Then you are woefully underestimating the scale of what is involved here. At a bare minimum, you have to retrofit all of the existing trains and tracks with new hardware (getting rid of the old stuff in the process), upgrade the control center systems, not to mention training, testing and compliance. This is not a 12 month/$6m effort.

They already do some GPS-based train tracking (cf. https://www.sfmta.com/train-co...). They are spending what they are to install CBTC, which goes above and beyond just tracking trains. (https://en.m.wikipedia.org/wiki/Communications-based_train_control)

Floppy disks are just one part of the grand scheme of things; the point is that they're upgrading the train control system (cf. my above comment), and getting rid of floppy disks is an added bonus

Induction loops are old school - they are moving to CBTC (as they should be if they're spending $212m on it!)

Personally I think that the fact that floppy disks are still being used receives unnecessary focus (per the SFMTA's own words, this is 1980s tech installed in 1998, what do you expect). The more salient point is that (per https://www.sfmta.com/projects...) they are upgrading the existing train control system from the older ATCS (subway only) and manual control (everywhere else, and when ATCS comms fails) to CBTC - this allows the control center to know much more accurately where trains are at any given point in time. This article from 2019 (https://medium.com/@SFTRU/muni-metro-train-control-challenges-5985b0e4912c) is a good overview of what the issues are; the author clearly got his wish, because CBTC is exactly what is happening (-: