After loading the pigs, he stops at the Marker 126 truck stop on Highway 20, just east of Ft Dodge.
It says they can see him on video there and he's there for 16 minutes.
What's interesting is that then they say his cell records show he then goes straight to old 71, where they find his truck the next day.
Very possible they aren't releasing all information, but it's strange if his cell location doesn't show that he turned south off 20 toward Sac City first, and then stop/turn around.
Makes me think that someone got in his truck with him at the truck stop.
The roadblock theory doesn't work to me in this scenario. I feel like that scenario would have had to have happened on a gravel road, or highway shortly after he loaded the pigs. Even that late at night, highway 20 would be too busy to do something like that.