¿Qué comportamiento exige un semáforo con una o dos luces amarillas alternativamente intermitentes?

Under the General Traffic Regulations (RGC), one flashing amber light or two alternately flashing amber lights have the same meaning: they require you to take extreme care. This means that the driver must slow down and be ready to stop if necessary, giving way to other vehicles or pedestrians who have right of way. Do not confuse it with two flashing red lights, which indicate a temporary ban on passing (common at level crossings or fire station exits). So it does not require an immediate stop like a red or steady amber light, but alert, defensive driving.