If current Waymo counts as level 4 then we need sub-levels for them to have much meaning. They are a long way from supporting something like autonomous driving

If current Waymo counts as level 4 then we need sub-levels for them to have much meaning. They are a long way from supporting something like autonomous driving geofenced to all major US cities in all weather conditions. That big step up is still far behind true level 5, which can handle poorly maintained roads and all of the other weirdness one can encounter outside of major first world cities.