Discription of Events: This truck slowed down at a commonly-disregarded yield sign on Highway 15 just next to the old BP gas station, to its credit. However, that slowdown was only for a second, and the truck proceeded to pull out in front of me despite the fact that I was going the speed limit (55) and was less than 100 feet away from the yield sign. The truck proceeded to go far below the speed limit all the way into town.