The one thing I've noticed about people who drive is that no one has the patience for semi trucks. Yes, they are a little slower but have you thought of why? They are monster vehicles and have so much weight that they carry. It's not easy for truck drivers to slam on their brakes and stop instantly.
One car learned that the hard way. Once car merged in front of a semi truck, and another one tried to close the very small gap between the two and it didn't turn out so well for her.