After a brutal 2023The vibe around self-driving cars is improving. Cruise, the industry leader whose vehicle was involved in technology/2023/11/08/cruise-crash-driverless-recall/”>A horrible accident in San Francisco Last fall, there was Restarted under new management, while rival Waymo is expanding to serve broader swaths of the Bay Area and Los Angeles and Tesla is promising a new robotaxi service.
Although Americans say that tech/americans-dont-trust-self-driving-cars-want-improved-drivers-ed-instead-study”>Stay cautious Proponents of autonomous driving insist there is nothing to fear. In fact, they envision roads full of self-driving cars that are safer and cleaner than current ones, a tempting prospect in a country where transportation is the priority. The largest source of greenhouse gas emissions and the residents are several times more likely to die in an accident than those living in other rich nations.
As appealing as these arguments are, there is a logical flaw in them. As a classic 19th-century theory known as Jevons' paradox explains, even if autonomous vehicles were to work perfectly (a big “if”), they would likely be increase total emissions and deaths from accidents, simply because people will use them too much.
In the 19th century, coal was the sine qua non condition Coal is an essential element of economic development, essential for everything from heating to transportation to industry. In Britain, the country where coal first fueled an industrial revolution, national leaders debated how much concern they should have about the possible depletion of coal deposits. Some argued that the supply would never run out because improvements in steam engine designs would steadily reduce the amount of coal needed to power a train, make a dress, or anything else. Productivity gains would allow Britain’s coal resources to be stretched ever further.
In his 1865 book The coal questionEconomist William Stanley Jevons explained why he disagreed. Jevons drew on recent history at the time to show that the efficiency of steam engines had led people to use them in greater numbers. “Burning coal became economically viable, so demand skyrocketed,” said Kenneth Gillingham, a professor of environmental and energy economics at Yale. “Steam engines are everywhere, and people are using them instead of water power. In fact, much more coal is used than at the beginning.” Despite improvements in steam engine design, Jevons argued, total coal use would continue to rise.
“Burning coal became an economically viable activity, so demand skyrocketed”
Today, Jevons' paradox describes a situation in which increased efficiency in the use of a resource (such as water, gasoline, or electricity) causes demand for that resource to skyrocket, thereby offsetting an expected decrease in total use. technology/2010/08/26/not-such-a-bright-idea”>Electric lights They are often cited as an example: people have responded to the improved efficiency of incandescent light bulbs installing many more of them that there has been no decrease in the total energy consumed by lighting. Jevons' paradox has become a fundamental principle of environmental economics, used to explain why efficiency improvements can backfire and cause the opposite result to that intended.
Their lessons can also shed light on transportation. Consider the Projects carried out by highway agencies to relieve traffic congestion.Public officials often justify them by pointing out that (exactly) that gasoline engines are less efficient and release more pollutants if they get stuck in a traffic jam instead of moving at a steady pace. For that reason, they argue, highway expansions or traffic technologies that alleviate traffic jams will also reduce emissions.
Photograph by Patrick T. Fallon / AFP via Getty Images
The Jevons paradox reveals a blind spot in such claims. If an additional lane or new traffic technology relieves congestion, more people will decide to drive because of a reduction in the “cost” of using a car (in this case, waiting time in traffic). Even if each car now produces fewer emissions due to the increased travel speed, these benefits could be dwarfed by the large number of new trips that would not have otherwise occurred. In other words: a self-defeating effect. (The benefits of expanded highways are even more questionable when one considers the likelihood that increased car volume will ultimately force traffic to shift.) as slowly as before —Only now, with more cars belching smoke as they crawl along. This phenomenon is known as induced demand.)
Now consider the case of autonomous vehicles. In an attempt to win the support of skeptical regulators and the public, proponents of autonomous vehicles frequently cite the technology/2023/07/cruise-autonomous-vehicles-safety-waymo-self-driving-cars-ad-new-york-times.html”>alleged security benefits Some suggest that autonomous vehicles will reduce energy consumption and emissions by avoiding the quirks of human driving that compromise engine efficiency. “The higher the proportion of autonomous vehicles on the road, the smoother the overall flow of traffic should be, resulting in less energy-intensive stop-and-go traffic,” Predicted a Mobileye blog post for 2021a technology company that claims to be “driving the evolution of autonomous vehicles.”
Jevons' paradox has become a fundamental principle of environmental economics.
Both of these supposed benefits are dubious; AV computers can make driving mistakes that humans would not makeand even if they run entirely on electricity, their software, hardware and sensors It requires a huge amount of energy that generates its own emissions as it is produced.Still, it's reasonable to expect that the reliability and efficiency of autonomous vehicles will improve over time. For the sake of argument, let's risk our lives and assume that the average autonomous vehicle will end up being safer and cleaner than one driven by a human. Will emissions and overall deaths from accidents then decline?
Jevons' paradox suggests that we should not count on it.
As AV companies Advertisements show, the reason for being The advent of autonomous vehicles is making driving easier and more enjoyable, freeing passengers to meet at work, sing a song or take a nap. How do people react when an activity becomes less burdensome and more fun? They do it more often.
Similar to the expansion of highways, the availability of autonomous vehicles will likely lead people to take longer trips in motor vehicles or opt for a car when they would otherwise have used public transportation, cycled, or stayed home. The result will be that there will be many more (now autonomous) cars on the roads. As University of Virginia historian Peter Norton wrote in an article Prophetic Article of 2014Self-driving technology could lead to people “spending more total time in vehicles (and) using them for even more tasks.”
Norton, who teaches the Jevons paradox in his classes, told me he wrote that article because “I was watching smart engineers argue, to my utter astonishment, that efficiency[from autonomous vehicles]would only bring savings, with no offsetting costs. I don’t understand how they can continually deny this elementary fact.”
How do people react when an activity becomes less burdensome and more fun? They do it more often.
In support of his point, a recent article A Transportation Research Board study concluded that “the likelihood of making additional trips increases” when autonomous vehicles are available, even if they are shared rather than owned. Since each autonomous mile creates some pollution and transport some risk of death from an accident, the increase in total driving will offset theoretical improvements in climate or safety over a single identical trip made by humans.
The social impact of self-driving cars appears even worse when one considers the second-order effects related to land use. As well as the increase in car ownership, fed In the 20th century, with suburbanization, autonomous vehicles could lead people to move to larger, less energy-efficient homes in urban fringes, where (now more tolerable) car trips are longer.
Right now, there are more questions than answers about the collective effects of autonomous vehicles, which are currently available in only a handful of U.S. cities. Billions of dollars As they advance their technology, it’s impossible to know how safe and energy-efficient their products will be. But Jevons’ paradox suggests that those aren’t the only questions to consider. There’s another, equally crucial one: how much more will autonomous vehicles drive, and will those extra miles offset any potential benefits?
