I agree that the ethical points here are worth considering. Questions of safety and human factors are critically important to how this technology is regulated and developed. There are also questions regarding how and where these vehicles should be able to operate, i.e. should these cars ever be allowed in dense, pedestrian areas. However, citizens get to decide the context and rules for how and where cars (robotic or otherwise operate); therefore, citizens can design a system that eliminates many of the troubling scenarios you have raised.
I don’t believe that autonomous cars will ever have a policy for how to value human life. It’s simply not how these systems work. What they can have a policy for is avoiding dangerous situations in the first place. None of your examples account for different road topology and safety rules. Vision Zero is one excellent example of how we can think differently.
Robots may not be good at moral decisions, but they are excellent at executing repeated, mundane task correctly and maneuvering far more quickly than humans can. No system will be perfect, but they can be designed to fail safe and mitigate risk of crashes and injuries. We should start building all cars and trucks to be drastically more safe with the path to autonomous ones being a secondary goal. Electronic stability control, automatic braking, adaptive cruise control, and lane keeping are examples of technologies that both improve safety and make driving more automated.
As the world stands today, human-operated vehicles cause far too many deaths, injuries, and economic damage. For too long, cities have been designed for cars and not people and this has resulted in deaths and a reduced quality of life in many cities. Cities can do better and in many cases are. Automated cars, buses, and trucks are a compelling facet of a transportation future where people move more quickly, conveniently, and safely. How autonomous and automated cars are developed, should be part of an overall conversation about how cities are designed and how a mix of transportation solutions will meet everyone’s needs.