The BSicons are similar to the network tiles used in SimCity 4. The main work of transit modders there (Network Addon Mod) is to create additional tiles for different types of transit intersections.
It would be very interesting to see one of the OSS city builders pick up BSicons as a subset of their schema.
There's a couple of train simulators I enjoy playing with on my downtime, and this seems like it might be an easier path towards making a highly complicated engine for something like that.