Semi trucks in both lanes.
To our defense a lot of company trucks are governed at a certain speeds. No two companies are the same. Then there are some of us who own our own trucks and like to drive faster. Passing another truck after having to hit the brakes sometimes takes a minute. It's pretty difficult to get 80,000 pounds moving and you darn sure aren't going to do it very fast! Especially if the road goes even the slightest bit uphill. But I will also say some truck drivers are just ......... ok well a lot of them. But still! lol