It could be a moving target. Maybe you could start with a generic test, for instance: x miles in random location with random conditions. After that you could

It could be a moving target. Maybe you could start with a generic test, for instance: x miles in random location with random conditions. After that you could add tests when a problem appear. For instance, you could add the conditions where that woman was killed the other day. When another accident happens you would add a test appropriated to that conditions. Regression testing for driving.