"I wish my car had a drone for instant scouting of traffic-jam alternates."
No, you wish your car could listen in on the currently aloft drone to get traffic updates.
Having your own drone would cause a drone traffic jam overhead, with all the other well-provisioned drivers releasing their own drones. Auto-avoidance? yeah, that's working pretty well on the road, hence the lack of need for these drones at all.
You just want more than Google Maps and Waze does now. Good luck with that.