For Amerian drivers who are used to driving on the right side of the road, nothing could me more terrifying than learning to drive on the left. Our first encounters with this were years ago when we used to take a long weekend in the fall and go to the Grand Bahamas where, thanks to British heritage,you have to drive on the left side of the road. We giggled a lot about the big label pasted on the dashboard that said "Keep Left!" but it was a good reminder.
Since those early days we've learned to navigate from the other side of the road in Ireland, New Zealand and Australia. There were however, some terrifying moments. Our first trip up the mountainside just outside of Cairns, Australia, to get to the village of Kuranda in the rainforest was from my view in the passenger's seat, death-defying.
Actually the trip up wasn't bad. We were mostly on the inside part of the road with trees and forest. We explored the village, enjoyed the Aboriginal exhibits, got our souvenirs and headed back down. By that time the light was fading and shaded by the rainforest canopy. This time my view was a sheer cliff most of the time that rose above the valley below--way below. Every time we rounded a curve Bob would give a little space in case a car was coming from the other direction and I would give a little scream because I was sure we were going over the edge.
Several years later we made the trip again. This time I made sure we planned to be back before the light faded. If we were going over the edge, I wanted some daylight for the rescue party.
Curiously, an article on Smarter Travel.com lists ten roads they consider terrifying and Kuranda didn't make the list. There were a couple mentioned in China and while we never traveled those, I would think that many roads in China would be terrifying in that there is so much traffic and hundreds of bicycles with whole families perched on them navigating through the cars, trucks, and buses. A sight to see. And at the least, frightening.