How safe is safe enough?

Teenagers have to pass a driving test before they can get a license.

• For autonomous vehicles, the standard of achievement is when it's better than a human driver.

Why it matters: Absent federal regulations on autonomy, AV companies are essentially self-regulated. They get to decide when "safe" is "safe enough," which is hard to prove and naturally leaves room for interpretation.

• "Just trust us" isn't very convincing to the majority of Americans who are afraid of self-driving technology, according to a AAA survey.

Driving the news: Aurora says it won't launch its driverless trucks until its safety case is fully closed.

• A safety case is a structured argument of claims, with supporting evidence, that companies use to show how and why an autonomous vehicle is safe enough to deploy on public roads.
• Each company's safety case is unique, based on the specific vehicle and where and how it would operate.
• In the case of Aurora, the safety case for launching driverless operations from Dallas to Houston was 99% complete as of the end of January, the company said recently.

Between the lines: Aurora's safety case framework is explained in its voluntary safety self-assessment that all AV companies are encouraged to file regularly with the National Highway Traffic Safety Administration.

• These voluntary filings are an effort to build public trust through transparency, but they can vary in depth and rigor; some read like marketing brochures.
• Gatik, an AV company focused on "middle-mile" logistics (such as between warehouses), enlisted a third-party auditor to validate its safety case in an effort to set a new benchmark for transparency, beyond self-certification.

The bottom line: Transparency and data could help build trust in autonomous vehicles, but given consumers' persistent fears about self-driving technology, it's going to take time.