If OP's subway carried 80k people per day (and I guess this could be conservative), and they are all delayed 15 minutes, the overall wasted time equals 1 lifetime per month.
I'm all for improving the technology, but in the meantime the math should absolutely be done, at least to ensure the temporary fix isn't worse than the problem.
Jokes aside time spend on the subway isn’t actually equivalent to time spend dead, we shouldn’t trade them one-for-one.
Also the “one extra death per century” measure seems to be derived via the method of rectal extrication, we don’t know how many deaths a schedule change might cause or prevent at all, and I bet the people working on the subway have, if anything, some idea with massive error bars.
I dunno the math seems basically impossible to do, I mean it would have to include things like “how to people, possibly irrationally, respond to deaths on the subway.”
There are feedback mechanisms here which shift where people live and work in response to changes in transportation times. Which means you can’t simply extrapolate like that over time.
You need to adjust for the QALY level of riding a train compared to the rest of people's lives. Train riding isn't much fun, but it's much better than being dead.
Is it necessarily wasted, though? If the subway is tedious and unpleasant, then sure. But if I get a seat and I get 15 more minutes reading or staring out the window, then I’m probably not calling that a complete waste.
I'm all for improving the technology, but in the meantime the math should absolutely be done, at least to ensure the temporary fix isn't worse than the problem.