A Driverless World

Friction-free personal mobility

One of the great unknowns about driverless cars is whether their convenience will worsen traffic congestion and its accompanying evils. An optimistic scenario would be that driverless cars will improve the efficiency of urban transportation systems, and hence reduce private vehicle ownership, thereby reducing congestion and therefore reducing the size of a city’s carbon footprint that’s related to transportation. Another, less environmentally friendly scenario is that as people embrace the convenience of friction-free mobility, driverless cars will wind up actually logging more vehicle-miles per year on average, leaving a larger carbon footprint.

Convenience can be a double-edged sword. People are drawn to convenience like iron filings to a magnet. Sometimes, however, convenience carries with it a price: unexpected and negative consequences. The friction-free personal mobility offered by driverless cars might solve the worst excesses already inflicted on us by automotive technology. Or, the hidden cost of convenient personal mobility might be that an ever-growing number of people casually rack up their number of miles driven.

Economists call the unforeseen reduction of expected gains from new technologies owing to increased usage the rebound effect. It’s not clear whether driverless cars will have a rebound effect on traffic, increasing the number of miles that people travel each year, and the number of cars on the roads. Some research paints an optimistic picture, in which city streets will be emptier of vehicles in a few decades. In an interview with the Economist, Luis Martinez of the International Transport Forum, a think tank dedicated to transportation policy, predicted that fleets of self-driving vehicles could replace all vehicular public transportation taxi and bus trips in a city, providing as much mobility but with far fewer vehicles.¹

To test this theory, Martinez created an agent-based model to simulate daily travel patterns in a medium-sized European city. Using several years of actual data from previous transportation surveys, he calculated that if city inhabitants used fleets of shared autonomous taxis rather than privately owned cars and public transportation, the number of vehicles on the city’s roads could be reduced by 90 percent.² While fleets of autonomous taxis would drastically reduce the number of cars on the streets, the simulation also predicted that the overall number of vehicle-miles traveled per car would increase slightly because the self-driving taxis would shuttle back and forth more frequently to pick up passengers.

A report from the University of Michigan Transportation Research Institute supports these findings. The report concludes that the adoption of autonomous vehicles would reduce the number of cars owned by the average U.S. household from just over two to one vehicle per household.³ According to the report, one-vehicle households will be made possible because self-driving vehicles will use a “return-to-home” mode after they drop one household member at work so other household members can use the family self-driving car to be shuttled to errands and activities.

There’s a catch, however. Although a family’s driverless car can transport family members efficiently back and forth, the fact that one car is supporting more people would result in higher per-vehicle mileage. Although the average household of the future might own fewer cars, the remaining driverless car will be used 75 percent more frequently, accumulating an average of 20,406 annual miles per vehicle per year. The upside of this finding is that even if a single driverless vehicle were to rack up 75 percent more miles on average, the mileage for the entire household would still be lower than if two human-driven cars were in use.

One potential risk of having a single driverless car support an entire household is that the increase in per-vehicle mileage ends up being more than the predicted 75 percent. There’s no doubt that summoning a driverless car to pick you up and drop you off would be a great convenience. However, an unintended negative consequence of more efficient transportation could be that a driverless vehicle will drive significantly more miles than would the equivalent human-driven vehicle.

Ideally, an empty self-guided car would find a safe place out of the way of traffic to sit and await its next summons. If that safe place were several miles away, however, the car would be forced to drive itself back and forth a great distance rather than just parking nearby. Its mileage would increase, and its wasteful shuttling would make traffic congestion and air pollution even worse.

If the availability of too-convenient transportation creates a rebound effect on traffic and dramatically increases the number of road miles that people travel each year, driverless cars could have a devastating environmental impact. Today the transportation sector is already one of the largest contributors to air pollution. In the United States alone, exhaust from cars and trucks causes an estimated 29 percent of the greenhouse gas emissions that human activities generate each year.⁴ If driverless cars were to increase the number of vehicle miles traveled per capita, densely populated “megacities” in developing nations would be hit particularly hard.

While the United States has a nearly 100-year-old relationship with the car, other nations are enthusiastically catching up. China is following in the footsteps of the United States, gaining its own car culture. As a growing and newly affluent Chinese middle class embraces the convenience of car travel, cities such as Beijing and Zhengzhou are suffering from spectacular eight-lane traffic jams and worsening smog levels.

Today, the ratio of cars per person is still lower in China than in the United States or Europe, averaging 85 vehicles per 1,000 people (compared to 797 vehicles per 1,000 people in the United States.)⁵ However, the rate at which the Chinese auto industry manufactures and sells new cars continues to skyrocket, increasing at an annual rate of 7 percent since 2013.⁶ Perhaps Chinese car culture will sidestep some of the worst excesses of car culture by adopting driverless cars sooner, rather than later. To tame the traffic beast, Baidu, the Chinese search engine company some describe as the Google of China, is working together with BMW to develop autonomous vehicles that are familiar with Chinese roads.

In both developing and developed nations, traffic jams are a major source of air pollution. In the United States alone, as commuters inch forward in traffic jams, their idling cars waste 2.9 billion gallons of gasoline each year, enough to fill four football stadiums.⁷ Only time will reveal whether driverless cars will produce less pollution, or whether their use will entice people to log an ever-growing number of miles each year, further degrading air quality and making urban traffic jams even worse.

Another environmental side of effect of driverless cars could be shorter vehicular lifespans. A car’s longevity is indicated by its odometer. According to Consumer Reports magazine, today the typical life span for a personal vehicle is about 150,000 miles which means that on average, over the course of eight years, that car will be driven about 18,750 miles per year. In comparison, since it drives roughly 70,000 miles a year, the lifespan of the average New York taxi cab is only 3.3 years.⁸

It remains to be seen whether the introduction of driverless cars will ease the negative effects inflicted on us by the modern automobile. If the University of Michigan research is correct and a driverless car racks up 20,406 miles each year, the average family car would be “used up” more quickly, reaching its lifetime expectancy of 150,000 miles in just over seven years of use. One worst-case scenario would be a future in which used-up driverless cars litter the landscape, filling junkyards and backyards with decommissioned auto bodies and worn-out engines. History has taught us, however, that new technologies do not merely extend a former status quo. Driverless cars have several characteristics that could change their potentially gloomy and environmentally devastating trajectory.

If the internet of the 1990s were suddenly forced to absorb today’s data traffic, it would buckle under the load. Over the years, several enhancements have enabled the modern internet to absorb new users and handle an increasing amount of data, including better compression technologies, fiber-optic cable, and more intelligent routers. Similarly, improvements in technology could also ease the potentially negative rebound effect caused by driverless cars. Several research studies support such an optimistic view.

First, let’s address the issue of vehicular lifespan. A report from McKinsey calculates that driverless cars will be able to brake and accelerate more gradually, resulting in fuel savings of 15 to 20 percent and a reduction of CO₂ emissions of 20 million to 100 million tons per year.⁹ If McKinsey’s research is correct, then smoother driving would increase a driverless vehicle’s longevity.

Not only would driverless cars last longer, they could be built specifically to achieve longevity. There’s nothing sacred about a lifespan of 150,000 miles. If there were a market for it, car companies could design driverless cars that could drive for several hundred thousand miles. City transit operators expect their buses to have a useful lifespan of at least twelve years and 250,000 miles.¹⁰ Semitrailers are designed to operate for 1,000,000 miles and their engines are designed to run virtually nonstop.¹¹ Rail cars last even longer: some of the original BART cars in San Francisco, built in 1968, are still in operation today.

Even if their lifespan remained the same as today’s human-driven cars, driverless cars could milk more capacity out of existing roads. To decrease their wind resistance, cyclists ride behind one another in a closely spaced line, an energy-saving strategy known as drafting. Fleets of driverless cars and trucks could use a similar approach and save energy by driving behind one another in tight formation, a fuel-saving strategy known as platooning.

Platooning saves fuel both by reducing wind resistance and using road “real estate” more efficiently. Human-driven cars don’t use the space on the road very efficiently. People have to drive several hundred feet apart for safety and we aren’t very adept at smoothly changing lanes. In contrast, platoons of driverless cars would use road space more effectively, resulting in less congestion at the places where traffic jams regularly form, such as highway on-ramps and off-ramps, before lane changes, and at intersections.

A study by researchers at the University of Texas estimates that if 90 percent of the cars on the road in the United States were self-driving, it would be equivalent to doubling road capacity. Texas researchers predict that tightly spaced platoons could reduce congestion-related delays by 60 percent on highways and by 15 percent on suburban roads.¹² Trucks, because of wind resistance, are particularly prone to fuel inefficiency. Platoons of autonomous trucks spaced fewer than three feet apart while driving would reduce fuel consumption by 15 to 20 percent per truck.¹³

Another potential environmental benefit lies in rethinking car design. If driverless cars become substantially safer than those driven by humans, automotive designers could dramatically improve upon a mechanical body whose shape and size is the compounded result of a century’s worth of incremental improvements and creeping crash-safety requirements. As accident rates drop significantly, driverless cars could be lighter and smaller, and therefore more fuel efficient.

Figure 2.2 A depiction of a revitalized city where autonomous taxis have brought an end to traffic jams.

Source: Granstudio

Driverless taxis would not be the only vehicles to shrink in size. The delivery of packages and food orders could be handled by tiny, lightweight autonomous delivery drones on wheels. On college campuses, pizza, the perennial U.S. favorite, would be delivered in plastic, wheeled autonomous “pizza drones,” baked to just the right consistency during the ten-minute journey. Contrast that with the nearly one-ton vehicle required to deliver a one-pound pizza today. Most of that ton of weight is for the benefit of the human driver, not for the pizza.

One core characteristic of cars that could be improved upon is how they’re powered. Driverless cars will likely have electric engines. One of the barriers to the adoption of electric-only cars has been a lack of widely available methods for charging the car’s battery. Tesla has overcome this limitation by building its own recharging infrastructure. As cars become intelligent enough to plan their journeys to include pit stops at charging stations, much of the uncertainty associated with an engine that needs regular recharging will be reduced.

A combination of energy-saving benefits, including platooning, lightweight car bodies, efficient driving, and rechargeable batteries will minimize some of the negative effects of driverless cars. Another environmentally degrading activity that most of us participate in on a daily basis is parking. Driverless cars will improve city life by reducing cruising, the tedious circling that drivers do when in search of a parking space, and by doing away with the need for parking lots altogether.

Parking

It’s difficult to pinpoint why, exactly, a particular city is considered charming. Similar to the debate about what constitutes art, a city’s appeal is a factor that people can’t easily explain, but they recognize it with certainty when they experience it. In our experience, cities that are appealing places to visit, live in, and work in are those that enjoy a vibrant pedestrian culture. The more people walking the streets, the more enjoyable a city’s sense of hustle and bustle, as well as the more money that will exchange hands in the streets’ stores and restaurants.

The shape of a city’s parking lots has a surprisingly powerful effect on its personality. Older east-coast cities in the United States, as well as many cities in Europe, were designed and developed before the widespread use of cars. Those older cities have a significantly different vibe than newer cities that developed after cars became ubiquitous. This feeling of old city charm is often called walkability. Needless to say, parking lots don’t increase a city’s walkability, nor its charm.

Parking guru Donald Shoup describes the high hidden cost of searching for on-street parking as an activity that “congests traffic, causes accidents, wastes fuel, pollutes the air, and degrades the pedestrian environment.”¹⁴ Although estimates vary, people spend anywhere between 3.5 and 14 minutes circling in search of free curbside parking, contributing significantly to the congestion of downtown traffic. Shoup’s recommendation for curing downtowns of the negative side effects of cruising is to raise the price of curbside parking. An even more effective way to reduce cruising would be to eliminate downtown parking altogether.

Like plaque clogging arteries, parked cars clog our streets. The typical parked car consumes, on average, 14 square meters of pavement.¹⁵ It eats up even more space if you factor in the access road leading up to the parking spot, which makes the total footprint for a single parked car 100 square meters large. On average, cars remain parked 95 percent of the time.¹⁶ That’s a lot of wasted space.

Cars are greedy. Most require multiple parking spots: one at home, one at work, and, sometimes, an additional parking place after work if the car’s owner goes to the mall or the gym. These parking spots are rarely in use simultaneously: the one at home remains vacant while the car is parked at work.

Even more space is lost to parking when time is factored into the equation. In their classic text The Urban Transportation Problem (1965),¹⁷ authors John Meyer, John Kain, and Martin Wohl calculate that over its lifetime, the average car takes up twice as much space parked than when it is being driven. At first this conclusion doesn’t sound right; after some analysis, however, it makes sense.

Core to Meyer’s, Kain’s, and Wohl’s calculation is the idea of area hours, the notion that the land needed by cars is not just a matter of space, but a function of both space and time. Cars spend most of their time parked, on average, about twenty-three hours a day. As a result, parked cars consume significantly more area hours than do cars in use.

How did so much precious downtown real estate end up getting allocated to the inglorious purpose of storing cars? When it comes to designing cities, parking lots are widely accepted as a necessary evil. Although we might analyze and debate the construction of every new highway or public building, few dispute the need for parking lots.

Another reason for the prevalence of parking lots is that many cities mandate they be there. Most cities have strict zoning ordinances with minimum parking requirements. Zoning ordinances kick in when someone wants to build a new restaurant or apartment building and applies to the city for approval. To get the city’s permission to proceed, most municipalities require that a minimum number of new parking spaces are also constructed to accommodate the people using the new building or business.

Zoning ordinances requiring parking were originally well intended. After all, nobody enjoys circling around for parking. Yet, the unintended consequence of decades of mandated minimum parking requirements has been that modern towns and cities are riddled with dead space devoted to storing cars.

Another way to assess the staggering impact of car parking on the look and feel of modern towns and cities is to calculate a city’s total parking coverage rate, or the total amount of space dedicated to urban parking garages. In cities, many parking garages have multiple levels stacked on one another. Imagine how much area would be revealed if all the different levels of a city’s parking garages were “unrolled” and laid out flat.

The newer the city, the greater its slavishness to parking space. Downtown Los Angeles boasts 107,441 parking spots; if these spots were laid out in a two-dimensional plane they would add up to a surface area of 331 hectares, or 81 percent of the city’s entire downtown area of 408 hectares. Another city heavily dedicated to parking space is Melbourne, Australia, where parking spaces represent 76 percent of the total area of its downtown. In Houston, Texas, parking space represents 57 percent of its total downtown space. In older cities such as London and New York, parking eats up less of the downtown, about 18 percent.¹⁸ Cities with the least space dedicated to parking lots and structures were Bangkok (8 percent), Tokyo (7 percent), and Manila (2 percent).

If cars suddenly no longer needed to park downtown, city planners would find themselves with a huge blank canvas of unused space that could be constructively repurposed. Municipal codes, the local laws that dictate what sort of structures can be built where, could drop their requirement that each new business venture or residence be accompanied by the addition of a minimum number of new parking spaces. City planners could busy themselves with the more gratifying task of repurposing parking lots into human-friendly space. The result would be a new urban utopia. Or not.

At first glance, erasing parking lots from downtown areas sounds like a guaranteed cure for the evening doldrums that characterize many urban areas. Reforming parking lot space into parks, playgrounds, and sidewalk cafés would inject charm into dreary, sprawling downtowns, and perhaps create many new jobs. As people no longer cruised for a parking space, there would also be less traffic congestion.

Imagine how clean and beautiful cities could become. Without parking lanes, streets would instantly broaden into stately boulevards. With fewer cars circling in search of an elusive parking spot, the air would be fresher and cleaner. An optimist would conclude that driverless cars will enable all cities, even Los Angeles, to acquire some charm.

A more rational observer, however, would point out that the process of recouping large chunks of land formerly dedicated to parking space carries some risk. City dwellers and planners alike must figure out how to turn former downtown parking space into the equivalent of urban gold. The cities that will fare best in their liberation from parking will be those whose strategies are based on a broad and holistic view of the impact of driverless cars on the urban landscape.

The health of a city’s downtown depends on a number of variables. One key question is how much of a city’s budget inflow comes from revenue earned from parking tickets and parking fees. If that money were to disappear, what condition would the municipal budget be in?

Other variables that demand exploration include the density and composition of the local population. If downtown parking lots were turned into appealing new housing units and businesses, would enough people be willing to live in these new homes? Would these residents spend enough money to keep the new businesses afloat? Finally, what would prevent the emptying suburbs outside the city from becoming ghost towns?

Transforming parking space into usable residential and commercial space will be one challenge cities must resolve. Another unintended consequence of friction-free personal mobility is that vibrant city centers might spiral into a slow decline. In his gargantuan tome of parking lore, The High Cost of Free Parking,¹⁹ Donald Shoup tells a cautionary tale of the unintended impact of a new six-story parking garage built directly underneath a concert hall in downtown Los Angeles.

During the years between 1987 and 2003 while Disney Hall and its parking structure were under construction, the city ran into financial hardship. The hall’s new parking lot contained spaces for 2,188 parked cars and cost the city $110 million to build, a cost that averaged out to roughly $50,000 per parking spot. Convinced that convenient parking was critical to the hall’s success, as construction costs exceeded the original budget, the city was forced to sell bonds to fund the enormous underground structure.

Los Angeles city planners argued that the high cost of Disney Hall’s parking garage would be quickly paid back by parking revenues earned once the garage was up and running. This assumption was based on the understanding that in order for the new underground parking lot to pay for its construction costs, the new concert hall would host at least 128 full-house performances a year. The irony that the concert hall ended up in service to the parking lot rather than the other way around was not the only cautionary tale associated with the project, however.

Another lesson that Los Angeles city planners learned from building a costly and super-convenient parking structure directly underneath a prime downtown attraction was that too-efficient parking can be as deadly for the health of a downtown as extremely inefficient parking. Since the parking garage was located directly under the hall, concert-goers stepped out of their cars and went right into the concert. As a result, they never set foot onto the streets outside the symphony hall. They emerged from the underground parking lot on escalators that deposited them grandly, like minor royalty, in an internal entrance near their seats.

The new concert hall may have drawn people to downtown Los Angeles, but these people didn’t stick around to dine in a nearby restaurant or patronize the local shops. Shoup describes the unintended consequence of a too-convenient underground parking lot. “Almost everyone prefers downtown San Francisco to downtown Los Angeles. … In Los Angeles, the sidewalks are empty and threatening at night. Even a spectacular new concert hall does not help to create a vibrant downtown if every concertgoer drives straight into its underground garage.”²⁰

If Shoup is correct, the streets near San Francisco’s Davies Symphony Hall enjoy lively pedestrian traffic in part because the hall’s parking lot is small (at 618 spaces) and is located a slight distance away. As a result of this slightly inconvenient transportation situation, people going to see a concert in San Francisco are forced to spend a little bit of time on the streets downtown. Regardless of whether concert-goers arrive via public transportation or walk a few blocks from where they parked, their presence adds vitality and energy to the streets outside the hall.

The lesson of the Los Angeles symphony hall is that every convenient new technology has hidden costs. Driverless cars will reduce the need for urban parking lots (a good thing), but their convenience could also reduce the enforced mingling that gives life (and revenue) to downtown shops and restaurants (a bad thing). If driverless pods dropped off pedestrians right outside their downtown destination with the punctuality and surgical precision of a military strike, the unintended hidden cost of such appealing efficiency could be the loss of lively and lucrative pedestrian foot traffic on downtown sidewalks.

Parking spaces are intimately interwoven into the geography of the modern urban downtown. In the coming decades, driverless cars will render parking lots obsolete, rearranging the shape of modern cities. Another side-effect of convenient personal mobility will be that people will go in search of new places to live.

Commuting

The greater metropolitan areas of cities such as Mumbai, Mexico City, and Shanghai are each home to more than 20 million people. By the year 2050, the size of the global urban population will nearly double, from today’s figure of 3.3 billion people to a projected 6.4 billion.²¹ These megacities will stretch for miles and their streets will be stuffed with cars as their citizens are forced to engage in a daily and potentially deadly attempt to get around.

As urban populations grow, cities will need to use their space wisely. When driverless cars become commercially available, forward-thinking city planners can repurpose urban parking lots as parks and affordable housing. Another way to improve the quality of urban life would be to make commuting to work easier.

People spend a large chunk of their day driving themselves to work. In the United States, the average commute time is roughly 30 minutes each way, an hour each day.²² On average, most people’s hour-long journey to work and back is usually made alone.

Table 2.1 In the U.S., the average commute to work is roughly half an hour.

New York-Northern New Jersey-Long Island	18,919,649	34.6
Los Angeles-Long Beach-Santa Ana	12,844,371	28.1
Chicago-Joliet-Naperville	9,472,584	30.7
Dallas-Fort Worth-Arlington	6,400,511	26.5
Houston-Sugar Land-Baytown	5,976,470	27.7
Philadelphia-Camden-Wilmington	5,971,589	28.6
Washington-Arlington-Alexandria	5,609,150	33.9
Miami-Fort Lauderdale-Pomano Beach	5,578,080	27.0
Atlanta-Sandy Springs-Marietta	5,286,296	30.3
Boston-Cambridge-Quincy	4,559,372	28.8
San Francisco-Oakland-Fremont	4,343,381	28.7
Detroit-Warren-Livonia	4,290,722	26.1
Riverside-San Bernardino-Ontario	4,245,005	30.6
Phoenix-Mesa-Glendale	4,209,070	25.8
Seattle-Tacoma-Bellevue	3,447,886	26.9
Minneapolis-St. Paul-Bloomington	3,285,913	24.8
San Diego-Carlsbad-San Marcos	3,105,115	24.1
St. Louis	2,814,722	24.8
Tampa-St. Petersburg-Clearwater	2,788,151	24.1
Baltimore-Townson	2,714,546	30.0
Denver-Aurora-Broomfield	2,554,569	26.5
Pittsburgh	2,357,951	25.9
Portland-Vancouver-Hillsboro	2,232,896	24.9
Sacramento-Arden Arcade-Roseville	2,154,583	26.2
San Antonio-New Fraunfels	2,153,891	24.6
Orlando-Kissimmee-Sanford	2,139,615	26.3
Cincinnati-Middletown	2,132,415	24.2
Cleveland-Elyria-Mentor	2,075,540	24.5
Kansas City	2,039,766	22.5

http://oldurbanist.blogspot.com/2012/07/commutes-tradeoffs-and-limits-of-urban.html

New forms of transportation change the way people perceive distance. In the 1950s, cars made it possible for people to conveniently commute into the city to work. Along with millions of other newly affluent New Yorkers, my grandparents joyously moved out of Manhattan to a suburb in Queens. To accompany their brand new home, they bought themselves an Oldsmobile, a car with the weighty appeal of a military tank that could barely squeeze into their one-car garage.

My grandparents left the city for several reasons. While a realtor might tell you that buying and selling a house is all about “location, location, location,” there are several additional factors that people weigh when deciding where to live. Most people choose their home according to its price and its proximity to their jobs (i.e., commute time) and the quality of the local schools. Even though people may try to settle somewhere near work, in order to find a home they can afford that meets their other criteria, they often wind up with a long and stressful commute to work.

Driverless cars will make it easier to commute, giving people more choice in where they buy their home. As future city streets become less congested and the number of residential spaces increases, more people will move into newly appealing downtowns. Those who don’t like city life will have the option to move into the once too-distant surrounding countryside, now a reasonable commute. The least appealing neighborhoods will be those located in the ring of traditional commuting centers, or “bedroom communities,” outside the city center.

Another way driverless cars will change where people live is by reducing the average cost of transportation for both city dwellers and people living in smaller towns. Research from Columbia University’s Earth Science Institute modeled the cost of transportation if fleets of driverless purpose-built shared vehicles were to be made available in Manhattan, Ann Arbor, and a small town in Florida. Columbia’s research concluded that the combined effect of on-demand autonomous vehicles, lightweight car bodies, and freedom from the overhead costs of car ownership would significantly reduce the cost of personal transportation. The study revealed that Ann Arbor residents would pay 75 percent less, per mile, if they gave up their cars and used fleets of driverless taxis. New Yorkers would enjoy cab rides that cost 50 cents a mile, rather than the estimated $4 a mile for today’s human-driven yellow cabs. Small-town inhabitants could ride around at an estimated cost of 46 cents per mile.²³

Take the pod—meet people

Although conveniences are hard to resist, sometimes life’s inefficiencies can have a positive effect, that they foster social interactions. One side effect of cheap and efficient personal mobility could be loneliness. According to the U.S. Census Bureau, one in four Americans lives alone, and the number of people who report that they’re lonely increases each year. Several theories explain why self-reported loneliness is on the rise, from changes in family structures, to work demands, to the isolating effect of television and the internet, to the false friendships formed on social media.

One reason people feel lonely is that they don’t have a third space, a place that is neither work nor home, but where they go to hang out. In the old days, professors used to enjoy the perks of a faculty club or tearoom, where faculty would meet spontaneously, without a specific agenda, and chat about their research. Outside of work, people used to go to church, a bowling alley, or their local pub. One of the sad realities of modern life is that it doesn’t offer people very many options for third spaces.

In North America, the lives of many middle-class people follow a pattern something like this: After college, by expectation or by necessity, we move to the next phase of life: adulthood. Once we can afford it, we purchase a home with a large, private yard that requires a lengthy and solitary commute to work.

For many people, at the end of a long work day there’s little time left over for spontaneous social activities. Weekends are dedicated to improving the house and yard or catching up on “family time” that could not take place during the busy workweek. Perhaps because of this busy, yet isolated lifestyle, many middle-class professional people don’t have many friends.

Three factors are critical for making friends: physical proximity, repeated unplanned social interactions, and an atmosphere where people can let their guard down.²⁴ Work involves physical proximity and repeated social interactions, but it does not provide a good place to let down one’s guard. That’s why many people have friends from their college years, but not many from later in their lives. The informal camaraderie of college dorm rooms provides physical proximity, repeated exposure, and an environment where people can be themselves.

Like other technologies of convenience, driverless cars will improve the quality of people’s lives by easing the pain of commuting and giving people more options for where to live. Yet, the cost of more convenient transportation will be the loss of another traditional third space, that of public transit. City dwellers of the future could find themselves missing the enforced human contact of the old and inefficient modes of public transportation on subways, buses, and trains.

The other day we saw an ad in the local newspaper that read: “Take the bus—meet people.” What a brilliant way to advertise public transportation! The ad wryly conceded what most people already know, that public transportation is usually not faster or easier than driving. Yet, rather than trying to convince people of what they wouldn’t believe anyway, the ad cleverly focused on another undeniable benefit of taking the bus: the time spent waiting for the bus and rattling around town on inefficient routes will help you make new friends.

Time we “waste” in the car has hidden value. Cars serve as a mobile third space for parents and their children. A recent study of 2,000 parents found that parents spend an average of six hours and forty-three minutes per week chauffeuring their kids to school and to after-school and social activities.²⁵ At that rate, parents and kids wind up experiencing nearly thirty hours every month of enforced togetherness in the car.

As any parent/chauffeur would tell you, much of this driving is sheer drudgery. Many busy parents (ourselves included) would eagerly pop their children into a driverless car and wave them off if such a vehicle were a safe and widely accepted form of transportation. If such a convenience existed, however, its hidden cost would be the loss of precious time in which parents and children mingle on a regular basis. Like the emotional thievery of a smartphone at the dinner table, driverless cars will erase another of the few remaining technology-free zones where we can interact with our children.

I experienced the value of enforced “car time” when I used to drive my then-teenage son to early morning crew practice six days a week. On one hand, I dreaded the 5 am trips, having my deepest sleep rudely interrupted by the alarm clock’s cheerful tune of steel drums. If I had been presented with the option to hand my chauffeuring duties over to a driverless car, I would probably have eagerly embraced it. The driverless car would have been a safer driver than I was and I could have gotten a few extra hours of precious sleep.

In hindsight, the cost of such a convenient solution would have been the loss of the intimacy my son and I enjoyed in those precious early morning car trips. Those trips to crew practice were our chance to spend time together, just the two of us in close physical proximity with no agenda or distractions. As we drove together my son shared his music with me. He shared his thoughts, usually wry analyses of the state of the world. The convenience of a driverless car would have robbed me of memories of the two of us cruising around the banks of the local lake in search of the designated meeting place, embraced by the predawn chill of a hushed and sleeping world.

Friction-free physical mobility could make us lonelier. Or, on the other hand, if going out becomes no more difficult than pressing a button on your cell phone, opportunities for in-person mingling could someday be as easy as mingling online. Another social catalyst will be that driverless cars will be intelligent and data-literate. Passengers could pay a little extra for the “Meet People” option next time they take a driverless pod so they could be matched up with other passengers of the same age, or with similar patterns of web browsing and Facebook “likes.” Someday, when people open up their web browser, they’ll see an advertisement for a driverless pod: “Take a pod. Make a friend.”

2 A Driverless World