I've done the drive on Hwy 1 from SF to LA. My advice: check the weather forecasts very carefully. If it's sunny, it's a stunningly beautiful drive. If it's rainy and foggy, it can be a nightmare. Once I found myself stuck going at 20 mph on a twisty road with zero visibility and nowhere to stop for about an hour, while it was getting dark. It was far from enjoyable.