[seanmcdirmid]

Wiki says it was more because of the private right away used, not necessarily its steepness:

> While many streetcar lines were converted to bus lines after World War II, the J Church avoided this due to the private right-of-way it uses to climb the steepest grades on Church Street, between 18th Street and 22nd Street.[9]

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

[fotta]

> Ironically, this steep grade saved the J-Church line from being replaced by buses. After World War II, San Francisco began replacing the streetcar lines with buses, but the Church Street hill proved too steep.

Little bit of columns A and B

https://www.opensfhistory.org/osfhcrucible/2019/08/10/the-j-...