While I’m happy to hear that the map size is going to be large, it will never be large enough for some people. Myself, I love the deal of building something realistic-ish, and 16km on a side is barely one good-sized metro area in real life.
But! That doesn’t mean that 256sq km is a bad map size! In fact, it could be great! Here’s an idea: cargo/passenger loads coming in from, or demanded by, the edge of the map.
It could work in such a way that tracks could be drawn off the edge of the map, and that ‘endpoint’ added to the train’s orders. This would allow us to simulate long-distance travel in and out of the area we’re playing. It’d be great for giving us the feeling as playing as a part of a larger world!
Just something to think about.