I've started a document of services you can run across two or more routes in TSW. It's very much a work in progress, and has just started, but you may find it interesting! https://docs.google.com/document/d/1feG0Emoe0gbbn8BrZ8FPRp9W_lHO1oCgbQEYz4QOusE/edit?usp=sharing Let me know what you think and if you have any services to suggest
The East Midlands Trains 158 services on MAC (from Picadilly to Stockport) and ECML (Grantham to Peterborough) are both part of the same Liverpool Lime Street to Norwich services
Great idea! For near perfectly linked services between Frankfurt Fulda and Kassel-Wurburg, check out noir's list in the Awesome Services pinned thread. Some of those can be done with a route hop at Fulda. Frankfurt S-Bahn has also created opportunities for PC users to do two route hops for services from Wiesbaden. For the US there are definitely matching Amtrak services for Boston-Providence and New York-Trenton . I'm also not certain but it may be possible to do a freight run on Antelope Valley and then continue it on San Bernardino followed by Cajon Pass which would be hours of driving! You can certainly drive a Metrolink on Antelope Valley and then do a San Bernardino service. Obviously that's not the same train but does give you a big connected world to play in. In the UK the Mildmay Line with it's multiple route hops provides some interesting possibilities to connect journeys.
Definitely not stepping as this is a considerable expansion of the idea. Just thought I'd offer some suggestions.