Being aware is everything, if you need to jump lanes in a split second for a dog/person or something you need to know who's where, what speed they're doing, and whether it's better to slam the anchors and pray for the best or swerve. Swerving is not the best decision most of the time and yet everyone does it.
If you're country driving and a kangaroo jumps out, never swerve, ever, slam on the breaks and brace. A lot of accidents are caused by people swerving at 110km/h.
The other thing to note is anyone tailgaiting somebody else, they are more often than not shit drivers, if not they will be aggressive at the least and they will be more likely to make poor decisions.