It may seem like a cliche, but when you're driving in a crowded city you need to keep your eyes on the road and be ready for anything, from drunk drivers to unexpected car troubles to flat out operator error.
California is chock full of cars, and with so many drivers on the road you're bound to encounter a few with minds that aren't firing on all cylinders.
The woman in this video was taken to a hospital for a "non injury-related reason" then later charged with driving under the influence of drugs, which she was able to avoid due to "insufficient evidence to support a criminal complaint". Seems like this video should have been evidence enough!
-Via Boing Boing
It's a British thing.