Hello guys, I am totally newbie in graph databases, I saw several tutorials and I asked couple of days ago for help with cypher query. Then I realized that my data model is not optimal, and I should design a new one by myself for my needs. Right now I am using PostgreSQL for storing data, I came out from GTFS standard, and customized it a little bit. I added platform_number, runday and distance from last stop to stop_times table.
Here is my ERD:
Why I need a Graph database?

I want to search for indirect connections between 2 stops with a transfer node.
a) shortest path based on time (fastest)
b) shortest path based on a distance between stations 
In SQL database I am able to find only a direct connection of one trip. No transfers, and performance is a little bit slower in bigger amount of data.
I found some work of Bruggen where he loaded data into neo4j (link), but to write optimal query over this model for getting outputs is complicated for me. So I think to write a translator for my data if I found an optimal graph data model with your help.
Model created by Bruggen, which I tried:
Output wanted from Graph Data model:
a) Find the shortest path between 2 stations which don't have a direct connection by train.
b) The Shortest path is possible to count by travel time and distance between these stations.
c) The Query will return me Station A (from) Station T (transfer) Station B (to) and trip_id of connection between these stations.
Thanks a lot for your help.
~Martin