與主要交通燈顯示相同燈號的交通燈，通常設於路口對面，主要交通燈失靈時必須遵守其指示。
A duplicate of the main traffic light, usually on the opposite side of the junction, which must be obeyed as if it were the main light if the main light fails.
與主要交通燈顯示相同燈號的交通燈，通常設於路口對面，主要交通燈失靈時必須遵守其指示。
A duplicate of the main traffic light, usually on the opposite side of the junction, which must be obeyed as if it were the main light if the main light fails.