Originally Posted by
Stealthammer
I use to believe that a solid red taillight was the most visible and safest, and that blinking was just confusing to drivers, until I tried a blinking light about ten years ago and I realized that I too was afforded more room by most passing motorists, and it even seemed to extend to using the blinking taillight during daylight hours. When I asked several co-workers who pass me often on my rides to/from work, each told me that the blinking light caught and maintained their attention better that just a sustained red glow.
It appears that humans notice flashing lights better, especially from long distances, than they do steady lights. If that wasn't the case, it's not likely that flashing lights would be the norm on things like emergency vehicles, airplanes, navigational aids, and towers.
I dont think drivers are confused by flashing bicycle lights either (they learn pretty-quickly what they represent). Anyway, being confused isn't necessarily a bad thing since they are aware of a thing to be confused by it. I suspect that some collisions are due to drivers being aware of the cyclist too late (later than they need to be able to avoid the cyclist).
Originally Posted by
Stealthammer
I can offer no scientific analysis, but it does occur to me that more "non-natural" flashing warning lights flash for a reason, and since that has become customary in most traffic situation, people have been "programmed" to recognize the purpose of a flashing light. I have alway ridden since then with my taillght blinking and I am confident that it is a safer approach.
I tried looking for a reference. Still, there is a fair amount of flashing-light usage (emergency vehicles, airplanes, navigational aids, and towers) that indicates that they are useful for noticing things from long distances.
The longer the distance that something can be noticed increases the likelihood that it will, in fact, be noticed.
Originally Posted by
Stealthammer
As for the florescent green vs bright yellow debate, again I would suggest that the florescent green used is a "non-natural" occurring color and it will stand out more than any other color commonly seen. I believe that this, and the fact that it was found to be more visible when seen through a smokey environment, is why many if not most, rescue/firetrucks used on airfields are painted this color.
Part of it is because yellow-green is not a common background color (kind of obvious).
Another reason is that yellow-green appears brighter to the human eye.
A range of wavelengths of light stimulates each of these receptor types to varying degrees. Yellowish-green light, for example, stimulates both L and M cones equally strongly, but only stimulates S-cones weakly. Red light, on the other hand, stimulates L cones much more than M cones, and S cones hardly at all; blue-green light stimulates M cones more than L cones, and S cones a bit more strongly, and is also the peak stimulant for rod cells; and blue light stimulates S cones more strongly than red or green light, but L and M cones more weakly. The brain combines the information from each type of receptor to give rise to different perceptions of different wavelengths of light.
http://en.wikipedia.org/wiki/Color_vision
http://en.wikipedia.org/wiki/File:Eyesensitivity.png