[oman]

U.S. 1 is gorgeous, but by the end of a day -- and certainly by the end of a second day -- you'll be exhausted from the endless series of hairpin curves. (In my experience, at least, the part north of San Francisco is more tiring, but opinions may differ.) I'm not saying don't do it, just that when you reach whatever point at which you've decided to head east, you are not likely to shout, "Hey, let's turn around right here and drive back the exact same way!"

Yep.

Just make sure you have a sense of your alternate east bound routes back to the straight roads. 

[oman]

U.S. 1 is gorgeous, but by the end of a day -- and certainly by the end of a second day -- you'll be exhausted from the endless series of hairpin curves. (In my experience, at least, the part north of San Francisco is more tiring, but opinions may differ.) I'm not saying don't do it, just that when you reach whatever point at which you've decided to head east, you are not likely to shout, "Hey, let's turn around right here and drive back the exact same way!"

Yep.

Just make sure you have a sense of your alternate east bound routes back to the straight roads.