  This study compares the safety of autonomous- and human drivers. It finds
that the Waymo One autonomous service is significantly safer towards other road
users than human drivers are, as measured via collision causation. The result
is determined by comparing Waymo's third party liability insurance claims data
with mileage- and zip-code-calibrated Swiss Re (human driver) private passenger
vehicle baselines. A liability claim is a request for compensation when someone
is responsible for damage to property or injury to another person, typically
following a collision. Liability claims reporting and their development is
designed using insurance industry best practices to assess crash causation
contribution and predict future crash contributions. In over 3.8 million miles
driven without a human being behind the steering wheel in rider-only (RO) mode,
the Waymo Driver incurred zero bodily injury claims in comparison with the
human driver baseline of 1.11 claims per million miles (cpmm). The Waymo Driver
also significantly reduced property damage claims to 0.78 cpmm in comparison
with the human driver baseline of 3.26 cpmm. Similarly, in a more statistically
robust dataset of over 35 million miles during autonomous testing operations
(TO), the Waymo Driver, together with a human autonomous specialist behind the
steering wheel monitoring the automation, also significantly reduced both
bodily injury and property damage cpmm compared to the human driver baselines.
