I have one. Yes, legal in all 50 states and Canada. It gets the attention of other drivers and occasionally they will flash their lights. I just give them a polite wave knowing that they saw me. I do turn it off when sitting in traffic to not continually flash the driver in front of me.
Originally Posted by Vagabird
I also wear a high vis, Olympic AST jacket and have added flashing LED's to my brake circuit. When touring I use bright orange dry bags for my gear. I believe that visibility is the best defense. If a modulating headlight irritates a driver, at least he sees you.