While it’s not actually part of Hwy. 1 (but is Hwy. 1 adjacent), I had an an experience like that driving up Muir Woods Road from the Muir Woods to Panoramic Hwy. That’s a similarly steep, curvy, climb with no guardrails and a steep drop off on one side. I had a brief scary moment due to attempting to admire the view while also driving, almost didn’t notice a curve coming up, and… “OH SHIT! WATCH THE ROAD!”