I think in regards to the lights flashing vs steady vs having one steady and other flashing (which is the way I do as I posted earlier) is correct. The question does become though in relation to brightness is how much is too much. I've found that my Mars 4 is plenty bright enough and can be seen in daylight, I've had drivers tell me they could see it daylight and from a distance. I don't think you want to be brighter then a standard automotive tail light though, this may piss off some drivers and could cause more problems then it solves...but having never tested something brighter then a car tail light I could be wrong. But you do want to be seen, thus is why I use the Mars 4 on steady at night and the barend lights and rear helmet light on flashing.