To keep it short I agree with you …. and here is why ….
Yes you don’t need a planning tool. What you need is simple, just like in the game Banished that was released rather recently.
In that game you can build without actually building. You just plop down whatever you want to build and put it on pause. In Banished they actually build stuff so “pausing” works. In this game it is built instantly and money taken from you instantly. So you just need a mode where you can build and build and test and tear down and rebuild without loosing any money.
You should even be able to create lines on this future tracks.
And when you are ready one should be able in the line tool window to be able to say “build/realize” what is necessary for the line to function. And then the game builds the track you have planned but only that.
If the game implemented that then there is no need to sit and await you have the money necessary for your next project. Now I have to sit and make plans on paper because planning is very important in this game where you spend hours constructing just to realize “dang!” I forgot about that iron ore mine, now it is on the wrong side of the tracks.
I agree with you we should be able to build without paying money just to see if it will work.
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About me planing. A paper, put down back blobs where the cities are. and draw the rivers roughly dont have to be exact.
Write down where all resources and factories are on the map.
Then draw line between Iron Ore —- Coal mine —- steel mill
and Forest —- saw mill
and Oil —- refinery
And then you take a good look at this and start drawing the lines and try navigate this maze of transport needs, passengers and a mix of goods so that you get each thing on the right side of the track. This result in no optimum straight lines but a railroad that snakes around all these obstacles trying to cut a path on the right side of each and giving space for switching trains so they can change track as necessary.
It looks rather nice compared to the absolute optimal route. If you keep doing that you probably will have to start and build a lot of railroad tunnels or bridges and you get a spaghetti web instead of a railroad system that looks like the blood veins in a body.