I think there is definitely some very revealing information coming out of this study. For motorists to pass so much closer or farther based on a few variables like helmet/no-helmet, or gasp, guy or girl is a big deal.

I have short hair, wear graphic/team bike clothes, and have, as C-Mac confirmed, a racer girl body - so does that mean if I put on a waist length curly blonde wig and went for a spin that I'd suddenly get buzzed by cars less often? And if so why?

It seems to me that it indicates drivers think of women riders as less competent, more unpredictable, or simply dangerous to paint jobs on their shiny new BMW's. Which goes with what was said earlier about motorists probably thinking women riders are poor cyclists (or at least worse than men).

The other twist is the helmet vs. no-helmet thing. Essentially this study is suggesting you are going to get less room with a helmet. If you are getting less room then you are closer to being hit. Not at all encouraging and somewhat defeats the purpose of wearig a helmet to begin with. Granted, I always ride with one.

Attitudes defintely need to change among motorists. When gas hits $5+/gallon, it might just start happening.