For now. Once enough EVs are on the road, it'll go back to being 2+ or 3+.
You can drive anything in that lane with a passenger. Just sayin.
IIRC, here in sand-land (AZ) you can drive solo in our OHV lanes with a vehicle that has less than four wheels (mainly motorcycles - but if you have the cash for one of those nice 3-wheeled "cars", you're still good).