Chronicle: S.F. Muni approves $212 million technology to replace floppy disks

San Francisco transportation officials moved a step closer this week to modernizing the train control system that runs the Muni Metro system, eventually ridding it of a system that uses outdated technology and runs on floppy disks.

I wanna know what’s on the floppy disks

The software that runs the system is stored on floppy disks that are loaded each morning and an outdated type of communication using wire loops that are easily disrupted. It was expected to last for 20 to 25 years, according to Muni officials. It moves data more slowly than a wireless modem, they said.

I’m afraid it’s not obvious to me why the train has to move data more quickly than “a wireless modem” (very vague). One imagines the position of a train doesn’t change too rapidly or unpredictabily, are there more data streams that they want to send out they’re not able to now?

While the current train control system operates only on the Market Street subway and Central Subway, the new system will control Metro light rail trains on the system’s surface lines as well.

This does seem like a good thing. I imagine they can’t really have something like PTC on a streetcar system in mixed traffic, but if there was missing operational data before adding it is a good thing.

https://www.sfchronicle.com/sf/article/muni-board-approves-new-train-control-system-19846976.php