With five different modes of transport the San Francisco Municipal Railway runs one of the most diverse fleets of vehicles in the United States. Roughly 550 diesel-electric hybrid buses, 300 electric trolleybuses, 250 modern light rail vehicles, 50 historic streetcars and 40 cable cars see active duty. Muni's cable cars are the oldest and largest such system remaining in service in the world and its fleet of electric trolleybuses is the largest in the United States. In 2020, Muni completed the process of replacing its motor coach fleet – the first of which was procured in 1915 – with diesel-electric hybrid buses. Fleet overview This chart is a summary of the vehicles currently operated by Muni. All buses are accessible at all stops. All streetcars are accessible; however, some surface stops on the E and F lines, and many Muni Metro surface stops, are not accessible. Cable cars are not accessible. Facilities Bus fleet , Muni operates a fleet of roughly 550 diesel-electric hybrid buses and 300 electric trolleybuses, consisting nearly entirely of New Flyer Xcelsior coaches which have a high degree of parts commonality. The only non-Xcelsior coaches are the battery-electric test buses and the "community route" buses which were built by ENC as New Flyer does not offer a short Xcelsior coach. Diesel-electric hybrid buses Muni's active diesel fleet contains coaches ranging from thirty to sixty feet in length. All of Muni's current buses are diesel-electric hybrid buses, fueled with renewable diesel fuel made from bio-feedstock sources, including fats, oils and greases. The diesel-electric hybrid technology has proven very capable of climbing San Francisco's steep hills. Before 2007, Muni had an all-Diesel fleet that had been purchased from three manufacturers, NABI, Neoplan and Orion, all of whom no longer sell buses in the U.S. (NABI merged into New Flyer, Neoplan left the North American market, and Daimler shutdown Orion), making repairs challenging. After purchasing its first hybrid buses in 2007, the agency embarked on a nearly 15 year project to replace the entire fleet. The new fleet has averaged more miles between road calls – in which a mechanic services a transit vehicle on the street – than the prior diesel coaches. Electric trolleybuses Muni's fleet of electric trolleybuses (ETBs) is the largest in the nation and serves many parts of the city. ETBs were very popular in the United States in the middle of the 20th century.