How often do you ride at night, and how much of that ride is on a street lined with businesses, streetlights, tail-lights, and other things? It sounds odd, but when I'm in a place that is pitch-dark I'm never scared of someone not seeing me, because I'm the only light on the road. However, when I'm riding on a high-traffic, fast paced road with lights everywhere you look, I want motorists to know I'm not just another light; I'm a living person.

I don't think a motorist would intentionally hit anything with a light. What I'm nervous about is people going around a turn, seeing a red light on the right side of the road that doesn't look to be moving, and thinking it's just another light on the sidewalk. Of course they'll probably notice I'm on the street sooner or later, but it could be too late.

If someone wants to add another light to their bike, it probably means that they're not comfortable at night with the amount of light they're putting out now. If you don't think his idea right now is beneficial, I'd suggest a way that he could be lit-up in a different way so he's more confident when riding. I've ridden with one blinking rear light and it was not enough light for me to feel confident on a bike. Now that I'm satisfied with my lights, I seldom get that temptation to hop in a car to get where I want to go if the sun is down.