It's aggravating enough at gas stations, malls, and the like, but the ones who drive me absolutely bonkers are the distracted fools on divided highways that won't stick to their lane.

It's always worst when snow obscures the markings, but even on clear days, you often see some yutz straddling a lane.  I am nervous about passing these yo-yos, since you never know if he will suddenly decide to commit to a lane (no shoulder check, natch) or obliviously drift to the left, sideswiping you.