the new cars was delivered in November 2017 with plans to finish the replacement of the entire fleet by 2027. This train procurement, in addition to replacing cars on existing lines, was made in order to supply the additional service required for the Central Subway and to the Mission Bay neighborhood and Chase Center. Throughout the 2010s, Muni also procured new buses and replaced over 90 percent of its diesel bus fleet and replaced all of its aging trolleybuses, improving performance for its bus fleet. 2020s Amid the COVID-19 pandemic, ridership numbers had dropped 70–90% across the system. Muni Metro services, with an over 90% decline in riders, were replaced by bus bridges on March 30 to streamline sanitation procedures. By April 6, service had been eliminated on all but 17 of the agency's then 89 routes with San Francisco Municipal Transportation Agency Director of Transportation Jeffrey Tumlin calling it "the worst Muni service since 1906." Light rail service resumed briefly in August 2020 with significant route changes, but was discontinued and replaced by buses after just three days of operation (August 22–24) because two overhead wire splices failed in the subway portion of the line within 72 hours and an employee in the system's control center tested positive for COVID-19. The splice failures in 2020 meant that passengers could be trapped for an extended period of time in an enclosed light rail car during the pandemic. A similar splice that failed in April 2019 in the Market Street Subway between Powell and Civic Center disrupted services system-wide for more than 12 hours, and led Mayor London Breed to seek a replacement for Muni head Ed Reiskin. Metallurgical analysis of the failed splices (including the failed splice from April 2019) showed the materials did not meet their specified tensile strength. Some additional bus routes have started to be restored throughout Fall 2020 and into 2021 to address overcrowding and increasing ridership including new short routes on the 1-California, 5-Fulton, and 14R Mission Rapid. On September 19, 2020, the 30-Stockton was extended to Sports Basement in The Presidio to accommodate longer, 60-foot buses along the entire route. This change resulted in many complaints from Marina District residents who complained about parking removal and low ridership along the extension. On December 19th, 2020, light rail service resumed on the J Church on a surface only route. Light rail service at the T