The patrolman, also known as the security officer, is an auxiliary police officer in the establishment of a unit or public relations department, that is, a person who helps police officers maintain social order. Daily inspection is a general inspection of the appearance of roads, subgrade, bridges, tunnels and facilities along the line. The main body of daily inspection is the maintenance unit of each road section and the maintenance department of the management company. The inspection frequency of the daily maintenance unit is not less than once a day, and the inspection frequency of the maintenance department of the management company is not less than twice a week.