Apparently, and perhaps not surprisingly, the US allows it on highways. Which helps explain why their traffic related deaths rate per capita is almost twice the European average.

I've never seen anyone do it so I'm pretty sure it's illegal in all countries were I've found myself on a highway. The US and Germany (due to their free speed generally quite weird autobahns) come to mind as countries that might allow it.

I drive a lot in the UK for work. I see it occasionally when younger and/or angry drivers get frustrated with overtaking lane hoggers. Sometimes I also see people do it very slowly and overtly for that same reason.

Generally, I don't think people want to do it and are aware of the dangers. But it's easy to do it without being caught, unless it goes wrong of course.

Downvotes from all the Americans who don't realise people drive on other sides.

The brits are experts at queueing

I'm turning left on a two-lane street, waiting for incoming traffic to clear, and some jackass pulls into the right-turn cutout to pass me. It's both rude and dangerous.