ROAD TRIPS. DRIVE-THROUGHS. Shopping malls. Freeways. Car chases. Road rage. 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 tell us about “zero crashes, zero emissions and zero congestion.”. AV’s, their champions argue, can offer all the advantages of cars without the drawbacks.
In particular, AV’s 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. 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. AV’s would let riders text (or drink) to their heart’s content without endangering anyone.
Evidence that AV’s 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. AV’s have superhuman perception and can slam on the brakes in less than a millisecond. 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 thousand fold 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).
To take advantage of much lower operating costs per mile, most AV’s are almost certain to be electric, which will reduce harmful emissions of two kinds: particulates, which cause lung and heart diseases, and climate-changing greenhouse gases.
Even electric vehicles, however, still cause some particulate emissions from tyre and road wear. Also the drop in greenhouse-gas emissions depends on how green the power grid is. The switch to electric vehicles will require more generating capacity and new infrastructure, such as charging stations and grid upgrades. For urban dwellers, the benefits will be better air quality and less noise.
Whether AV’s will be able to reduce congestion is much less clear. The lesson of the 20th century is that building more roads to ease congestion encourages more car journeys. If robot axis are cheap and fast, people will want to use them more. Yet there are reasons to think that the roads would become less crowded. Widespread sharing of vehicles would make much more efficient use of road space; computer-controlled cars can be smart about route planning; and once they are widespread, AV’s can travel closer together than existing cars, increasing road capacity.
Yet to think about AV’s as a fix for the problems caused by cars is to risk falling into a familiar historical trap. This is exactly how people thought about cars when they first appeared: as a fix for the problems caused by horses. In the 1890s, big cities around the world were grappling with growing volumes of horse manure and urine and the rotting bodies of thousands of dead horses, spreading disease.
A watchful eye
What unintended consequences might there be? One much-heralded benefit of AV’s is that they will offer freedom and independence to people who cannot drive cars: the very old, the very young and the disabled. Such vehicles are already ferrying around people in retirement communities, and one of Google’s videos shows a blind man doing errands in an autonomous car. But AVs could also encroach on freedom by invading people’s privacy. Robotaxi operators will chronicle their riders’ every move, so they will end up knowing a great deal about them. Some taxis already record riders for security reasons; robotaxi will surely surveil both their passengers and their surroundings to protect themselves. Police investigating a crime will ask AV’s in the vicinity what they saw.
If people no longer drive cars, one consequence may be new forms of segregation, notes Ms Hart. Access to some places may be restricted to certain riders, just as some online services cannot be accessed on all devices.
She thinks there may be a need for a physical equivalent of “network neutrality” rules. These rules are to ensure that all locations are equally accessible to all AV’s. In authoritarian societies, AV’s could be a powerful tool of social control.
AVs could also trigger a shortage of organ donors. Many of these organ donors are young people killed in car accidents and a drop in smoking (more than half of all tobacco sales in America are made at petrol stations, which will vanish, notes Mr Evans).
And if cars are no longer symbols of independence and self-definition for the young, other things will have to take their place.
Like cars before them, AVs will change the texture of everyday life.