Well, see it like that:
Somewhere in the CSA, a US army convoy is stopped on a road by a single man standing on its path, a confederate sheriff from the look. The sheriff's car is parked on the side of the road... on the wrong side. Something is off.
The American soldiers are very nervous, everyone has a rifle or a pistol ready to fire; all those ambushes...
Then, an American officer and his escort step out of the armored car leading the convoy.
- What are you doing?! Get off my road !!
- I'm sorry sir, I don't mean no disrespect to an officer of the United States army like you. It's just, you see, we have a new law that requires driving on the left side of the road. You understand, we would not want accidents to happen with all these people driving left now, would you?
- Wh... What? What law? When?
- The governor signed it this very morning, sir.
- Are you kidding ...
In the distance, cars are seen approaching on the same lane...
The railroads are under the US army regulations and jurisdiction for now, but what of the roads? If they have not been explicitly put under their jurisdiction, such a loophole could enable the Confederates to annoy these '
damned right-hand driving Yankees' at every turn.
That's silly, but I read an anecdot about the German occupation of northern France in the Great War, where it was required to take off your hat in respect when in presence of Germans... and people just stopped wearing hats.
Silly spiting so, taken to a whole new level.
May be part of a wider strategy of making American occupation every bit as embarassing, annoying and frustrating as can be, like the Germans did when France and Belgium occupied the Ruhr in 1923.
The Democrats don't have to be bothered opposing it.
But my point is more about the initial reaction from the public after. Precisely because it would be one of the most visible measures by the Root administration, it would be resented as technocratic overreach, even though metrication has been simmering for a couple decades now.
Said otherwise, if the metrication law was passed a few years later, during the 1920s, under the Democrats, noone would bother, and most people would say it makes great sense, it's a natural evolution. But make it pass under Root, and the same people would say, perhaps Roosevelt papers would title it like : "
what's he doing bothering us with his meters, that damn Liberal technocratic snob?!!".