SF muni-metro-modernization

 https://www.sfmta.com/projects/muni-metro-modernization

https://en.wikipedia.org/wiki/Muni_Metro

75 feet
(23 metres)  https://en.wikipedia.org/wiki/Siemens_S200 

https://en.wikipedia.org/wiki/Muni_Metro#Rolling_stock

https://en.wikipedia.org/wiki/Siemens_S200#Couplers

https://en.wikipedia.org/wiki/Market_Street_subway

https://en.wikipedia.org/wiki/Muni_Metro#/media/File:Muni_Metro_(2020-08).svg

https://en.wikipedia.org/wiki/Muni_Metro#Recent_expansions

https://en.wikipedia.org/wiki/Central_Subway_(San_Francisco)

https://en.wikipedia.org/wiki/Central_Subway_(San_Francisco)#Proposed_extension

https://en.wikipedia.org/wiki/Chinatown_station_(Muni_Metro)

https://en.wikipedia.org/wiki/Union_Square/Market_Street_station

https://en.wikipedia.org/wiki/Powell_Street_station

https://en.wikipedia.org/wiki/Yerba_Buena/Moscone_station

https://en.wikipedia.org/wiki/4th_and_Brannan_station

https://en.wikipedia.org/wiki/San_Francisco_4th_and_King_Street_station

https://en.wikipedia.org/wiki/Sunnydale_station