Creating our own real environment

Hi!

Since OMSI was announced to have an user-friendly route editor (like MSTS) I had the idea of making a map of the city I live, and I think now is a good time to start with it. So, I know I can put in the route some background images which allow me to don't put streets wrongly, but...Do I need to create just one huge image file or a lot of squared image file of 300m side? Or another way to ask this...can I set a general background image or have I to set it tile by tile?

I have another question but this one is only for knowing it if I need to at any time. Here, in the area I live, suburban and intercity buses can sell tickets in route, but the price depends on the distance and the route itself, so...it's even possible to script this? I mean, in programming terms, to create a 2-dimension array (like a matrix) with origins in 'x' side, destinations in 'y' side and prices relating 'x' and 'y', so if I change origin and destination, the machine tells me what price does the ticket have? This would have to be applicable to some different types of tickets, so with a defined origin, destination and rate (only trip, go and return trip, young discount, elder discount, kids, etc.), the ticket machine has to show me the correct price...

I don't think you can understand me (the above paragraph is a complete mess), so I there's anything not understandable, please tell me.

Thanks in advance!