I've been on those roads a number of times. They are dangerous at 50, much less 70. Idiots. This borders on Darwin award territory.
Idiots.
Only one of them was driving. I guess well never know if the others complained about the speed.
I cant even imagine going 70 mph in a 15-passenger van down a dirt road headed for a bridge, and Ive done some pretty stupid things in a moving vehicle.