This driver was driving rather slowly and I saw a tractor trailer try to pass them and they decided to speed up. I chose to pass them in another passing zone and as I drove by they continued to speed up and not realizing how fast we were going, I looked down and it was close to 90 mph so I wouldn't pass them. They flipped me off as I drove past them. They passed me in the next passing zone and continued to flip me off the entire time. They were driving like a complete idiot