Shoulder Speeder

Today a first happened to me while I was driving. No, I didn't get in a accident, get a ticket, or run someone over. I was driving home from college, in the right lane of a two lane highway. I heard a car accelerating quickly behind me, I thought it was maybe a motorcycle. Before I could even look in my mirrors and see what it was, I was getting passed in the shoulder. Yes, a car went around me while I was in the right lane on my right. I guess they decided to make a two-lane highway into three lanes. I am not quite sure why they did this. It wasn't like I was going slow or anything. They passed me like I was standing still. Thankfully for them, I drive in my lane and don't swerve into the shoulder. It was quite stupid of them, not to mention dangerous.