To successfully develop self-driving cars, without spending NASA moon mission like time and money, we need to put a value on a human life. Maybe even different values for passenger, driver, pedestrian, other motorists, policemen, etc. Then the risk, time, and money to spend will be easily defined. If some task will take a software engineer (paid $150k/year) half year to develop but only increase safety enough to save 1 pedestrian per decade, and a pedestrian is valued at $50k, then maybe the dev can work on something else. Numbers are made up just to illustrate the point. But this is how Tesla, or any other self-driving car-maker can quickly bring self-driving tech to the public in a cost-effective manner, and within reasonable time-frames.