Majority of Waymo Collisions Caused by Human Drivers in the Other Vehicle

I have already talked about crashes and the crash rates of autonomous cars here several times, not least those of Waymo compared to human drivers. Now Waymo has published more data on accident rates and driving performance, with some interesting details.

Since the start of robotaxi operations in San Francisco, Phoenix, Austin and Los Angeles, Waymo has completed more than 22 million miles (over 35 million kilometers) of rider-only driving, with Phoenix leading the way with 15.399 million miles (24.6 million kilometers), San Francisco in second place with 5.931 million miles (9.5 million kilometers), followed by Los Angeles with 855.000 miles (1.4 million kilometers) and Austin with 14,000 miles (22,400 kilometers).

Compared to human drivers, the Waymos resulted in 84 percent fewer airbag deployments, 73 percent fewer injuries and 48 percent fewer accident reports, regardless of who was at fault for the accident. It should be noted that any involvement of a driverless robotaxi in a collision must be reported to the traffic authorities and the police, which is not the case with human drivers. As shown in the following graph, it is estimated that only a third of all collisions are reported to the police.

Of the almost 200 accidents reported, only 20 resulted in injuries. In comparison, human drivers caused 64 accidents with injuries. Only one of the 20 injuries was considered serious. Interestingly, however, this one serious injury was caused by the human driver who had fled from the police and collided with two other vehicles after a chase, one of which was the Waymo and damaged it. The injuries were sustained by pedestrians who had been hit by the fleeing car. No one in the Waymo itself was injured.

This means that Waymos were only involved in one accident per million miles (over 1.6 million kilometers) in which someone was injured. However, of the 23 most serious accidents involving Waymos, 16 were caused by a human driver ramming into a Waymo from behind, three were caused by human drivers running a red light, and two involved the Waymo being struck by a vehicle in the adjacent lane that had crossed the lane marker and entered the Waymo’s lane. In the last two accidents, an oncoming vehicle turned left in front of the Waymo and hit the Waymo.

There were no serious accidents involving a Waymo running a red light, hitting another car or other clear misbehavior. With just under 200 accidents involving Waymo, there was one accident for just over 100,000 miles (160,000 kilometers).

Even the accidents involving Waymo happened at very low speeds. In 43 percent of the accidents in Phoenix and San Francisco, the delta-V, i.e. the measured change in speed in the event of a collision, was less than 1 mile per hour (less than 1.6 kilometers per hour), which usually only results in small dents or scratches, such as those caused by parking damage.

More details can be found on the Waymo website.

This article was also published in German.