> 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.