I’m not sure what you are asking, but if it’s asking how much electrifying a railway would cost, it depends on what you are doing.
The cost to electrify an existing railway is only around 1-5 million dollars a mile depending on locality. Which is cheaper than building a two lane undivided road ( 3-4 million per mile), and vastly cheaper than expanding an existing highway (10 million per lane per mile).
Again, this only seems expensive or materially difficult if you don’t know anything about mass transit.