway is below 50m, and the top speed is 20km \u002F hours, leaving expressway from the nearest exit. @20 19