There were a grand total of 50 homicides on U.S transit in 2022. The number of deaths from drivers was 42k that year.

This is not a serious concern, and it's telling of the mindset of drivers in the U.S.

I am a great deal more risk of being killed by a driver when I walk than I am being murdered on a train.

Especially as Waymo program their death machines to blow through pedestrians at crossings 70% of the time.