in case one foot is damaged, the delineator can still be used with the second foot and does not necessarily have to be replaced
delineators with sloped reflective sheeting keep their guidance direction after reversal
one-sided delineators with reflective chevron sheeting change their guidance direction from "keep left" to "keep right" which means reduced costs for maintenance and replacement as well as for storage place as you only need to stock one type of delineator