What would an unmanned vehicle do if I tried to force it off the road?

I was reading that Kroger is beginning to deliver groceries now link using unmanned, autonomous vehicles.

Suppose I were not a nice person. I wanted to cause it to veer off the road, cutting it off and deliberately forcing it out of the traffic lane.

What are these autonomous vehicles trained to do? Would they docilely just go off the side? Would they ‘fight back’ and try to retain their position? Would they simply stop in the middle of the street?