Bad drivers are a fact of life. It really drives DH nuts!! He will curse, honk, 'gesture', lecture, etc. to bad drivers. He will wave someone into traffic, and if they don't immediately respond-he cusses and cuts them off! It's a joy to be in the passenger seat!
I make excuses for people. 'Oh, he must be driving like a maniac because he has low blood sugar, She must have gotten a call that one of her kids is sick. etc.'
My kids say I drive like, 'Miss Daisy'. I stay in the right lane, with a nice following distance. If the light is yellow/red, I drift to the light. Try to keep the RPMs low. I always say, 'I pity the fool behind me, that's in a hurry!'