How do runway approach boundary signs convey their message?

Runway approach boundary signs convey their message by depicting the pavement holding position marking. These signs are essential for providing visual cues to pilots and ground personnel about where they can safely hold or stop their aircraft in relation to active runways. The markings are designed to ensure that there is no confusion regarding the boundaries that must be respected, especially when an aircraft is near an active runway, thereby enhancing safety and operational efficiency at the airport.

The use of visual indicators, such as these markings, is critical in aviation, as pilots rely on clear, standard visual cues to navigate the airport environment. Flashing lights and sirens, while important in some contexts, are not a feature of runway approach boundary signs. Similarly, colored arrows showing runway direction or voice commands would not serve the specific purpose of defining holding positions. The focus here is on the visual aspect, which is why depiction of pavement markings is the correct choice.