I am brand new to the General Transit Feed Specification (GTFS) stack and subway calculations and I'm working on a project where I need to tell a user what the best route / line to take based on their current location and the destination latitude and longitude.
I've done some googling and see some good ways to find the closest subway based on current location, but I'm at a loss as to what to do to get the path to the destination if let's say they have to take multiple lines to get to a destination.
Can some one give me some guidance and possible tutorials?