Easy to use. According to the inquiry of Zhuanghe expressway Administration Bureau, the speed limit equipment between Zhuanghe and Qingdui strictly enforces traffic regulations to ensure road traffic safety, so the speed limit between Zhuanghe and Qingdui is easy to use. The so-called interval speed measurement refers to the method of detecting the average speed of motor vehicles passing through the road section (speed measurement interval) between two adjacent speed monitoring points.