Scheduled to arrive at SFO on 5/28/14 (Wed) at 3:30pm, meeting my college age son who is flying in at the same time to meet me. Option one is to pick up rental car at airport. I know we will not need it for three days in San Francisco, and will incur parking fees, but we will have it when we need it to leave on Fri evening for Calistoga. My main worry is traffic from SFO to Chancellor Hotel in Union Square on Wed. Option 2 would be to take BART on Wed and pick up our car downtown before we leave for Calistoga. My concern with this option is that if either of our planes are delayed, and we are late arriving at the BART Powell St. Station, we may feel unsafe. In addition, we will each have a suitcase and carry on to get to the hotel (I understand 4 or 5 blocks from hotel), especially if we are later than earlier. Need help with this dilemma!