Autonomous vehicles only have to be a little bit better than human drivers before becoming widely used in the United States. This approach could save thousands of lives annually, even before the technology is perfected, according to a new RAND Corporation report.
Allowing wide use of autonomous vehicles when they are only 10 percent better than current American drivers could prevent thousands of road fatalities over the next 15 years and possibly hundreds of thousands of fatalities over 30 years, researchers found, compared to waiting until they are 75 percent or 90 percent better.
Given the uncertainties about the future of autonomous vehicle performance and use, the calculations were made by estimating road fatalities over time under hundreds of different plausible futures and different safety requirements for autonomous vehicle introduction.
"Our work suggests that it is sensible to allow autonomous vehicles on America's roads when they are judged to be just moderately safer than having a person behind the wheel," said Nidhi Kalra, co-author of the study and director of RAND's San Francisco office. "If we wait until these vehicles are nearly perfect, our research suggests the cost will be many thousands of needless vehicle crash deaths caused by human mistakes. It's the very definition of perfect being the enemy of good."
Developers of autonomous vehicles are testing the cars in cities like San Francisco and Pittsburgh, while federal lawmakers are considering a variety of new regulations and updates to existing regulations to govern their deployment and encourage their use. But the researchers don’t know how good the vehicles have to be before they are made available for use to all consumers.
The allure of driverless cars is based partly on convenience and partly on the potential to eliminate costly human errors, like distracted, drunk or tired driving. More than 90 percent of crashes involved driver-related errors, according to the National Highways Traffic Safety Administration.
Researchers acknowledge that if autonomous vehicles are proven to be safer than the average human driver, the vehicles would still cause crashes. They remain vulnerable to other hazards, like inclement weather, complex traffic situations, and cyber-attacks.
"This may not be acceptable because society may be less tolerant of mistakes made by machines than of mistakes made by people," said David Groves, study co-author and co-director of RAND's Water and Climate Resilience Center. "But if we can accept that early self-driving cars will make some mistakes -- but fewer than human drivers -- developers can use early deployment to more rapidly improve self-driving technology, even as their vehicles save lives."
Kalra hopes the study will enable policymakers and the public to better weigh potential risks and benefits of autonomous vehicles. Key considerations include how to measure the safety of the vehicles and what should constitute a passing grade.
The report builds on past research that found road testing under real traffic conditions is impractical for proving autonomous vehicle safety prior to deployment because it would take decades or longer to drive the requisite miles.
Traffic accidents pose a public health crisis. According to the National Safety Council, car crashes cause more than 35,000 fatalities and 2.4 million injuries in 2015. The council projecting 2016 would be deadlier, with 40,200 fatalities.
The report is available at on the RAND site.