I have used flash mode during the day on my headlight, but after having an oncoming cyclist angrily tell me to turn it off I've reconsidered it. I spent some time looking at my bike's headlight from the perspective of others and I think even tilted down a little and during daylight hours, my headlight is still way too obnoxious in flash mode. It's too bright for its own good. I think a low power, dedicated visibility light might make more sense if that's something you want. I'll just run my light in a solid low power mode if I feel I need to be a little more visible.