I paused the video, and it looked to me like it was just an ordinary, albeit long, flatbed gooseneck trailer. Around here, I'd guess it would be an oilfield hauler, but it could've been for hauling lots of things (I think they said in the video that it belonged to a hauling company).A pickup and trailer caused the wreck. From what I saw on the evening news, the trailer looked like an in-line round-bale hauler.
One thing is for sure--that truck had too much trailer and not enough driver.