www.monash.edu.au/muarch/reports/atsb174.html
I think that's the link above. I emailed it to my wife, since she's threatened to find-and-destroy my DOT approved half-shell. I'm sorry, but it's just very pleasant to actually feel the wind on your face when you're riding (as opposed to riding at dusk, when you feel the mosquitos on your face, and it's quite nice to have a visor).
