### Waymo’s Safety Record: An In-Depth Examination of Autonomous Vehicle Incidents
On a Friday night in November 2023, a police pursuit in San Francisco culminated in a dramatic accident involving several vehicles, including a driverless Waymo robotaxi. Although the event led to injuries among pedestrians and other drivers, the Waymo vehicle remained unharmed, with no passengers inside. This incident, while regrettable, raises a crucial question: Are autonomous vehicles like Waymo enhancing the safety of our roads?
Waymo, a division of Alphabet, has been leading the way in the development of autonomous vehicles (AVs) for several years. With more than 22 million miles covered by its self-driving cars, the company has gathered substantial data on their performance in real-world scenarios. As Waymo expands its robotaxi operations, now delivering over 100,000 rides weekly, the firm has made new data available to assist the public in assessing its safety performance.
### The Figures: Waymo Versus Human Drivers
As of June 2024, Waymo’s driverless cars have been part of 20 accidents that resulted in injuries. While 20 injuries may seem significant, it’s essential to view this in context. With over 22 million miles traveled, Waymo’s vehicles have been associated with fewer than one crash leading to injury per million miles driven. This statistic is markedly better than the average human driver.
Waymo estimates that human drivers in San Francisco and Phoenix—its two principal markets—would have been responsible for 64 injury-related crashes over the equivalent distance. In stark contrast, Waymo’s vehicles were implicated in only 20 such accidents, indicating they are involved in injury-causing crashes less than one-third as frequently as human-driven vehicles.
The statistics become even more striking when we consider severe crashes, such as those resulting in airbag activations. Waymo’s driverless cars have encountered just five incidents where airbags were deployed, compared to an estimated 31 for human drivers over the same distance. This implies that Waymo’s vehicles are one-sixth as likely to be in a crash severe enough to activate an airbag than their human counterparts.
### The Context of Waymo’s Crashes
It’s not only the frequency of crashes that is important, but also the circumstances surrounding them. Of the 23 most serious incidents involving Waymo vehicles, 16 were rear-end collisions caused by human drivers hitting the Waymo from behind. In three additional cases, a human driver proceeded through a red light before colliding with a Waymo. Remarkably, there were no serious incidents where a Waymo vehicle ran a red light, rear-ended another vehicle, or participated in obvious reckless behavior.
These figures suggest that Waymo’s autonomous vehicles are typically not to blame for the incidents in which they become involved. In fact, many of these incidents appear to stem from human drivers’ errors, such as not stopping in time or disregarding traffic lights.
### Analyzing the Most Serious Incidents
Waymo has reported nearly 200 accidents as of June 2024, translating to roughly one crash for every 100,000 miles driven. However, the majority of these incidents were minor, with 43 percent involving a delta-V (a metric for the change in velocity during a crash) of under 1 mph—essentially minor bumps.
Focusing on the 23 most severe accidents that either resulted in injury or triggered airbag deployment gives a clearer view of Waymo’s safety performance. Here’s a breakdown of these incidents:
– **Rear-end collisions**: 16 incidents included a human driver colliding with a Waymo vehicle from behind. Some were serious enough to trigger airbag deployments, with one leading to a moderate injury.
– **Red-light infractions**: In three situations, a human driver ignored a red light and crashed into a Waymo. One such accident occurred during a police pursuit, and another involved suspects fleeing from a robbery.
– **Sideswipes**: Two incidents featured a vehicle in an adjacent lane sideswiping a Waymo. In one instance, an SUV overtook a Waymo and then abruptly cut in front, leading to a collision.
– **Left-turn collisions**: In two cases, another vehicle made a left turn across the path of a Waymo, resulting in a crash. In both instances, visibility was compromised by other traffic, making it challenging for the Waymo to evade the collision.
While there may be instances where Waymo’s vehicles could have taken greater measures to avoid some collisions, it is evident that, in most situations, human drivers bore the principal responsibility.
### Are Waymo’s Vehicles Truly Safer?
One must exercise caution when considering a company’s self-reported statistics, particularly when it has a strong incentive to present itself favorably. To gain an external viewpoint, I consulted with Noah Goodall, a civil engineer specializing in roadway safety. Good
