I’ve heard this before.
If I remember correctly, this traces all the way back to the width of a Roman chariot.
And, it has something to do with the space required for 2 horses standing side by side with harnesses.
If you google “Pompeii roads stepping stones”, you will find pictures of the grooves made by chariots. Also, stepping stones were made in the road so that people wearing sandles could cross the street without having to step into sewage. I don’t remember the guage that our guide said it was.
How soon we forget the width of an oxen team and the bow length compared to a wagon width when we build our oxen yokes, which was later converted to rail and steam engine pulling the same wagons.
If we recall the last time we hitched up our oxen team to plow an acre of land to grow the food we consume, it becomes intuitively obvious that the bow length shouldn’t exceed 72 inches, and is more controllable at about 50”-70”.
Assuming most of us aren’t wealthy enough after Obamacare to own 2 large oxen to justify a 70” wide yoke, and measuring a common ox neck at his withers, say about 7.5-12” wide, say 9” and separating the oxen by 4x their bow each is about 36” plus 18” (2x bow) and remembering to keep about 1-1/2” thickness separation between the bow and the oxen’s neck for his gait, we have a natural pull width of about 36” + 18” + 3” = 57” minus width of a steel wheel and bolt linkages about 56.5” or 4’-8.5” for the width of our wheeled cart so as not to impede the gait of the oxen team.
Using this width as our gauge, we conveniently are able to use our carts and wagons either using our newly acquired ObamaOxen or Obama’s penchant for train transportation.
See how much better off we will be in 4 years than we are now! /s