Cars changed the world in all sorts of unforeseen ways. They granted enormous personal freedom, but in return they imposed heavy costs. People working on autonomous vehicles generally see their main benefits as mitigating those costs, notably road accidents, pollution and congestion. GM’s boss, Mary Barra, likes to talk of “zero crashes, zero emissions and zero congestion.” AVs, their champions argue, can offer all the advantages of cars without the drawbacks.
In particular, AVs could greatly reduce deaths and injuries from road accidents. Globally, around 1.25m people die in such accidents each year, according to the WHO; it is the leading cause of death among those aged 15-29. Another 20m-50m people are injured. Most accidents occur in developing countries, where the arrival of autonomous vehicles is still some way off. But if the switch to AVs can be advanced even by a single year, “that’s 1.25m people who don’t die,” says Chris Urmson of Aurora, an AV startup. In recent decades cars have become much safer thanks to features such as seat belts and airbags, but in America road deaths have risen since 2014, apparently because of distraction by smartphones. AVs would let riders text (or drink) to their heart’s content without endangering anyone.
Evidence that AVs are safer is already building up. Waymo’s vehicles have driven 4m miles on public roads; the only accidents they have been involved in while driving autonomously were caused by humans in other vehicles. AVs have superhuman perception and can slam on the brakes in less than a millisecond, compared with a second or so for human drivers. But “better than human” is a low bar. People seem prepared to tolerate deaths caused by human drivers, but AVs will have to be more or less infallible. A realistic goal is a thousandfold improvement over human drivers, says Amnon Shashua of Mobileye, a maker of AV technology. That would reduce the number of road deaths in America each year from 40,000 to 40, a level last seen in 1900. If this can be achieved, future generations may look back on the era of vehicles driven by humans as an aberration. Even with modern safety features, some 650,000 Americans have died on the roads since 2000, more than were slain in all the wars of the 20th century (about 630,000).