You can get a MUCH BRIGHTER FLASHING RECHARGEABLE REAR LIGHT literally that will you REAL SAFETY even during full summer daylight - my current fav is the Cygolite Hypershot 350 rear fender mounted - I have friends that use the Cyglolite HotRod which mounts on seat tube. My Hypershot is 350 Lumens at Full Setting - the Hotrod at 120 Lumens is bright but not the huge safety factor of my Hypershot.
