was heading South on 301 in the left lane behind an SUV and in the right lane was a pickup, a box truck and then this semi (Garrison Transport Mission, TX). The pickup was going fairly slow so the box truck (safely) changed lanes and got in front of the SUV. The box truck was running right along side the pickup (passing), the SUV was directly behind him and I was directly behind the SUV. The semi driver speeds up and runs right up behind the pickup then turns his blinker on. I suppose he thought the SUV driver and I should have hit our brakes to let him get over and when we didn't we swerved into our lane then back in to his. The SUV driver and I both had to brake and swerve onto the shoulder to keep from getting hit. The semi driver took that opportu