Import and export statistics, that is, the number of vehicles entering and leaving all toll stations in the whole road network within a specific period of time.
Cross-section statistics, that is, looking for one or several sections with relatively average traffic flow, and calculating the number of passing vehicles in a specific time period, which is divided into ascending and descending.
At present, there are electronic statistics abroad, with an average of 1-3km. There is an electronic sensor with a cross section, which is used to count the traffic volume of the road network and monitor the traffic jam. If the number between the two sensors becomes very unbalanced within a few minutes (that is, traffic jam or accident), an alarm will be issued.
China has not progressed to this level.