You might like to just use the initial letters for the stations.
Remember that at Barkton and Cheston you can either go straight through on the same line or cross over to the other line.
For example, you can be coming from Zogborough through Barkton to Xanly or you can be coming from Zogborough through Barkton to Worsby.
How will you know you've got all the routes?
Will you need to record the different routes in some way?