The San Francisco Municipal Railway (Muni) is the primary public transit system for San Francisco, California. Muni is part of the San Francisco Municipal Transportation Agency, which is also responsible for the streets, parking, traffic signals, and other transportation in the city. In 2019, Muni had the eighth-highest ridership among systems in the United States, with an average weekday ridership of 684,600. Service is operated to all parts of San Francisco - including Treasure Island - as well as small sections of Daly City and Marin County. Muni operates seven light rail lines in the Muni Metro system, two streetcar lines (E Embarcadero and F Market & Wharves), and three cable car lines. Daytime bus service includes 44 local routes, 5 limited-stop "Rapid" routes, and 15 peak-hour express routes. Four additional express routes provide weekend service to the Marin Headlands, service to Oracle Park (home of the San Francisco Giants), and the Chase Center (home of the Golden State Warriors) and supplement BART in the early morning. Overnight night bus "Owl" service - part of the All Nighter network - includes eight 24-hour routes, two night-only routes, three bus replacements of Muni Metro lines, and five-weekend early-morning Muni Metro replacement lines. Fourteen local routes (two only at certain times), one rapid route, and four Owl routes run as electric trolleybuses. Muni service operates out of ten yards and garages: one cable car barn, three light rail/streetcar yards, two trolleybus garages, and four bus garages. Routes have two-part names like "19 Polk" and "N Judah", where the second portion is usually a street served by the route (or in some cases, a neighborhood or landmark). Light rail and streetcar lines are lettered, while bus routes are numbered. The letter/number scheme was created by Muni, while the two-part naming scheme was created by the Market Street Railway, which Muni absorbed in 1944. The three cable car lines are largely known by name (Powell-Mason, Powell-Hyde, and California), though they are abbreviated to PM, PH, and C on maps, and have internal numbers 59–61 for operational purposes. Muni began service on December 28, 1912, when the A Geary-Park line was inaugurated, running between the Financial District and the Richmond District on the western side of the city. The streetcar system was expanded over the next 16 years, including the Stockton Street Tunnel in 1914, Twin Peaks Tunnel in 1918 and the Sunset Tunnel in