What's the method for finding train connections?

Question

I have looked at the data examples for GTFS. I want to be able to find a method or logic to finding train connections.

For example. We have three train station: Big_City_Station (which is a huge destination) Mid-size_Station (a large hub - transfer point) Midway_Station (a hub 20 miles from Big_City_Station - transfer point) Home_Station (A suburb where the trips begin each morning)

There are several train routes which leave from Home_Station. Let's call them primary and secondary. Primary and Secondary almost always stop at the Midway_Station. In order to get to the Big_City_Station we start at Home_Station and transfer to make the connection at Midway_Station to hopefully catch a train to Big_City_Station.

What is the method to make the transfer points be the most efficient? Is there an algorithms for getting from point A to B including the transfer stations? Or is the programming solution simply only this: Check Home_Station for next train that stops at a transfer point and get the train times to make connections, if there isn't a train trip available without stops from Home_Station to Big_City_Station? Thanks!

Answer 1

Your best bet is probably to use an existing transit routing engine (https://github.com/openplans/OpenTripPlanner/wiki or http://graphserver.github.io/graphserver/), for example.

There have also been some papers on determining the transfer patterns in a transit network. You might check out Fast Routing in Very Large Public Transportation Networks using Transfer Patterns: http://ad.informatik.uni-freiburg.de/files/transferpatterns.pdf