Why does the low air pressure warning need to include both a visual and an audible signal rather than just one?

Pick an answer

1. It is a stylistic choice with no safety justification
2. Only an audible warning has ever been required, since a light alone is considered optional equipment
3. Visual and audible signals serve entirely unrelated purposes
4. A driver might not notice one signal alone, especially if attention is elsewhere at that moment

Correct!

Not quite. The correct answer is highlighted.