Discription of Events: I turned and merging onto UT-112 when it was clear. The car behind me decided to merge to. At this point I’m already merged and in the one lane headed to Grantsville. The truck then decided to gun it and whip right in front of me at the end of the merge. Note there was plenty of space behind me for the truck to merge. I had little time to react, one second there is nobody in front of me and the next I know the truck pulled out in front of me and started to break.