Ah, I cannot express enough the fear instilled in me on 340. I actually had a panic attack, and that was before the worst of it. I also hyperventilated. They should warn you about this before entering, because we had no idea what we were entering!!! Funny the "one lane" bridges were actually bigger than the normal road ways!!!! I must admit I have a fear of heights, but this has been by far my very worst experience...I've also traveled Hwy 1 in California to San Luis Obispo from San Francisco and that was bad but still did not compare. Watch out and if you decide to enter hell, have a VERY experienced and safe driver please.