Imo trains should be handcar, horse railcar, and the top should be a peter cooper locomotive (aka tom thumb). And for the rails, you could have wooden wagonways or metal plateways, with metal allowing higher speeds and efficiency with less maintenance at the cost of using metal instead of wood. (So you'd use wagonways for temporary mines and plateways to things you want to go between)
I think that is a realistic goal.
(Though if we want to be accurate, a pair of 5x5x0.5cm L rails is 1m3 of steel per km, so a bit too expensive, though I guess you could realistically have ones inside an industrial building.)
Of course if we have non insane ways of getting literally metric tons of iron (e.g. if we get an iron sand biome that you can easily-ish refine into iron semi automatically post steel) (currently you'd do like 500m of rail on a full iron vein.)
Also from an historical perspective, wagons on rails are actually pretty old, like we have records of carved stone wagonways in 600BCE, and wooden ones in the 1500s, though they were probably in use before, as it's just putting logs of the same size end to end and carving wheels to fit on the logs.
