I really don’t see why ppl think 16×16 Km is small. There is no game with such huge map, except perhaps OpenTTD that have much smaller scale and no people walking around, then of course you can have huge maps, as things in the game also look much smaller and zoom in is limited.
RRT2 have much smaller map. Also in RRT2 an entire city is represented by a bunch of houses. In Train Fever you can see people walking around, so of course the map will be able to hold less. But RRt2 do not offer transport inside the city.
Its a matter of understanding the limitations. And its not limitations of engine or computer specs, its logical limitations. Just like ppl complaining that in CiM 2 a bus takes 4 hours to go around the block. Well when you have vehicles running in real time speed and time running 1 minute every 8 seconds, what would you expect? Magic?