I've been down that road several times and never thought much about it. When I was a kid we lived in your town, Tucson. My Father would take us down to Nogales and the one thing I recall was a stretch of road like you describe, except it had wrecks scattered along the bottom of the cliffs every few hundred yards. I suspect that road is long gone now.
But on your DV road we pulled off at a scenic overlook and there was a guy with a player piano in the back of his pickup plinking away at the keyboad. I have some photos of it here somewhere.
Yup here it is: