I can think of two kids on motorbikes killed by these kinds of trucks on stretch of road in Chiang Mai. Those two accidents were trailers and the kids get stuck between the two sections, maybe saw a gap out of the corner of their eye and moved in to it.
Thai people are too conformable driving extremely close to each other. This girl like most people would just casually drive along side it and not think anything of it. RIP.
One of the very few times I ever got hurt on my road bike one of those very long bedded trucks passed me and slowly started to push me off the side of the narrow 2 lane road. Got very close to having to jump off into the irrigation ditch. I got so angry I drafted him for a couple of kilometers and found him parked at a bar, and yes he was visibly drunk even. Maybe the only time I ever yelled at a Thai person but nothing came of it because he knew he was drunk and driving.