Oh, and the (Siemens, at least) trains also take like 30 minutes to boot up. And rebooting a train is often a way to fix problems. So delays can happen because

Oh, and the (Siemens, at least) trains also take like 30 minutes to boot up. And rebooting a train is often a way to fix problems. So delays can happen because a train is sitting on some important piece of track while rebooting. This reboot time sounds absurd until you hear the tech stacks running on these trains. I don't remember the details, but it was real Rube Goldberg stuff. Something like System 7 code running on a soft PLS because the real PLS is EOL but the soft PLS can only run on Windows 95 so you run a virtual Windows 95 on top of some obscure hypervisor, and I think there might be another layer to the story as well. Just anything to avoid changing the actual code that runs the train because that would trigger a recertification process.