Based on this image, the Truck/trailer point of rest appears to be on the wrong side of the highway. Looking at the skid marks seems to substantiate that.
In addition, looking closely at the front end of the truck below, it appears to have significant front end damage. Based on this alone, there is likely a good chance this was a head on with the truck crossing over the center line.
However, there is also a possibility a motorcycle had crossed over the line into the trucks direction of travel, causing the truck to veer to it's left, over the center line.