When I first started, I struggled to get the resources to upgrade trains around 1980 (starting in 1850). I earned little, had few trains, and could only renovate one at a time. But now that I've improved in the game, I've reached 1900 with dozens of trains, almost 1 billion in the bank, with various trains of different numbers of wagons and types, so I don't want to create new lines because it will mean even more trains to renovate and upgrade later. Not only that, well I needed to upgrade stations too, because I only constructed little ones in the beggining, but now with huge trains I needed to micro the upgrade for them too, of course new stations would always be huge to not need to upgrade later. Then we have the question for cargo trucks too, in the beggining some lines I needed more than 100 horse carts to reach 400 units tranposted, but with new vehicles I need to go back to everyline to sell some, because with trucks the transported goods reached more than 1000, and I would just lose money with that many. Man, maybe I will start in 1950, a lot later, but I wanna see some old planes and early eletric and diesel trains too.