  This paper frames recent publications from Waymo within the broader context
of the safety readiness determination for an Automated Driving System (ADS).
Starting from a brief overview of safety performance outcomes reported by Waymo
(i.e., contact events experienced during fully autonomous operations), this
paper highlights the need for a diversified approach to safety determination
that complements the analysis of observed safety outcomes with other estimation
techniques. Our discussion highlights: the presentation of a "credibility
paradox" within the comparison between ADS crash data and human-derived
baselines; the recognition of continuous confidence growth through in-use
monitoring; and the need to supplement any aggregate statistical analysis with
appropriate event-level reasoning.
