Remember kids... always wear a helmet. (The almighty bikeradar helmet thread)

To all females:

It is very naive and dangerous to assume that drivers will give you more space, just because you are female.

No it's not, it's something I notice actually, vehicles somehow pass you a little closer than they should if you're wearing a helmet, the whole notion of "oh they're wearing a helmets, they'll be fine" and overtake them leaving less space to spare, not on purpose of course as drivers tend not to know how scary it is when a motorised vehicle pass you very closely even at 20mph.

Now I seen this pattern, people who's full on noddering it, somehow drivers didn't really take much caution around them, whether those who didn't wear a helmet, they do take a little caution around them, and women who let their hair down, they take even more caution overtaking them (probably because of the silly notion that female can't ride a bike as well as men or simply because they're female)

I also notice the worse cyclists, weaving left and right with phone on their hand, it force drivers to the point of having to go on the other lane just to overtake the bad cyclist.

however having said that, it doesn't mean they'll always give you a bit more space, but they appear to be more frequents in doing that if you're not wearing a helmet/are a women.

tricity's right, there is a study related to this matter, I've just found it;

http://www.drianwalker.com/overtaking/