On the Dash:
- Waymo vehicles crashed 68% less often than human drivers over 50 million miles studied
- Single-vehicle crashes dropped 85% and injury crashes dropped 81% compared with human drivers
- IIHS says current crash-reporting rules can’t yet support monitoring driverless vehicles at scale
A new study from the Insurance Institute for Highway Safety (IIHS) found that Waymo‘s driverless vehicles crashed 68% less often than human drivers. The study is the most comprehensive comparison of autonomous and human driving safety to date.
The IIHS analyzed 50 million miles of Waymo operation from 2021 to 2024. That’s the same period when the company expanded its ride-share fleet from Phoenix into San Francisco, Los Angeles and Austin, Texas. Researchers compared that data against 222 billion miles logged by human drivers over the same span.
Single-vehicle crashes came in 85% lower for Waymo vehicles than for human drivers, and injury crashes were 81% lower. The overall 68% gap was driven mostly by multi-vehicle crashes, which are harder to assign fault for and more likely to involve another driver’s error.
“The results show that, on a limited scale, these driverless cars are safer than human drivers, who can be impaired or drowsy or suffer lapses in attention,” IIHS President David Harkey said in a statement. “However, the present data collection system isn’t good enough to allow continuous monitoring of a large-scale expansion.”
To build the comparison, IIHS researchers removed crashes that occurred while a human safety operator was present in the vehicle, then reviewed the remaining incidents to determine which would have met the threshold for police reporting had a human been driving.
Researchers noted that driverless companies are required to report nearly every incident, including minor curb strikes, while human drivers routinely underreport. The IIHS estimates that half of all property-damage crashes and a third of injury crashes involving human drivers go unreported.
The findings come as Waymo continues rolling into new metro markets despite a string of recent recalls and federal scrutiny over specific incidents. The IIHS data gives the company and the broader AV industry an independent benchmark to point to as regulators weigh how to standardize crash reporting across driverless and human-driven fleets.
