In 2004, Muni promised a fully zero-emissions fleet by 2020. But the battery-electric bus market was slow to mature, and the agency wasn’t comfortable buying buses that weren’t yet guaranteed to last, given the agency’s 700,000 pre-pandemic daily boardings and the city’s terrain. That may change when Muni begins testing three buses each from three of the major battery-electric bus manufacturers later this year. In the meantime, the agency is also buying 30 small hybrid buses that can navigate neighborhoods with tight turns and steep hills.
Agencies across the nation joined San Francisco over time to deploy hybrid buses to reduce their carbon footprint. While some agencies, including San Francisco, continue to buy hybrids, often as a stepping stone to electrification, other agencies have encountered maintenance challenges and decided to change course.