in my bc wanderings i always try to get pics of these warning signs, which are located at the top of the steepest grades... note that the speeds are in km/h, not mph
here is a runaway lane on the coquihalla pass (8% grade for 13kms, no flat sections):
the road i still long to experience is the drop into bella coola, down the heckman pass... 18% grade for 6km, with no flat spots, no runaway lanes, no roadside barricades... the road can never be paved because only gravel provides enough traction to climb or slow down on the damn thing.
note how steep the section these folks are standing on is: