I noticed there are different kind of players. I don't really explore the routes, I mainly drive them. Coming out of the cockpit is not that nescecary for me. I watched a video from Picelade where he describes how he loves to jump in to trains over and take over. I also read about not enough AI on some routes, mostly this comes down to performance. What if you separated free roam from the journeys. Make the journeys all about driving the trains, no free roam available but more AI traffic as not every AI train has to be fully functional? Keep free roam it is today so you still have the same gameplay but you will better journeys with more realistic looking traffic.
Journey services are just timetabled services so don't understand your comment on more ai trains in journeys when it's the exact same thing. Also, just don't leave the cab then if you don't want free roam. Tsw is not tsc anymore. Walking around is a core feature of tsw and it's not going to get removed from journey mode just cuz you don't want to walk around. There are people who want to walk around and explore the station. You have a choice to stay in your seat
Well if you take the "timetabled service" and remove the ability to free roam there is a lot of stuff that can be removed. AI trains don't need full interior for example. You can remove a lot out of the route which frees up memory. More memory that can be filled up with lot's of AI trains.
