Only 7500 kei vehicles are imported into the entire US each year - is this really a problem that needs addressing?
https://amp.cnn.com/cnn/2024/07/14/business/kei-trucks-japan...
Being visible as a pedestrian or biker is a lot easier with kei cars parked on the street than some of the F150s I have to deal with now. Many of Boston’s streets are also notoriously tight compared to other sections of the country.
If there was wider movement kei cars (which is a big assumption - I can’t imagine many people would be willing to tolerate right side driving) there would be more road injuries of the drivers, probably, but that would also be weighed against injuries to non drivers.
And I don’t have an opinion either way, but it seems reasonable for the appropriate government agency to, even if the issue is currently pretty limited
Edit: although the noise thing is valid, I'm perpetually annoyed with the "loud pipes save lives" crowd, that's obnoxious.
https://gearjunkie.com/motors/motorcycle-vs-vehicle-emission...
See this article to show how a modern motorcycle would be ~100x less polluting than the example vehicle given in the article referenced:
https://www.acem.eu/new-euro-5-environmental-standard-for-mo...
But the moment it belongs to you and even before you leave the lot, you can have illegal aftermarket exhaust systems installed that not one governing body in the United States, nor most of the rest of the world, will come close to enforcing any noise or emissions laws against.