Hello I started working on a modern fictional version of Oberallertalbahn (Celle - Gifhorn Stadt). Watch my first (german) diary video on YouTube here:
Good luck, I'm looking forward to seeing more from your project! I also feel that the scenery is the difficult bit, especially areas with many buildings and a lot of stuff happening close to the tracks. I chose a completely different approach (I try to do track/signals and scenery as I go) and I have around 1.1 km that I'm sort of happy with now scenery wise Maybe if you create that cabride video you could try to explain in voiceover what would be seen at the moment or maybe sprinkle in some of your reference photos, that would make it probably a lot more entertaining.
Nice video, even though it is semi-fictional I am very exited for this project. If you need help contact me, I currently work on a timetable and want( not sure if I ever will) to learn blender.