As was emphatically explained to me, they're considered to be just like normal headlights. You don't use them all the time, but they must work when the mechanic turns them on. It may not be the same in all states with inspections, and the law may have changed since then, but it is something to consider if you get foglights because they look cool or are included in the package you purchase.
Technically it's the same here in the UK. Any auxiliary lights fitted must work as well, such as extra spotlights, driving lights etc. E.g. pre-1981 cars didn't have to have rear fog lights and motor shops sold them as bolt on accessories, but if you fitted them they had to work for the MOT and have a visible indicator light inside the car when they were on.
Your right, but I wish someone would give me £1 for every car I see at night with just one headlamp/tail light showing. I'd soon be very wealthy.....
There were a few comments initially - but most Gen4 owners would be using their original tyres still. @soldierguy replaced his and commented. There are other comments in PriusChat re the better efficiency of 15" vs better grip of 17" tyres.
Here in Finland. If you have fog lights they have to work in inspection (and even water condensation inside the lamp can cause a fail, even if the lamp works) Annual inspections but 1st inspection 3 years after purchase 2nd inspection after 5 years and after that annually
I've lived in the town of Nokia for 10 years from 1980 to 1990. Had many friends working summer jobs at the Nokian Tyres factory there and I still know at least one engineer who works for Nokian there (we used to play in the same basketball team as kids). I've had one set of Michelin X-ice studded tires in one car I think. Other than that I've driven my whole life with studded Nokian winter tyres. So they are the only ones I know. The best when it's ice or snow by far.