予よ告こく信しん号ごう

noun

advance warning signal; preliminary traffic signal

A traffic signal that gives advance warning of an upcoming signal, often used on high-speed roads or where visibility is limited.

• このカーブの先さきには予よ告こく信しん号ごうが設せっ置ちされている。

  An advance warning signal is installed ahead of this curve.

• 予よ告こく信しん号ごうが黄き色いろに変かわったら、減げん速そくして本ほん信しん号ごうに備そなえてください。

  When the advance warning signal turns yellow, slow down and prepare for the main signal.