Personally I suspect it's because a lot of people in these parts do not learn to drive under pressure. They live out in the boonies and learned to drive on uncrowded roads where you don't have to follow the rules. Then they get here, to the Big City, and are not prepared. Go down to So Cal, pull the crap people do around here, and you wouldn't live long enough to worry learning to drive better. Look at all the folks that drive down here from Marysville or North Bend, they can just toodle around their roads without thinking about anyone. Think of all those horrible Snohomish County crashes.
Not to be racist, but...
I have heard from reliable sources (while I can't remember the particular citation I think I was listening to KUOW) and they were discussing the bad driving in China -- they were prepping for the Olympics as I recall; all of a sudden pathes were replaced with roads & bikes with cars. Without the history & experience of driving there were a lot of bad drivers making their own rules. If that's accurate, I'm sure we see some of these folks vacationing or moving here.
My buddy is married to a Japanese lady (like, really from Japan). He says she & her friends are terrible drivers. But, I'm not educated enough to make a guess as to why that would be, if true at all.
I have an attorney friend that was telling me about his exprience driving in India. Crazy--completely different from our rules, well no rules at all accornding to him. I suspect if someone that learned to drive in India, came here and got behind the wheel day on day one, they or someone else would have their car in the body shop momentarily.
Just recently I've noticed that Latin/Mexican guys seem to drive slowly, but obey the rules. I wonder if that's just a coincidence since I've never heard any stereotyping jokes about it. But, it got me wondering if the experience of driving south of the border, needing to be extra careful the coppers don't have any reason to pull you over and shove you in one of their legendary jails, encourages this caution.
Again, I don't mean to come off racist, but more so would suggest that the culture you come from, be it some bohunk from the hicks who thinks the sun rises and sets on his butt & the rules apply to everyone else, or some little old lady that just arrived here from somewhere that your feet provide mobility not petrol, determines how well you operate in the more densly populated nation of Ballard. I kinda bet that would apply to more than just driving. And of course, here we are the melting pot of melting pots. Just my two-cents.