I heard this a few years ago, and going through old notes, decided to post, from the CBC series: As It Happens
To listen: Real Audio file, go to minute 21m:20s
The introductory text: "For as long as most of us can remember, the citizens of North America have been firmly entrenched on the right. Now, a bold and shocking proposal in the state of Ohio may result in a wild shift to the left. And it will come as no surprise that the French are involved.
The Ohio Department of Transportation is currently mulling over an unprecedented traffic diversion. If a recent recommendation comes to fruition, drivers on U.S. Highway 224 may find themselves driving -- if only briefly -- on the left side of the road. The lane-reversal plan is a proposed import from the city of Versailles, France, where Gallic drivers have found it to be "la rue juste"."
This is a clever idea to avoid left-turn conflicts (or at least put them where you want them and make the crossovers seem like through movements. Wikipedia has an article.
My former classmate, Joe Bared, now at FHWA did a study with colleagues:
TechBrief: Drivers' Evaluation of the Diverging Diamond Interchange, FHWA-HRT-07-048
The Hwy 224 proposal in Ohio was rejected. The proposal for Kansas City seems alive.