I think that if you were reading my comment charitably you could infer that I meant "under all conditions where a car is legally allowed to operate." I don't think you actually believed that I was saying that a truck should have the capability to drive on the road when a roadway is not legal to drive on.

You are seeing a fight that isn't there.

There is precedent for either roads or vehicles for choosing not to handle some conditions. In a driving rain storm you will find rest areas stuffed full of trucks and cars that picked that time to nap. In San Francisco Waymo first served some hours and not others, some areas and not others - some of these choices apparently related to fog and wet pavement. In Oregon, you will find roads open, but white-out-ed. Etc, etc. Nobody forces human vehicles to keep moving and most of the ones with some sense make choices. Which are available also to automated vehicles. - Sure it should be expected of the vehicle to find a safer place to move itself than right in the middle of the lane, like I point out in another response here.

> Truck or cars are not strictly required to operate in all conditions in the current system: roads, entire freeways close when the conditions demand. Or demand that vehicles stop and put on chains. There is precedent.

I think you're confusing things. Weather changes midway anyone's drive, and all drivers are required to drive safely and reliably even during sudden extreme meteorological events.

For a road to be closed, it takes an administrative action that reflects a decision that's largely arbitrary. Until a third party makes that decision, any driver is required to drive safely and reliability, regardless of the weather.