Originally posted by tim60 Just like the standard train gauge for tracks is based on the distance between wheels on Roman carts, which were all the same because that dealt with the problem of the ruts worn in the road by everyone else.
Sort of correct, at least for standard 4'8.5" gauge tracks (there have been more than a hundred different gauges in use around the world). It's probably more correct to say that both horse-drawn carts, including Roman ones, and Stephenson's railway got their width from what fit being pulled by two horses abreast. Stephenson's choice was probably more by old habit than anything else. Had Brunel "won" the standard would have been 7' and a bit. It would have made railroad tracks more expensive to build, though.
(This is not an attempt at usurping Bert's place on the throne of besserwisserness.)