I’m assuming you’ve never ridden mountain roads out west? And are not aware of how extensive the ‘guardrail’ would have to be? Those roads are built into the mountainside, narrow lanes, sharp curves, with no room for error, straight down drops of hundreds of yards. Sure put this easterner’s heart in mouth. Spectacular views, tho.
Oh, sure, they can’t guardrail the whole thing. But this must be a bad spot, if two cars went over in the same place.
I remember driving along the French Riviera many years ago, and they only had selective guardrails. That was pretty scary, too, especially if you met a bus coming the other way. But great views.
Actually the dirt roads in our vicinity here in Vermont have similar problems, if not so dire. Deep drainage ditches where the car is certain to flip, and steep downhill verges. They can only afford to put guardrails on the worst bits, but that’s better than nothing.