Each block can have double track, to allow extra throughput. A block of double track will allow two trains from opposite directions to pass at the same time. I know that a lot of people like to go deep into the micromanagement of signals and track switches, but I hope you will also enjoy the higher level approach that I am attempting.
Tracks are designed by dragging them across the map. Track can not cross steep terrain, but this can be improved through research. When the track is designed, a specialized track-laying train will go to the unbuilt track and start building it. I thought this was a fun little visual feature to have, and I always liked to the idea of being able to design things in a game before building them.
The station is where most of the meat of the game happens. Industrial facilities can be built within the range of a station which is currently 2 tiles. Output of these facilities are stored in the station, and input is taken from the common station storage. Each facility requires resources to build. When the order is given to build a facility, an idle train will transport the needed resources as soon as they are available.
The autonomy of trains is of course the main theme of the game. As the player, you will direct where resources should be transported to, which things should be constructed, and what research to do. Most of the time there will be no need to dispatch individual trains, although the option is there if you want to. I want the stations, facilities and trains to feel like a single autonomous entity, partly doing its own thing.
A game in this genre needs a research system. Resources must be transported to the starting station to progress the research. Exactly which resources are needed depends on the active research project. This approach will create a bottle neck in the central part of the railway network. I'm still not sure whether this should be a challenge for the player to overcome, or if research should unlock decentralized research hubs.