The thread from a few days back on bright blinking lights was very interesting. I'm not arguing against shaped beams at all. They really seem pretty effective. Neither am I saying that some lights are too bright. I'm only going to relay the experience of the very informal, very unscientific experiment with my light.

I'm running a Cygolite Metro 500 mounted on the handlebars. The daytime flash mode produces a claimed 600 lumens. I have never had anyone complain about my light. I have had several compliments on it and the distance that it is visible. I don't use flashing at night. I don't use it on the MUP. I have always kept it pointed down so that the splash on the road is approx 10'-12' ahead of the front wheel.

The comment that got my attention in the thread I mentioned was regarding judging speed and distance of a very bright flashing light. Now I am firmly on the side of wanting to be seen above all else and I think my light accomplishes that, at least on my commute. The problem that I have complained about in the past, and had others agree, is that drivers want to wait too long at a stop sign while I'm approaching on the through street. I mean a half block, really? Do they think UFO is coming down the street? A real pain, I think. Makes me wonder if they can judge speed/distance at all and may pull out just as I get there. I began to consider if the light could be causing at least part of their inability to judge.

I started my "test" 2 weeks ago. Pointed the light farther down so that the splash is about 4'-5' ahead of the front wheel. With my "alert" set on high I rolled out. I could tell the light still flashed on traffic signs 3/4 of a block away in the lower light of morning. That made me feel like I would still be seen by drivers. The difference was immediate. The traffic began to "flow" better. Drivers began to pull out ahead of me, as they should, without issue. Others, in line behind them, would pull up to the crosswalk and stay stopped until I cleared the intersection. They were seeing me. The question of being seen was actually answered on the 3rd day of the experiment. I met 2 other bikes on the way in to work. They flagged me down to ask what kind of light I had as they could see me from a very long way off. At least a half mile, probably more, by our reckoning. I saw their shape from several blocks away but, did not see their rinky dink light until we were in the same block! Convinced me that anything that blinks does not necessarily mean you can be seen.

This is just my experience of pointing my light [I]way[I] down. If anyone has the issue of drivers "freezing" at the stops for too long a period of time, you may want to try this on a segment of your commute that you would feel you could do so safely. YMMV. Be safe all.