How do residents get bicycles to the Amador Causeway on weekends?

I am writing with a practical question. Our household moved here recently and we would like to spend Sunday mornings outdoors on the bicycles. Traffic at rush hour on weekdays is very heavy, and I do not yet know whether weekends are similar. Do residents usually load the bicycles in a car and drive to the Amador Causeway, or is there a sensible way to ride there from the city?