Self-driving vehicles should not make the same errors or dumb decisions as human motorists. They should not speed. They will not drive drunk. They cannot succumb to distractions.
In terms of preventing crashes and eradicating a scourge of traffic deaths, that should be the easy stuff.
A more vexing question is this: Can self-driving vehicles account for errors made by other road users and respond in a way that avoids collisions?
Waymo has provided the start of an answer. In a first-of-its-kind study, the company's researchers and others reconstructed real-life crashes that occurred in Waymo's metro Phoenix operating area. Using its simulation tools, the company substituted its self-driving system for the road actors involved.
Overall, Waymo found its system would have avoided a collision in 84 of the 91 scenarios it studied. Perhaps no surprise: In the 52 situations where the self-driving system replaced the instigator of the crash, Waymo's system prevented 52 crashes.
Yet the scenarios in which Waymo's driver played the "responder" role, those in which it attempted to steer clear of an errant driver, are the more insightful part of the in-house analysis. Waymo's autonomous system avoided collisions in 32 of those 39 scenarios. It lessened the severity of crashes in four of the remaining seven scenarios.
"It's not good enough that you follow the rules of the road, because other people will still violate them and cause problems," said Steve Shladover, research engineer at California Partners for Advanced Transportation Technology, part of the University of California-Berkeley. "So that was a very good part of the study, that they separated those roles. It recognizes you have to coexist with other road users."Even in the most optimistic projections, self-driving vehicles will take more than a decade to reach the road in meaningful numbers — and then it will take further time for fleet turnover to render the majority of vehicles on the road autonomous.
With 92 percent of these "responder" crashes avoided or mitigated, Waymo's findings clarify the potential for self-driving technology to decrease traffic deaths and injuries during a long period in which human and robot drivers must coexist on the road. It's perhaps a more insightful data point than the one self-driving tech companies like to cite, a federal government study that finds 94 percent of crashes are the result of human error.