When should alternating flashing amber warning lights be activated? Do you currently have commercial insurance? Commercial Insurance is mandatory for CDL drivers in Ohio Yes I have insurance. But please show me your best quotes. No, please help me find the best insurance. Question When should alternating flashing amber warning lights be activated? Answers When a bus is within 10 feet of a bus stop When a bus is about 50 feet from a bus stop When a bus is at least 300 feet from a bus stop When a bus is 1,000 feet from a bus stop Explanation The driver of a school bus must activate their amber warning lights at least 300 feet before reaching a bus stop to warn surrounding drivers about the upcoming stop.