These are the
addenda for Pacific Coast Map 4, which contains the Highway 1 outage. If you dig down, there is a recommendation to divert inland at Monterey, and go back to the coast just south of Cambria. I live in San Jose, so when I go in mid-April, I will be following secondary roads like highway 25, go through San Luis Obispo, and then continue on the coast. You can use Google maps to recommend a bicycle route, but be mindful that there may be no services for long stretches. I plan to carry a full day's supply of water, and 2 days of food.
Note that San Francisco Airport is not actually in San Francisco, but about 20 miles south of the city. If one is flying into San Francisco Airport, one would be backtracking if they wanted to see the actual City, and that would not be a particularly scenic ride.
If one wanted to get to the coast, straightaway, the best move might be to hire a taxi, Uber, or Lyft to take them and the bike(s) via highway 92 to Half Moon Bay. As a local, I'm somewhat familiar with the mountain roads and how to get to the coast, but I wouldn't recommend it to someone from out of town. Further south, there are other ways to the coast. Kings Mountain/Tunitas Creek road, popular among tough cyclists, but VERY (15% if memory serves) steep in places. Highway 84, not as steep, but still steep. Highway 9, further south, gentler still, with an average grade of 6%. And the easiest way to cross the mountains in the area is Soquel - San Jose Road. But remember that you'll be cutting over to the coast for the benefit of 1 to 2 days of scenery (admittedly beautiful), before being forced back inland for the detour.
The other choice is to bike via frontage roads for highway 101. That's a reliable path, full of services and lodging, but not scenic, as it is basically urban/suburban area for 40 miles, then maybe another 100 miles of central valley farmland and gas station towns. No ocean. But it does pass somewhat near my house in San Jose, and anyone going through the area before mid April is welcome to stay over. Not fancy - you may need to roll your sleeping bags out on the floor, but we'll make it work. Email or message me if interested. Another benefit of the 101 frontage roads is that one could pick up the official detour in the addenda at Salinas.