There is no real competition despite having similar facets. A road has an aesthetic quality that a rail would not. A rail will go faster though. A road can help keep you spatially oriented whereas railways can get a bit divorced from surroundings with samey tunnels. Both offer a link and are flat, but I feel there is enough merit for them to be able to coexist. One is a quick way to get around, and the other offers old and new players an easy way to figure out where the various areas are. I plan to eventually link to not just houses, but any major projects worth visiting. A rail system would have trouble with that I think, unless it got monstrously complex. It is good for hitting major spots though.
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There is no shame in not knowing; the shame lies in not finding out