Many European countries allow registering atvs for street use. CFMoto offers an electric locking REAR differential, in addition to front locking diff in these countries.

https://cfmotoparts.eu/2021-atv-cf1000atr-rear-axleon-cammand

I didn't want to put two vids in the message, so copy / paste this into youtube: How the differential works ( atv - cf moto 520 eur4)   

Here is some stunning scenery from Switzerland on a CFMoto Cforce 625. His road speed peaks at 80kph = 50mph:

https://www.youtube.com/watch?v=PVz-P1DKFGE