He got way ass up there!
What keeps the the trucks from rolling backwards down the hill?
I'm gonna go out on a limb here and say "the transmission".
Back in '96 or so, the (not yet) Mrs. and I caught a fortuitous day, where they allowed motorcycles to go up the Mt. Washington Auto road (elevation 6,400 ft). We went up in this
which wasn't exactly an all-purpose vehicle.
The road looks like this.
You'll notice a few things:
- It turns into a gravel & dirt road;
- It's always fogged-in (causing dangerous conditions).
The whole way up, I just kept praying (to myself) that the clutch didn't burn out, whereby we'd roll backwards to our deaths. But coming down was awesome - I just kept it in 2nd gear; no throttle, no brake. All the cars had to keep pulling over because of brake overheating.