Give Railroad Empire a try, maybe you'll like it.
The UI is very smooth, it's got the best and friendliest track-building I ever saw in a railroad game, laying tracks, tunnels, bridges, stations, supply towers, signals is just a breeze. Creating trains and routes is also very sleek.
What ended up killing it for me is the lack of long-term gameplay. The game, even in free mode, is far too fast-paced (for my taste), plus you cannot progress through the various eras, you choose a starting era and you're stuck with it to the end of the game. The economy/management side is also poor... After you have a couple of routes the money just starts pouring in and it becomes just a free building game, invalidating / rendering completely pointless all the supply/demand, train crews, special wagon types, stock market, etc mechanics.
There is a tech tree, but it's mostly just for show, techs don't make much sense and they 're just ways to give arbitrary buffs that barely have anything to do with the tech itself.