I did see a quote from representative from NAPA county saying that it's goiong to be 45 minutes in traffic for three years. Where the number came from was not explained. could very well be a random comment.
Here are links to a couple articles:
Use your favorite search engine using the phrase "Sausalito: Doyle Drive construction project" and you'll get a passle of informative links. Go beyond the first page of returns, note that even your query is included.