Driving along an open road that skirts the perimeter of a military airfield, you see a triangular sign with a red border showing the silhouette of an aircraft flying low and level. There is no runway crossing the road here. What is this sign warning you about?
- That the road ahead may be closed at short notice while aircraft physically cross the carriageway on their way to a runway
- That low-flying aircraft or sudden, intense aircraft noise may occur near this stretch of road, which could startle you or briefly distract your attention, so you should stay alert and keep control rather than react suddenly
- That the area is a known bird-strike zone and you should watch for large birds crossing low over the road
- That a reduced maximum speed limit specific to aircraft noise applies for the length of the airfield boundary
Why B? And why not the others?
Correct answer: B. That low-flying aircraft or sudden, intense aircraft noise may occur near this stretch of road, which could startle you or briefly distract your attention, so you should stay alert and keep control rather than react suddenly
The low-flying-aircraft symbol is a warning triangle whose purpose is to alert drivers that aircraft passing low overhead, or a sudden burst of engine noise, can occur without warning near airfields and training areas; the sensible response is to stay alert and keep firm control of the car rather than flinch, brake sharply, or swerve if startled. The option describing aircraft physically crossing the carriageway describes a genuinely different situation, an airfield runway crossing a public road, which is a distinct hazard with its own signs and lights and is not what a plain low-flying-aircraft warning triangle depicts when no crossing is present. The option about a bird-strike zone invents a wildlife hazard the sign does not represent; the pictogram is an aircraft, not a bird, and the two hazards are unrelated. The option asserting a specific reduced speed limit fabricates a numeric restriction: a warning triangle by itself imposes no mandatory speed, and any actual speed limit near an airfield would need its own separate regulatory sign to have legal force.
Source: GOV.UK, The Highway Code — Traffic signs (warning signs, low-flying aircraft or sudden aircraft noise); DfT Know Your Traffic Signs