By the time we get to fully integrated and automatic cars, the infrastructure will be changed to accommodate. There's lots of ways to keep cars in lanes without relying on cameras. As for the ability to manage limited traction, well, it's not like people are masters of that skill either...
There won't be a sudden flip from all human to all robotic. Best guess is it'll start in cities with dedicated lanes, not dissimilar to HOV lanes, for appropriately equipped vehicles, where you drive yourself to the merge point, and it takes over from there. There will still be roads for 'dumb' cars, but as things progress, it'll go from one lane for the self-driving cars to one lane for the human operated ones.
I don't think any of this eliminates human-operated vehicles for the foreseeable future. In a country like Canada, it would be a very long-term project just to develop the infrastructure. But adding it on the small percentage of roads that carry 99% of the traffic on a day-to-day basis would be much more manageable.
But eliminating the human factor from commutes and rush hour traffic is by far the best way to speed those things up. From tailgating, riding brakes, slowing for things roadside, changing lanes, merging, cutting each other off, getting distracted, falling asleep, road rage, plugging the passing lane, and on and on, the causes of traffic slow downs are from the human factor, not volume. Eliminating the stupid and the selfish from the equation would make the biggest difference to traffic flow...