What do two side-by-side alternating dashed white lines define?

Two side-by-side alternating dashed white lines define the edge of a vehicle roadway. In aviation environments, these markings are essential for guiding both ground vehicles and aircraft to ensure safe movement on the airfield. The use of alternating dashed lines helps to clearly differentiate areas where vehicles are authorized to travel from those that are not, thereby enhancing safety.

In contrast, other markings such as solid lines typically denote areas that should not be crossed, like the edge of a taxiway or runway. Understanding these distinctions is crucial for maintaining operational safety on the airfield, as it helps prevent accidental encroachment on restricted areas. Hence, recognizing the function of these dashed white lines is vital for any personnel involved in airport operations.