It's easy to get frustrated in the car. We all do. Maybe a guy in front of you is continually tapping his brakes, worsening stop-and-go traffic. Or perhaps it's a lady yapping on her phone, not bothering to check the mirrors before she changes lanes. Under normal circumstances, if no harm comes of it, it's not terribly hard to let these things pass. But if you've got a million errands to run and a crying baby in the backseat, you can hit the boiling point pretty quickly -- and that can lead to serious consequences. If you've been acting more aggressively on the road lately, it might be a sign to cut back your to-do list.