What must be obeyed by vehicles on an airfield?

Vehicles operating on an airfield must obey stop signs as a fundamental safety requirement. Stop signs are critical controls that alert drivers to come to a complete stop at specific locations, which may be at runway crossings, taxiway intersections, or near sensitive areas where aircraft are in motion. Adhering to stop signs is crucial for preventing accidents and ensuring the safety of both ground vehicles and aircraft on the airfield.

While yield signs, warning signs, and directional signs also play essential roles in guiding vehicle operations on an airfield, stop signs specifically require drivers to halt and assess the situation before proceeding, thereby adding an extra layer of safety in potentially hazardous conditions.