Edge case: what if your phone does while in transit, and you can't charge it?

In the UK, the newer trains and tube carriages all have USB ports for charging.

But, it is kind of a non issue. You are responsible for your ticket. Having a dead battery is no different to losing your paper ticket.

iPhone NFC will work for a while even when “dead”, not sure about the android world.

But in the edge case of the edge case, security can let you out. If it becomes a pattern, they’ll note it somehow.

Seems like the most important thing to do is _anything_. The current approach of doing nothing and shaming people who suggest public transport is a poor option because it’s full of druggies doesn’t seem to work.