These trucks always traveled in pairs of 2 or 3, so that if one got stuck it could be pulled out. It's also safer to travel in a pack when it's raining and the mountain is even more slippery.
This is my retro website, a homepage that dates back to the day when the Web was still coded with text editors, well-worn keyboards, elbow grease and Unix servers... the guts all neatly hidden from sight thanks to hyperlinks.