Lights

No fucking way. A light that bright will dazzle drivers. And don't even get me started on how fucked up it would be with one of those things shining directly in your face as a cyclist.

if you set it constant, it won't dazzle others, but on flashing mode, it will.

I leave mine on constant, much more predictable and because of the way the flare.. well, 'flare', no one can says they can't see me.