Is there not a model railway scale that will supply the right scale track?
The problem with that is model train tracks aren't usually in proportion to the train, ie. the tracks (and thus gauge of the model wheels) tend to be wider than they should be, to make it more stable.
My dad would be able to bore everyone into floods of tears on this subject, but there are lots of different gauges of railway throughout the world and historically it was even more varied. Unless you really want to research the correct gauge for the genre you're looking to model*, it might be an idea to just go with what looks nice to you.
*When I was looking to do WW1 Palestine and was looking for cheapo train sets for arabs to sabotage, my dad told me they use 1m narrow gauge, because the Turks mostly had old German rolling stock. That would be around 15mm wide tracks in 28mm scale - can you imagine how tiny that would look on the table?