I night-ride in suburban/rural conditions. In town, traffic is held to 30mph in places, 45mph in others, in the unincorporated area between the three towns in my commute, traffic can hit 55 mph (and more). At any speed I might manage... even on my downhill runs, I am essentially stationary to an overtaking car. Any car that picks up my rear flasher will treat me exactly like he would treat a pedestrian walking in the shoulder. Pull over into the passing lane, or make no alteration to his path and blast by at speed if s/he is an *******. In any case s/he has seen me. That's what I wanted. Solid red vs flashing... give me flashing, thank you. Your batteries last much longer and the dazzle cannot be ignored by a driver the way a solid red can. Cars and even motorcycles can get away with solid red rear lights because there is so much more lit surface sending photons out than one tiny flasher can manage. Some motorcycle tailights go into a momentary flash mode when the rider applies the brakes. This acknowledges that the people who design and manufacture tail-lights know that flashing lights get attention. I was riding behind a cyclist whose flasher had such a slow period that he was invisible for whole seconds between light pulses. My PlanetBike strobes so quickly its never completely dark. IMO it has the best of both worlds. Steady and flashing at the same time if you can picture that. Still, I think the steady thing is over-rated, a driver doesn't need to know or care how fast you are travelling as a cyclist. You are essentially stationary as far as s/he is concerned. Works for me.

H