Brilliant !! TIT at it's best! As you say, an important juction feeding several villages and communities out there in the sticks. We use it every time we go to the city from our place near Muang Pho. It was only fairly recently they built a dedicated turn lane, and that made the juction a lot safer imho, as it was always an accident waiting to happen. What about the roadside rescue car that sits at the junction? Effectively cut off!!
Even with the turn lane it was still a dangerous junction, but forcing people to make U turns is not the solution.