I think they should be accepted on a Federal level. USDOT...ALL states.
Why wouldn't you? The way gas prices are now, it would be in our best intrest to embrace smaller, more efficient vehicles. If fuel demand goes down, price will follow. Everyone driving Peterbuilts to work is why the prices are so high now.
The size should be a non-issue as well. Look at a VW Beetle, Mini, Honda Fit, Toyota Yaris, Chevy Aveo, Hyundai Accent, etc etc.....all about the same size as a KEI.
RPM: Good luck and thank you for doing your part. <S>
I think those little trucks are cool. They are about the same size as my '73 Toyota HiLux truck. Easy to drive easy to park . Great on gas.