I don't think either solution is going to be the eventual winner. I expect the eventual rollout of 5G+ to be the game changer.

Much like how a pilot captain boards a ship to steer it into port, traffic systems will be able to be a bit more 'hands on' when it comes to getting traffic through junctions safely, regardless of the weather. Hence, on the final journey through a city, the city traffic systems will be directing your car.

For the journey on highways between built up areas, variants of today's self driving systems will suffice.