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 (AV) generally see their main benefits as mitigating those costs, notably road crashes, 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 crashes. Globally, around 1.25 million people die in such crashes each year, according to the WHO; it is the leading cause of death among those ages 15 to 29. Another 20 million to 50 million people are injured. Most crashes occur in developing countries, where the arrival of autonomous vehicles is still some way off.
But evidence that AVs are safer is already building up. Waymo's vehicles have driven 4 million miles on public roads; the only crashes that 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, said Amnon Shashua of Mobileye, a maker of AV technology. That would reduce the number of road deaths in the United States each year from 40,000 to 40, a level last seen in 1900.
Building efficiencies?
Whether AVs 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 robotaxis 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, AVs can travel closer together than existing cars, increasing road capacity.