NavList:

Contrary to your post, there are five standard railroad guages used in Europe, four of which are incompatible with the U.S. Standard guage.

https://jakubmarian.com/track-gauge-by-country-in-europe/

There are four main track gauges used in Europe. The so-called standard gauge (1,435 mm), the 5 ft gauge (1524 mm, later redefined as 1520 mm in the countries of the Soviet Union, which is generally compatible with trains built for the 1524 gauge), the 5 foot 3 inch gauge (1600 mm) used in Ireland and Northern Ireland, and the Iberian Gauge (1,668 mm) used on the Iberian Peninsula. The map below shows how these gauges are used in“Track gauge” is the perpendicular distance between the inner faces of the two rails of a railway. Just like with many other things, it would have been better to have a single standardized gauge everywhere, but, for historical reasons, different countries use different gauges.

My point is that even France, the purists of the metric system, have adopted compromises of that system when it makes sense such as speedometers and tachometers calibrated in non-metric units in cars that I have rented there,  No country is purely metric. I like the metric system and use it all the time but the U.S. should only make changes when it makes sense, not out of some fervor for puritanical metrification, When U.S. products are intended for overseas markets it makes sense for American manufacturers to use the metric system and metric specifications for technology and parts. For products destined for the U.S. market ( which is the world's largest market) it makes sense to stick to the standard system.

gl

There are four main track gauges used in Europe. The so-called standard gauge (1,435 mm), the 5 ft gauge (1524 mm, later redefined as 1520 mm in the countries of the Soviet Union, which is generally compatible with trains built for the 1524 gauge), the 5 foot 3 inch gauge (1600 mm) used in Ireland and Northern Ireland, and the Iberian Gauge (1,668 mm) used on the Iberian Peninsula. The map below shows how these gauges are used in

“Track gauge” is the perpendicular distance between the inner faces of the two rails of a railway. Just like with many other things, it would have been better to have a single standardized gauge everywhere, but, for historical reasons, different countries use different gauges.

There are four main track gauges used in Europe. The so-called standard gauge (1,435 mm), the 5 ft gauge (1524 mm, later redefined as 1520 mm in the countries of the Soviet Union, which is generally compatible with trains built for the 1524 gauge), the 5 foot 3 inch gauge (1600 mm) used in Ireland and Northern Ireland, and the Iberian Gauge (1,668 mm) used on the Iberian Peninsula. The map below shows how these gauges are used in

There are four main track gauges used in Europe. The so-called standard gauge (1,435 mm), the 5 ft gauge (1524 mm, later redefined as 1520 mm in the countries of the Soviet Union, which is generally compatible with trains built for the 1524 gauge), the 5 foot 3 inch gauge (1600 mm) used in Ireland and Northern Ireland, and the Iberian Gauge (1,668 mm) used on the Iberian Peninsula. The map below shows how these gauges are used in“Track gauge” is the perpendicular distance between the inner faces of the two rails of a railway. Just like with many other things, it would have been better to have a single standardized gauge everywhere, but, for historical reasons, different countries use different gauges.