http://trafficwaves.org/trafexp.html
tl;dr driving smoothly and leaving traffic gaps ahead can prevent traffic jams or slowdowns
Having just a small percentage of automated cars with traffic optimizing behavior may actually increase road capacity.
An other traffic optimization (which doubles down as a gas optimization) is "car trains": cars following one another very closely (much more closely than human drivers would handle)
You could hardly be any less correct. This is by far the most major and interesting feature enabled by auto-driven and cooperative cars: http://www.sartre-project.eu/en/Sidor/default.aspx
> as it's still really dangerous.
Not really.
Cooperation would already go a long way to solving congestion with just local cooperation though:
* higher road density (cars can pretty literally travel bumper-to-bumper)
* better handling of congestion (car train can smooth local slowdowns over all its component cars)
* much, much improved merging and splitting of roads (including local flow analysis e.g. a small road merging into a bigger interstate with a 3:1 traffic ratio could be managed into a "perfect" 3:1 merge frequency)
* simplified urban planning (if only cooperative automated cars are on the road, you can get rid of red lights)