My reading: There is A-C-A contract. Both A-B-C and A-D-C routes are possible but the game insist on passing B in both directions: A-B-C-B-A. Your wish is to pass B only once and have A-B-C-D-A.

When accepting the contract it is possible to add D as waypoint between C and A to tweak the routing.

引用自 Mišo：

When accepting the contract it is possible to add D as waypoint between C and A to tweak the routing.

How do I add those waypoints and/or delete other waypoints?
I just have a similar problem: Trains from A to D could go via B or C (Hamburg map: trains from Hauptbahnhof could go via Sternschanze or Landungsbrücken). The contract only shows me the route via Landungsbrücken, while I’d want to go via Sternschanze.

It is something we are considering rather than something already in-game.

I have a similar issue with urban transit timetable planning. With urban transit contract I can select the stations I want to serve, but the contract always adds an unselected station.

I have stations in all geographical directions and one central station which connects all of them. I have also a direct connection between the south and the east station. I tried to create a urban transit contract starting in the south station going directly to the east station and then far more to the east. But this contract always adds the central station to it, even I didn't select it.

Is there a way to avoid this? Because it is a detour from what I planned and the central station is already heavily used and I don't want to stress this track even more.

Me again: As soon as you can, opt for “user defined contracts“ (or similar, am playing the German version). With those you can set all in-between stations as you like!