Lane dividing lines are used to separate the traffic flowing in the same direction. Where there are two or more lanes in the same direction, lane boundaries should be drawn. There are two kinds of lane boundaries, lane boundary dotted line and guide lane boundary solid line. The dotted line of lane boundary allows vehicles to overtake or change lanes under the principle of ensuring safety; The boundary line of the guide lane is solid, and vehicles are not allowed to cross the line or change lanes. The function of road traffic marking is to separate motor vehicles, non-motor vehicles and pedestrians, improve road utilization rate, reduce or prevent traffic accidents, and increase its effectiveness with traffic signs and traffic signals.

There are more than 70 kinds of traffic markings, which can be divided into white dotted line, white solid line, yellow dotted line, yellow solid line, double white dotted line, double white solid line, double yellow dotted line and yellow virtual and real line according to marking methods. According to the function, it can be divided into roadway center line, lane dividing line, parking line, deceleration yield line, crosswalk line, guide line, guide arrow, left turn guide line and so on. According to the function, it can only be divided into three categories: one is indicative marking, the other is forbidden marking, and the third is warning marking.