California Coast Drive

It's only a mile or so and it's on Geary Blvd which in that area is mostly four lanes. There's plenty of room for an RV. Take a look at it on Google earth. You vear off on Pt Lobos Ave and then you hit the ocean right at the Cliff House. Once you come down the hill past the cliff house is Ocean Beach which has a big parking area. There may be room to park an RV there for a while, depending on if you're there on a weekend or not. If you can't find a place there, it you take a left on JFK Blvd into Golden Gate Park, there is usually street parking available on JFK drive and at least last time I was there, there was no time limit and it was free. So you could leave the motorhome there for a while and explore in the toad. Otherwise if you keep heading South you come across Fort Funston. They also have a giant parking lot where you may be able to leave your motorhome for the day while exploring in the toad. And that is also very close to the zoo. All of these places will be pretty crowded on weekends in the summer, and mildly crowded on weekends in the other times of the year. You should be able to find room on weekdays.