Discription of Events: 2 lane traffic pattern. I was in the right lane going right at speed limit. A truck was in the left lane next to me, slightly ahead of me. The driver of this Pontiac Montana comes up on the truck at a high speed and then immediately cuts to my lane with no clearance to do so. I slam on my brakes to not get him. He then proceeds to drive 10-15mph over speed limit weaving in and out of cars.