Like he said, its worthless.
If a car is coming up on your retro-reflective tape is going to be much more valuable. Reflected headlights are going to be much much brighter than any glow.
If there are no cars around and all you want to do is alert pedestrians, then a headlight and taillight are going to work better, I doubt any glow is going to be visible till you're within a few feet; by then you've already hit the guy.