San Francisco is the most densely populated city in California, with over 17,000 people per square mile. It has a diverse public transportation system that includes Muni buses and light rail, BART subway, Caltrain commuter rail, ferries, and the iconic cable cars. Over 30% of San Francisco residents use public transit for their daily commute, ranking it first among West Coast cities. The city also has a large number of people who walk and cycle for transportation each day due to its compact size and transit accessibility.