If you do not wish to automatically load a journey when selecting a route from the main menu, then you will need to disable "Auto Load Journeys" from the settings menu. You can access the settings menu by pausing the game and holding the L1/Left Bumper button to show Options.
How to disable "Auto-load Journeys"
- Open Train Sim World 2
- Go to Settings, Game
- Scroll down to "Auto-load Journeys"
- Change this option to Off
- Press Apply