People who don't know how to merge

You know what grinds my gears? People who do not know how to merge.

Seriously? You didn't see the giant sign that said your lane was ending? So instead of just getting over, you push to the front and make a traffic jam. Nice job idiot. This slowed traffic could have been prevented if you had taken the time and slowed down to get over. But no, you decide to push in front of all the cars that did the right thing by merging and now you want to get into our lane. I don't think so. I don't have any qualms with not allowing you in.

And that people is what grinds my gears.