Basically, I was on the road right before I merge onto the highway for work. It's a straight ish road, 40mph speed limit. I had maybe 10 cars behind me, the van in front of me was going like 38..way to slow. Going down a hill, he turns on his signal to go left and slows down. I assume hes making his turn, but then he keeps his signal on and continues to drive down slowly, randomly stopping and peeding up again. Finally he stops, peeks his head out the window, then sticks his arm out the window and does the motion for go around me. I start to go around him, and he then makes his left turn, (I was passing on the left, one lane road) and I slam the brakes not to hit him, and since im in the old wagon, it has no abs, so the brakes lock and I start slidiing towards him. Missed him by maybe 3 inches. He made his turn, I sped off. IDIOT!