What does the white semicircular marking mean?

[LaAmir]

White semicircular markings refer to distance confirmation lines, which typically appear on highways; the hemispherical radius of white semicircular distance confirmation lines is 30cm, spaced at 50m intervals, and are usually set consecutively over certain road sections. Additional information: Purpose of white semicircular markings: Distance confirmation lines primarily serve to remind drivers to maintain a safe following distance from the vehicle ahead to prevent traffic accidents. Distance confirmation lines generally come in three forms: white zigzag distance confirmation lines, white semicircular distance confirmation lines, and white rectangular distance confirmation lines.