In our current transportation ecosystem, operating a motor vehicle and sharing the roadways with other road users entails a certain amount of risk. The legal system helps to manage this risk by placing a duty of care on each road user, including drivers, bicyclists, pedestrians, etc. and clarifying the expected behavior for tasks such as following, changing lanes, or navigating intersections in specific provisions of the traffic code. Through continual refinement over time, the traffic code and the broader legal system that surrounds it reflect the balance between safety and mobility that society demands.

Developers of automated vehicles must interpret this legal system when designing algorithms that make decisions for any scenario which the vehicle may encounter in its Operational Design Domain. This translation from legal precedent to algorithm is far from trivial. Even straightforward legal structures can be challenging to rigorously code into an algorithm and traffic laws involve a number of subjective concepts related to reasonableness and the extent of the duty of care. For example, the Uniform Vehicle Code’s requirement of a “reasonable and prudent” following distance must be translated into a numerical value that the automated vehicle can regulate. Furthermore, such translation must apply to exceptional cases when the duty of care owed to each road user and the provisions of the traffic code cannot be satisfied simultaneously. Developers must handle such cases in a manner that is legally defensible, ethically sound with regards to its treatment of human harm and technically implementable.

And so it goes…