Are integrated helmet lights bright enough to replace a separate rear light?

Integrated helmet lights are convenient and ensure you always have a rear light, but they typically produce 20-50 lumens compared to 50-200+ lumens from dedicated rear lights. For well-lit urban streets, integrated lights are adequate. For darker roads or higher-speed traffic, supplement the integrated light with a dedicated rear light mounted on your bike or bag. Think of the integrated light as your always-there baseline, not your only visibility tool.