(These days, you could also replace the floppy with a USB drive: they make adapters/emulators.)
> Turns out that in 1998, SFMTA had the latest cutting edge technology when they installed their automatic train control system.
> "We were the first agency in the U.S. to adopt this particular technology but it was from an era that computers didn't have a hard drive so you have to load the software from floppy disks on to the computer,"
The fact of when hard drives became commonplace in personal computers (EDIT: or when 3.5" floppies were introduced) has no bearing whatsoever on whether this transit control system was cutting edge in 1998. This statement is not, at least not obviously, factually incorrect. So if you're going to claim that, show your work.
The other good thing about the floppy is it can't hold very much code. So the system has a tight upper bound on how bloated and complex it can get. Simpler systems are more maintainable.
These things seem like great assets for maintaining critical infrastructure.
EDIT: Another great thing is such a system will be stateless. No disks, no filesystems, no databases. Sign me up.