There are no 'accidents' even now. The measurable effects of all collisions are caused by physics, the powerful combination of speed and mass which are products of intentional, premeditated, heavily marketed vehicle design. This will remain true even as vehicles approach level 5 autonomy. So will the competitive nature of our transportation market.
Level 5 will never be attained, less for technical difficulties than for human reasons. I refer to the principles of liability, related to system design, and various human behaviors, both of vehicle occupants and interaction with those choosing to use a public right of way by other means. The corporate profit motive will demand ever higher degrees of segregation and conformity, the slow erosion of our machine-free rights to public space.
But there will be heavily promoted illusions.