

The long tail of global colonialism ;-) https://en.wikipedia.org/wiki/Left-_and_right-hand_traffic
Also, while not entirely accurate, an even older history, ahem, driving, the modern world http://www.astrodigital.org/space/stshorse.html
Without India I suspect Driving on the Left would be relegated to history books by simple economics.
Though with EVs a lot of the production costs of doing both could be eliminated.
except for the pollen. Nanopores / tiny holes seem like they’d get fouled up by dust and things pretty quickly.
really interesting idea, just wonder about the real world operating environment issues.