Assuming the cars are designed to practice basic defensive driving (especially keeping a safe distance), I don't really see a realistic scenario where this could happen.
Far more likely is a human driver screwing things up.
One issue with keeping a safe distance is that doing so means you travel slower than nearly everyone around you on the highway, since the space you leave in front of you is viewed as an invitation to merge ahead of you, meaning you have to slow a bit to open to a safe distance again, which prompts someone else to jump into the "empty" space...
However, I suppose a safe distance for an autocar should be considerably smaller than for a human-driven car, since the start of braking would be essentially instantaneous.
However, I suppose a safe distance for an autocar should be considerably smaller than for a human-driven car, since the start of braking would be essentially instantaneous.