Games are limited compared to real life. For example, this one can't just do arbitrary curvature radii (ie, let the player pick their own) for 2 reasons:
- Each curvature radius would require a set of entities to be made.
- The game can only allow a maximum of 3 path choices from any one junction (left, straight, & right), otherwise this causes problems with manual driving navigation.
As such, the devs had to pick a radius that felt balanced to them. What we have now is what they happened to pick.
Also, whenever I see people post pics like that and say "look how close they are in real life", I don't think they understand just how much distance is really between those railways.
Here in the US, rails are typically "standard gauge" sized, meaning 1.435 meters between the inside edges of the rails. And according to
this, in the state of Pennsylvania at least, the minimum allowed distance between the center point of parallel railways is 4.115 meters
Clearances between Parallel Tracks
- The minimum distance between the center lines of parallel tracks shall not be less than 13 feet, six inches, (13'6") for main tracks and not less than thirteen feet, six inches, (13'6") for yard and side tracks.
(13'6" is approx 4.115 m)
This means there's approximately 2.68 meters between the outside rails of each railway, or 2.68 tiles of in game space.
Now yes, because of the curvature radius the devs picked, we're actually at 4+ (technically 5, I think, as I think I measured in game rails as having an approx 1 m gauge at one point), but again, game restrictions, and as has been mentioned, this will be solved for 2.0 to where you can have them right up against each other.