With software, there is no such powerful peer contract. Software is not yet as good at self-healing (e.g. braking suddenly) if something unexpected happens. How do you handle a system exception safely and robustly at 65mph?
Automated cars are a pipe dream. Automated auto-pilot for cars on highways (e.g. automated platoons of cars moving in lock-step until they reach their exit) a.k.a Intelligent Transportation Systems (ITS) will be persistently hobbled in adoption because failure of the interface between humans and machines is dangerous at highway speeds. Recent ITS research has focused on trying to academically prove MITM attacks cannot work for certain ITS systems. Also, most people like freedom to drive whenever, whereever they want.