US roads are built for much, much higher speeds. Kei cars purposefully give up safety with the caveat that they’re only used on low speed roadways, and Japan designs their roads with the intention of these vehicles being acceptably safe in that context.
On intercity highways in Japan you are driving next to as large trucks as anywhere I've driven.
Ex. There is no visible difference between Germanies highways (no speed limit) and Switzerland with 120kmh max
IIUC a typical "real" Japanese kei truck can manage 60-70 mph easily, if not comfortably. That's more than enough to hang with traffic on the vast majority of American roads, and nobody sane is using these things as long distance transportation. So the "they're too slow" argument is clearly bunk.
That leaves the crash safety angle. I can't help noticing that motorcycles are still legal, or did I miss something? Anyway, it's very emblematic of the American approach to road safety that some small, light vehicles are uncertifiable on safety grounds, but the sizes and weights of personal vehicles are allowed to grow in unbounded fashion. There is clearly no safety issue with getting groceries and picking your kid up from school in something that weighs most of 10K lbs and has such dogshit sight lines that you could run over a whole school bus's worth of kids in a crosswalk and hardly notice.
Freedom? Personal responsibility? Not quite---you can make a choice to endanger other road users, but never yourself! Unless you ride a motorcycle, in which case that's okay.
Perhaps an attempt to balance both.
Working class buys cheapest available <insert product here>. Allow sale of new vehicles without seatbelts, airbags, etc. and that becomes the attractive thing to lease (assuming it can be insured). Allow, say… uninspected beef & dairy products instead and if those savings are passed on, that’ll be purchased by low-income folks too.
Motorcycles have a built-in discouragement from the cost-optimizing behavior: lack of those two extra wheels.
>Not quite---you can make a choice to endanger other road users, but never yourself!
Would be open to ways regulate enormous vehicles which’re dangerous to the public outside their cabins. Keep taxpayers alive + out of hospitals they might not be able to afford (cost passed on to me).
But, (again) since you mentioned it---"new vehicles without seatbelts, airbags, etc." is a misrepresentation of modern kei vehicles. Kei cars sold new today have seatbelts, crumple zones, airbags, ABS, AEB, and so on. They perform well in crashes for their size---sure, they are small cars, but they aren't a scheme to foist unsafe-by-design shitboxes on people who can't afford something safer.
More recent kei pickups still use the cabover design which necessarily limits your available crumple volume, but even those have the modern safety systems. The imports you see in the US are 25+ years old, which affects their safety outcomes in the way you would expect. People here buy them despite the age and import rigamarole (arguably a terrible value on paper) because there is demand.
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The Smart Fortwo is probably the closest thing to a modern kei car we've had in the US outside of imports. IIUC they made it work with our regs by designing to them from the start, but in practice its safety outcomes were apparently pretty similar to kei cars in Japan, and exactly what you'd expect: decent performance in single vehicle crashes, but they suffer in crashes with larger vehicles. They weren't sold on the cheap to lure cost-conscious buyers (neither are kei cars in Japan), and ultimately I guess Americans just didn't want to buy them. But they were solid runabouts for city dwellers and didn't feel unsafe to drive in that context.
tl;dr: If there was some viable scheme to sell new-ish kei vehicles in the US, I would not be terribly worried about the scenario you describe, and IMO implying some equivalence between e.g. a hypothetical moderate regulatory carve-out for such vehicles with abandonment of beef and dairy product inspections is utterly ridiculous.