The best thing you can do is drive in a way that even bad drivers expect. Be a speed-limited, blinker-indicating, cautious log in the river. They will parkour around you and you will be fine. Greatly limit your reactions to things. If you freak out, others around you will freak out. Bad drivers cause okay drivers to perform worse. Herd mentality.
(Obvious disclaimer: The best defensive driving in the world won't prevent all accidents)