IMO, this game is a mixture of cities in motion and Open TTD. Unlike railroad tycoon, each passenger counts as have his or her destination. This is what you have to do
Build a network within the city to various destionations. If you want to connect 2 cities via rail you will first have to make a network in your city to bring the passengers from various destinations to and from the railway station.
This game is not comparable to railroad tycoon 3 and sid meir railroads, infact it has a unique gameplay never introduced in the previous genres.
The game is incomplete as well but the devs are working on it (the game is better now than its initial release, thanks to the devs for releasing 3 patches uptil now). As you mentioned, road over rails, the devs have said that they will consider this feature.
@ifurkend!, i dont think so that the devs will leave the game in this stage so early as they simply can afford to do so. This is their first project. Their continuous support have led to players being positive and build a trust upon them.