As this thread seems to be devolving..... A couple of observations.

In American films involving stagecoaches, I noticed that the footbrake was on the right, so the driver obviously sat there, and the coaches would pass RHSide to RHSide. As the British do.
This may, of course, be arranged so that the right-handed guard could turn to shoot pursuing baddies without blowing the driver's head off.

The metric system was introduced, forcibly, by Napoleon. This joker wanted standardisation throughout his empire. After his time, the people he forced it on didn't go back to their old systems. Except as regards where Longitude is measured from and the calendar, both of which he changed in most of Europe.
(Anyone have any more examples of Napoleonic standardisation that didn't catch on?)