Human Drivers Keep Rear-Ending Waymos

Waymo’s driverless cars have a much lower crash rate than human drivers, with fewer than one injury-causing crash per million miles driven, compared to an estimated 64 crashes by human drivers over the same distance. As Ars Technica’s Timothy B. Lee notes, a significant portion of Waymo’s most severe crashes involved human drivers rear-ending the Waymo vehicles. From the report: Twenty injuries might sound like a lot, but Waymo’s driverless cars have traveled more than 22 million miles. So driverless Waymo taxis have been involved in fewer than one injury-causing crash for every million miles of driving — a much better rate than a typical human driver. Last week Waymo released a new website to help the public put statistics like this in perspective. Waymo estimates that typical drivers in San Francisco and Phoenix — Waymo’s two biggest markets — would have caused 64 crashes over those 22 million miles. So Waymo vehicles get into injury-causing crashes less than one-third as often, per mile, as human-driven vehicles.

Waymo claims an even more dramatic improvement for crashes serious enough to trigger an airbag. Driverless Waymos have experienced just five crashes like that, and Waymo estimates that typical human drivers in Phoenix and San Francisco would have experienced 31 airbag crashes over 22 million miles. That implies driverless Waymos are one-sixth as likely as human drivers to experience this type of crash. The new data comes at a critical time for Waymo, which is rapidly scaling up its robotaxi service. A year ago, Waymo was providing 10,000 rides per week. Last month, Waymo announced it was providing 100,000 rides per week. We can expect more growth in the coming months.

So it really matters whether Waymo is making our roads safer or more dangerous. And all the evidence so far suggests that it’s making them safer. It’s not just the small number of crashes Waymo vehicles experience — it’s also the nature of those crashes. Out of the 23 most serious Waymo crashes, 16 involved a human driver rear-ending a Waymo. Three others involved a human-driven car running a red light before hitting a Waymo. There were no serious crashes where a Waymo ran a red light, rear-ended another car, or engaged in other clear-cut misbehavior.