[midoridensha]

>2. The "arrival time" concept is a slightly odd.

There's nothing odd about it. Your arrival time entirely depends on the train schedule, and you can only arrive at your destination at certain discrete times because of this.

>I don't think anyone's going to use this to plan a specific route at a specific time;

I use Google Maps to do this exact thing all the time. I need to be at a certain place at a certain time, so I set the place and arrival time and have it plot a route and show me all the available options.