Specifically, the safety upgrade is about detecting someone that walks into the area between two railcars.

I think it should be said, though, that this is far from a standard feature. You don’t fuck around with trains, period. You stand behind the line, wait until they come into the station, get on, get off, then leave. You don’t walk over the tracks. You don’t climb over or crawl under them. And you don’t walk between them.

Could this directly save a life? Yes. What are the other consequences? Well, it makes public transit more expensive. It also adds an additional point of failure to the system, resulting in more potential for delays (the train has to stop if the system flags a false positive). Which means, the train is less attractive. What happens when trains or public transit in general is less attractive? People go by car instead, which is a much, much more dangerous mode of transportation, it’s not even close, never mind the sometimes deadly effect of pollution. So in total, it might actually take more lives indirectly than it saves directly.

You can spend all the money in the world making trains or even transit in general as safe as possible, and you’ll still never be 100% safe, and you’ll have no money left for anything else. At some point, you have to prioritize.

Note the safety upgrades were only considered after the first time someone died.