Study: Waymo Self-Driving Taxis Have 68% Fewer Accidents Than Human Drivers

On July 26, the Insurance Institute for Highway Safety (IIHS) released a study analyzing the safety performance of Waymo’s autonomous taxis between 2021 and 2024. The research drew on approximately 50 million miles of driverless vehicle operation data from Waymo across four cities—Phoenix, San Francisco, Los Angeles, and Austin—as well as federal crash reports from the same period. The findings showed that Waymo vehicles were involved in crashes at a rate of 1.28 per million miles, compared to 4.06 for human-driven vehicles—a 68% lower crash rate for Waymo. Most crashes involving Waymo were minor in severity and typically not attributed to the autonomous vehicle’s fault. By city, crash rates were 76% lower in Phoenix, 71% lower in Los Angeles, and 35% lower in San Francisco. In Austin, however, Waymo’s crash rate was slightly higher than that of human drivers, which the study suggested might be due to a smaller sample size of test miles in that city. The study noted that Waymo does not operate on highways, where crash rates are generally lower than on city streets. If highway miles were excluded from the comparison, the overall crash rate for human drivers would be even higher. Additionally, nearly half of Waymo’s crashes occurred on streets with speed limits under 25 mph, compared to only 8% for human-driven vehicles. The low-speed environment likely contributed to reduced crash severity. Notably, despite being equipped with radar and lidar, Waymo vehicles had a higher proportion of crashes occurring in dark conditions compared to those driven by humans.