I agree with sheriffcubic that there should be a central station where the trains terminate at along with cars you can drive in first person as yourself the player, and a bus station at each stop, luggage cars and racks on the platform in which station porters ( ai's or ingame players ), a timetable which you can change the route your heading to, a ticket booth which you can change the price of the tickets for each trip. maybe include different jobs you can apply as such as: station porter where you carry luggage bags to the carriages on carts in first person 3d, a train conductor where you have a whistle icon to signal passengers to board. a dispatcher or signalman in the platform with a flag in one hand. maybe also include more international trains from different countries to give diversity to the game. like the maglev bullet engine from japan,or american passenger trains things like that adds so much to the game and yes it may create lag and make the game more laggy for low performing devices but I think its worth it in the long run.
Maybe try https://epicport.com/en/ttd# and build your own Maglev network. From experience though, they cost alot of in-game money, up to $222,000 and increases because inflation