Thursday, October 26, 2023

Post 40: A Modern 'Tragedy of the Commons' -- Part 2

 I have a confession.  I am a speed-oholic.  Regardless of whether I am in a hurry to get someplace or not, I almost always drive 5 miles per hour over the speed limit.  I can’t help it, I’m compelled to speed by some inner character flaw.

The thing is, I’m not the only one.  Despite my speeding, I routinely get passed by other apparent speed-oholics who drive even faster than I do!  During rush hour, I would bet that the average speed on many streets is well above the posted speed limit unless congestion forces people to drive more slowly.  In a recent survey, 87 percent of drivers admitted to speeding at least occasionally, although 35 percent say it is never acceptable (hmm . . .). [1]  


According to the National Highway Traffic Safety Administration, speeding was a contributing factor in 29 percent of all crashes that resulted in at least one fatality. [2]  And it is probably safe to assume that speeding contributes to a similar percentage of the 5 million or so accidents that occur each year and the $12 billion that is paid annually in auto insurance payouts.  So if the consequences of speeding are so well documented, why is the problem so pervasive?


Tragedies Galore


In my previous post, I focused on the ‘tragedy’ of congestion that never goes away despite the billions of dollars that are spent annually on road widening and other improvements.  I used the economic theory behind the ‘tragedy of the commons’ and the practical dynamics of Marchetti’s Constant to shed some light on this phenomenon.  In this post, I’m going to detail several other tragedies behind the way we design and utilize our streets and highways.


To start with, let’s get back to the speeding issue because there is more to it than just a character flaw.  We have designed our cities and road networks so that speeding is almost inevitable.  Keep in mind that a large percentage of the population believes in the American Dream – owning a single-family home on a large lot well away from the noise and nuisances of commercial and industrial properties.  In short, our own little slice of Frank Lloyd Wright’s Broadacre City.  




Unfortunately, extending this dream to millions of households means building square mile after square mile of residential subdivisions containing virtually nothing other than single-family homes.  While each home is indeed a quiet refuge from hectic urban life, this layout guarantees that every other aspect of our life requires a trip to a place that is now quite distant from our home.  Sure, some of us might be just a block or two from the supermarket, but for most of us it is a mile or more.  The same is true for our favorite coffee shop, our kids’ school, the dentist’s office, the dry cleaners, and on and on.  A major component of suburban life is now defined by the time we spend in our cars going from place to place.  Since the distances are largely fixed, the only variable in our control is how fast we drive.


No wonder we are tempted to drive 40 (or 45) when the speed limit is 35.  Not only that, but we press our elected officials for street improvements that let us drive even faster.  For decades, we have encouraged our Public Works Departments and civil engineers to make streets straighter, flatter, and wider – ostensibly in the name of accident reduction but mainly so that we feel safe driving faster.  They have added medians, turn lanes, coordinated traffic signals, and better lighting all in the pursuit of traffic safety and capacity.  And yet despite all of these “improvements,” traffic accidents, injuries and fatalities remain stubbornly high.


The problem is closely related to the previously discussed issue of traffic congestion.  Yes, replacing a winding, narrow 2-lane road with a straight, 4-lane divided street will probably reduce side-swipes or cars sliding into the ditch.  But along with that reduction in minor accidents will come a change in the behavior of the people driving that street.  The perceived increase in safety will cause them to drive faster (whether the speed limit is raised or not) and the increase in capacity will cause an increase in traffic volume.  This increase in speed and volume means that the accidents which do occur will now be significantly more severe.  Hence, we haven’t really solved the problem, we have simply changed the nature of the problem (probably for the worse).


Squeezing Out the Alternatives


Our current process of street improvements leads to another problem which is less obvious but equally damaging.  For a variety of reasons that I have covered in previous posts, our cities work better when people have multiple modes of transportation available to them.  Street rights-of-way are perfectly capable of not only accommodating cars, but also people who are walking, biking, taking transit or riding a scooter.  As traffic volumes and speeds increase, however, all of the other forms of transportation become less attractive.  Who wants to walk across six lanes of traffic or bike on a street where cars are zooming past at 45 miles per hour?  It isn’t safe and it isn’t enjoyable.


The result is that in many places, the car is the only viable option for transportation.  Yes, people walk their dogs or ride their bikes for exercise, but they rarely venture out of their subdivisions unless they are on a bike/hike trail that is separate from the street.  Moreover, this type of transportation tragedy is self-reinforcing.  The less common alternative forms of transportation become, the more engineers focus on maximizing vehicular throughput.  Adding pedestrian crosswalks, bike lanes or even bus stops is often seen as a negative because they are viewed as an impediment to smooth traffic flow.


Several years ago, I attended a conference in downtown Dallas.  My hotel was four or five blocks from the location of the conference sessions and while it was not a difficult walk, I noticed that Dallas had a dockless, e-scooter sharing system throughout the downtown.  I downloaded the app and gave it a try.  It was exhilarating and much faster than walking.  But there was a problem.  If I rode on the sidewalk, I scared the bejesus out of pedestrians as I went by – even though I was careful to give them a wide berth.  If I rode in the street, I felt I had to take an entire lane of traffic in order for me to feel safe but then I was a major traffic obstruction.  In short, downtown Dallas was so focused on vehicular traffic that there was no place for a perfectly good form of transportation.


Lipstick on a Pig


When was the last time you heard someone say “Wow, I really like the way the design of this freeway has been integrated into the character of the neighborhood”?  I’m going to guess “Never” because for most traffic engineers aesthetics is so low on their priority list that it rarely is taken seriously.  The fact of the matter is that most urban arterials and highways are a blight that cities must endure rather than an enhancement to a neighborhood’s visual attractiveness.


Another thing you never hear anyone say is “Wow, this is a lovely parking lot, let’s hang out here a little bit longer.”  Although technically not part of the public right-of-way, parking lots are the universal appendage to city streets and most of them are equally ugly.  Our addiction to traveling by car has led to an equal obsession with finding convenient parking – “convenient” meaning obvious in its location and so abundant that empty spaces are always available.  The result is that parking lots are not only visually prominent, but we dedicate a huge percentage of our cities to this unattractive and relatively low-value use.  I checked the percentage of the urban core that is devoted to parking for five midwestern cities (Indianapolis, Kansas City, Minneapolis, Omaha and Wichita) and the average was just over 25 percent. [3]  And this is for the urban core where land values should be highest (suburban commercial areas would be much worse).


This need not be the case.  Some streets are designed to be aesthetically pleasing and to blend nicely with the surrounding area.  My hometown of Kansas City is known for its system of boulevards lined with beautiful trees.  Not that most Kansas Citians would notice since they are more concerned with speeding up to get through that next traffic light (the boulevards are also unnecessarily wide which encourages speeding).  When traffic throughput is your primary concern, the visual quality of the place that the street is passing through is going to be shortchanged.  Hence, this is next in our list of ‘tragedies.’  Instead of our major streets and highways being an attractive gateway to our neighborhoods and business centers, they are an ugly gash which divides instead of unites and which we endure instead of enjoy.


This problem was especially prevalent during the early decades of freeway expansion when limited access highways were extended into the downtown core to meet the needs of suburban commuters.  These roadways were frequently routed through poor neighborhoods which lacked powerful political voices and where land acquisition costs were low.  The result is that neighborhoods that often functioned well (even if the buildings were not pristine) were split in half by six, or eight, or ten lanes of concrete.  The one-two punch of an interstate highway followed by urban renewal projects such as Cabrini-Green in Chicago or Pruitt-Igoe in St Louis destroyed many inner city neighborhoods and fostered decades of social unrest.


Asset or Liability


Finally, there is the economic impact of our current approach to street and highway design.  In theory, a street is a public asset that adds value to all of the abutting property.  This value can be captured by the city through property taxes.  The problem is that this asset comes with an attached liability – the implicit promise by the city to maintain that street or highway forever.  Ideally, that maintenance cost is more than covered by property tax revenue, but that is increasingly not the case.




Our Broadacre City/Futurama approach to urban growth has changed the value proposition of streets.  In short, there is too little value to balance the long-term cost of maintenance.  Look, for example, at the three commercial properties shown above.  Two are older commercial buildings common in the central portions of many cities, while the third is an example of “big box” development common in newer suburban areas.  All three properties include off-street parking, but only the big box example provides a parking lot that is larger than the building itself.  The appraised value per square foot of lot area is $90 for the first example, $58 for the second example, and $17 for the third.  


Thus, the final tragedy is that our sprawling suburban street pattern is generating so little property tax revenue that we are putting our cities in a precarious financial position.  Instead of supporting urban resilience, we are promoting fragility.  Every unexpected event that stresses the municipal budget puts a city at risk of economic failure unless it receives some type of bailout from the state or federal government.  No wonder that some cities seem to careen from one crisis to the next and local tax rates continue to climb.


Solutions


We have allowed the transportation pendulum to swing so far toward the automobile that we have lost the balance that cities and people need.  I like my car and I use it on a regular basis, but I have found that I am healthier, happier and more connected to my community when I occasionally get out of my two-ton, steel bubble.  The focus of our cities should be on the well-being and prosperity of our citizens, and the focus of our transportation system should be on supporting that well-being and prosperity by allowing people to move efficiently.


The modern ‘tragedy of the commons’ is that we have allowed the metric for how we design our streets to be shifted from moving people efficiently in support of their well-being to simply moving vehicles efficiently.  Those two objectives are not at all the same.  The result is a public street system that is often congested, dangerous, ugly and expensive.


Over the next several paragraphs I’m going to suggest several steps that could be taken to swing the transportation pendulum back toward some semblance of balance.  There are, however, two caveats.  First, I’m going to focus on midwestern cities.  The east- and west-coast mega cities have problems that are so different in scale that different approaches are needed.  Second, I’m not at all confident that the solutions I’m going to suggest will ever be implemented widely enough to have much of an effect.  This is odd to write because all of my suggestions are being done now in cities across the country – they just aren’t being done frequently enough to have a significant impact.  The car oriented lifestyle has simply become too ingrained in our American psyche.  We routinely opt for the easy (and often logical) option of the car even if our short-term convenience is, in the aggregate, bad for us and bad for our community. Still, even baby steps move us in the right direction and might someday surprise me with their additive effect.


Shorter trips.  If we can shorten the typical trip length, we would reduce vehicular congestion, increase the usage of alternative forms of transportation, and would probably reduce our inclination to speed.  The first step is to increase the diversity of uses within each neighborhood.  Large swaths of single-purpose land uses, whether they be residential, retail or office, are a bad idea.  The planning profession promoted that approach in the past because it minimized conflicts between adjacent uses, but it has a horrible impact on urban life.


The second step is to increase density in selective areas.  Each metro area should have dozens of moderate-density, mixed use nodes (mini-downtowns, if you will).  People who live in or near each node will have a variety of destinations that they can reach quickly using a variety of transportation options.  The vast majority of people will still live some distance away in low-density residential areas, but even they will have a decent chance of finding what they need in the closest node rather than driving to a singular downtown or a regional shopping center.  Not every trip needs to be short, we just need more trips to be short.


Spread out vehicular demand.  Virtually every midwestern city already has plenty of vehicular capacity, except for selective locations at certain times of the day.  Instead of focusing on increasing capacity (supply), we should spend more time on reducing demand.  The COVID pandemic provided an excellent illustration of this approach because traffic volume in the first few months dropped by 20 to 30 percent and congestion evaporated.  The shift to hybrid work has the potential to extend that reduction in demand and cities should do what they can to encourage employers to adopt that policy.


Even employers that can't do remote or hybrid scheduling can time-shift their work hours by 30 or 60 minutes (or more) to reduce peak hour demand.  Some employers already do this, of course, including some that have different start times for different groups of employees.  This can enable a midwestern company in the central time zone to have some employees work from 7AM to 4PM, and others from 10AM to 7PM thus enabling a human response to customer inquiries from 8AM eastern time to 5PM pacific time.  Although techniques like time shifting and hybrid work will cause managers to have to rethink scheduling and resource allocation, it is not that hard to do with modern technology.  It may be that in-person meetings are concentrated between 10AM and 3PM or on certain days of the week when the majority of people should be in the office.  This might seem problematic at first but could end up being a blessing in disguise for those who dread endless meetings.


Unfortunately, this solution will be of just limited effectiveness for two primary reasons.  First, cities have very little direct control over the hours that people are expected to work.  Cities can suggest and perhaps cajole, but rarely can require changes to work schedules.  Second, a reduction in peak demand that leads to less congestion will simply cause some people to shift their travel habits away from transit or car-pooling to the automobile since travel times are suddenly improved.  This is what happened a few months into the pandemic so that while traffic volumes did decline somewhat, transit volumes declined even more.


Rethink parking.  Our insistence on using cars for nearly every trip we make has led to an almost equivalent obsession with parking.  Not surprisingly, public parking is another classic ‘tragedy of the commons’ type of problem.  Providing free public parking in areas of high demand without any restrictions invariably leads to skewed behavior.  During my career as a city planner, I worked with several cities on revitalizing their historic downtowns.  Parking was always an issue, particularly on-street parking on the primary shopping street.  All of the downtown stakeholders would agree that shop owners and employees should voluntarily park a couple of blocks away so that the best spaces would be available for customers.  Yet when we actually observed parking behavior, a large percentage of the spaces would be occupied for long periods of time by shop owners and their employees.  Everyone wanted someone else to be the one to sacrifice for the common good.

The most common solution to this perceived problem is to provide public off-street parking lots, sometimes at the expense of existing buildings.  This leads to a downward spiral aptly described by Andres Duany (et al) as follows:


. . . at mid-century, with automobile ownership on the rise, a charming old downtown with a wonderful pedestrian realm finds itself in need of more parking spaces.  It tears down a few historic buildings and replaces them with surface parking lots, making the downtown both easier to park in and less pleasant to walk through.  As more people drive, it tears down a few more buildings, with the same result.  Eventually, what remains of the old downtown becomes unpleasant enough to undermine the desire to visit, and the demand for parking is easily satisfied by the supply.  [4] 


In other words, the disease is eliminated by killing the patient.


Planners have attempted to address the shortage of public parking by requiring developers to provide private, off-street parking every time they build a new building.  Unfortunately, the only parameters that planners typically know during the development process are the size of the building and the general use of the building (i.e. retail, office, hotel, etc.).  Despite considerable research on the subject, it turns out that those two factors are poor predictors of parking demand.  Planners pressed on, however, and developed minimum parking standards that are now part of nearly every zoning code.


The fact that building size is a poor predictor of parking demand, and that most parking standards are biased toward meeting peak demand instead of average demand, means that development over the past several decades has been massively oversupplied with parking. [5]  Go to a shopping center or office park on a typical day and you will often find the parking lot only half full.  The problem, of course, is that all of this “free parking” isn’t really free.  The cost of parking is included in the price we pay for every good and service that we buy.  Even people who walk or take the bus to the shopping center pay the same hidden parking fee.  This means that non-drivers (largely poor people) help subsidize the cost of free parking for drivers (largely affluent people).


The oversupply of parking results in retail buildings surrounded by enormous parking lots which means everything is further spread out which, in turn, lengthens every trip that we take.  People often drive to the shopping center to shop at Store A, and then get back in their car to drive across the parking lot to shop at Store B in the same shopping center.  Walking is no longer a viable option.


Cities should consider two significant changes to the way parking is handled.  First, zoning codes should be amended to substantially reduce the amount of off-street parking required by new development.  Some cities have eliminated parking requirements all together which might be a step too far, but major reductions are a good first step.  Second, public parking in areas of high parking demand should always have an explicit cost.  Parking meters and self-pay systems have gotten so sophisticated (including dynamic pricing) and phone-based payment capabilities so ubiquitous that paying for parking isn’t even much of a hassle anymore.  The result will be parking that is easier to find and streets that are less congested.  The icing on the cake is that underutilized parking lots will be converted to much more productive uses which will increase property tax revenues.


Modify street design criteria.  Engineers design streets to meet the criteria given by the community.  In a society dominated by cars, the criteria have been dominated by concerns over traffic capacity and speed.  To swing the pendulum back toward a more balanced transportation system, we need those criteria to include a pleasant pedestrian environment and a safe cycling environment.  Not only is this possible, there is already a movement known as “complete streets” that is gathering momentum across the country.  Traffic lanes are being narrowed and reduced in number, bike lanes are being added, sidewalks are being widened, and crosswalks are being enhanced with bumped-out curbs.  Traffic throughput is still a consideration, it is just not the only consideration.


A Woonerf


While a shift toward “complete streets” design criteria is long overdue, it should be pointed out that not every street need be a biker’s or walker’s paradise.  Some streets should probably retain a focus on moving vehicles as efficiently as possible, but those streets are far fewer in number than most people would expect.  At the other end of the spectrum, cities should consider converting some residential streets to what is known as a Woonerf design which emphasizes pedestrian activity and extensive landscaping over everything else.  Originally a Dutch planning concept, a Woonerf generally has no firm delineation between the sidewalk and the street.  Pedestrians are allowed everywhere, including using the street as a social area for adults or a play area for children.  Cars are allowed but they must defer to pedestrians and speed limits are very low.


Summary


Can we save our streets and highways from the various ‘tragedies’ from which they currently suffer?  I think we should definitely try but I think the odds of success are low.  The ideal that we all secretly covet – being able to jump in our car and drive quickly and easily to any location – is too ingrained for us to give up regardless of how far short reality falls from the ideal.   We have shaped not only our streets but also our cities to try to achieve this utopian dream, only to fail repeatedly.  Perhaps at some point we will realize that the car is not a one-size-fits-all transportation savior – but we aren’t there yet.  I fear the best we can hope for are small victories that point the way toward what is possible if we take the commons back from the automobile.




Notes: 


1. Susan Meyer; “Study: 9 in 10 drivers admit to speeding even though a third say it’s unacceptable”; TheZebra; September, 2023; https://www.thezebra.com/resources/research/speeding-car-insurance-rates/

2. National Highway Traffic Safety Administration; “Risky Driving: Speeding”; 2022; https://www.nhtsa.gov/risky-driving/speeding

3. Parking Reform Network; “Parking Lot Map”; https://parkingreform.org/resources/parking-lot-map/

4. Andres Duany, Elizabeth Plater-Zyberk, Jeff Speck; “Suburban Nation”; North Point Press; 2000.

5. Donald Shoup; “The High Cost of Free Parking”; Planners Press; 2005.


Friday, September 29, 2023

Post 39: A Modern 'Tragedy of the Commons' -- Part 1

 In 1833, English economist William Forster Lloyd wrote an article describing a hypothetical example of human behavior in which the interests of the individual conflict with the interests of society in general.  His example was based on a traditional practice in English villages where a group of local cattle herders shared a common parcel of pasture land on which they were each entitled to let their cows graze.  Lloyd pointed out that it would be in each herder’s best interest to increase the number of cows they had grazing on the common parcel so as to maximize their own economic benefit from the shared resource.  He also pointed out, however, that if every herder utilized the same logical strategy, the common pasture would be over-grazed and potentially destroyed.  Hence, the name “Tragedy of the Commons” that has been applied to this economic concept.

Put more abstractly, when a group of people is given unfettered access to a finite, valuable  resource, they will tend to overuse it to the point where it is damaged or destroyed.  An individual exercising voluntary restraint is not rational – for others would simply supplant them – but the inevitable result is a tragedy for everyone.

The modern “Tragedy of the Commons” that I want to discuss is more complex but the principle is basically the same.  The “commons” for this discussion are the public streets and highways that form the structure of every metropolitan region.  All of us are the group that has been given more-or-less unfettered access to this land so that we can walk, bike or drive ourselves from one place to another.  We also use the public rights-of-way to play catch, hold a neighborhood block party, or stage a community festival – but principally, streets and highways are used for transportation.  The tragedy, of course, is that the more we use streets the more congested they become to the point where their usefulness is damaged (or in the case of gridlock, virtually destroyed).  No single individual has an economic incentive to travel less and the inevitable result is that the combined actions of all of us is traffic congestion that wastes our time and causes us endless frustration.

The Issues


Streets and highways, of course, are not quite the same as a shared pasture because streets are regulated, designed and owned by a governmental entity that has the power to expand or modify the characteristics and capacity of any particular roadway.  There are limits to that power, however, so the ability to expand capacity is roughly finite although many people seem to think that the government’s ability to improve traffic capacity is just a matter of finding more money.


The second problem is that the overuse of a street tends to “destroy” its value for a relatively short period of time.  Yes, the streets in midtown Manhattan might be hopelessly clogged in the afternoon or I-5 in Los Angeles might be reduced to a slow crawl during rush hour, but at other times of the day they can function acceptably well.  Thus, there is the perception that the issue is one of poor timing (“I should have left the office an hour earlier”) rather than a systemic problem that affects the basic operation of the city.  The fact of the matter is that a problem like traffic congestion that reoccurs daily is not a temporary fluke but a serious condition that will ripple through behavioral and design decisions across the community.


Third, our use of public rights-of-way goes well beyond the abstract economic theories of people like William Forster Lloyd.  I am using the Tragedy of the Commons as a framework for discussing the issues, but I am not going to avoid the public health, social equity and aesthetic problems that are equally important.  Remember that more than 40,000 people are killed in traffic accidents every year including more than 7,000 pedestrians and nearly a thousand bicyclists. [1]  There are risks with every aspect of our daily lives, but we need to understand that every transportation choice we make has an impact that cannot easily be reduced to dollars and cents.


Understanding History and the Numbers that Shape It


In 1994, an Italian physicist named Cesare Marchetti theorized that people have historically been willing to spend about an hour traveling to and from work each day (or roughly 30 minutes in each direction).  This travel time budget seems to have been relatively constant for hundreds of years regardless of the transportation technology available.  The result is that cities have been constrained in their size and shaped in their form by the distance that average workers could cover in 30 minutes.  This constraint, commonly referred to as Marchetti’s Constant, is of course an average.  Some workers have shorter commutes and some have longer ones, but the average has been remarkably consistent for major cities for hundreds of years.


Until the Industrial Revolution, pretty much the only way to move through a city was on foot.  Meandering through a crowded medieval city meant that a 30-minute commute would cover perhaps a mile or a mile-and-a-half.  Sure enough, the primary cores of pre-industrial Rome, Paris, London and Beijing (and others) were all two to three miles in diameter.  Cities grew in population by becoming more dense.  And given the lack of modern sanitation systems, more disgusting and disease-ridden.  Aristocrats, of course, could afford to leave the city for their country estates, but the common working man was stuck living in the dismal city.


In 1830, the first steam-powered public railway was opened between Liverpool and Manchester by George Stephenson.  Railroads quickly focused as much on intra-city commuters as on intercity travelers and in 1836 the London and Greenwich railway opened which began a pattern of commuter rail lines radiating out of the heart of London.  The technology spread to other major cities including those in the United States.  Now a half-hour commute might take you 10 or 12 miles, thus enlarging the city considerably.  Steam engines accelerated slowly, however, so they didn’t stop very frequently and the cost of riding them was relatively expensive.  As a result, early commuter trains didn’t extend cities uniformly but created small, affluent villages clustered around each stop every two or three miles.  In Chicago, for example, these would be places like Evanston, Oak Park and Lake Forest.


It would take the invention of modern bicycles and electric streetcars to really begin the first suburban push for the masses.  The “safety bicycle” (as opposed to a high-wheeler) became popular in the late 1880s and 1890s.  For areas that were reasonably flat, a bicycle rider could cover four or five miles in 30 minutes meaning that the diameter of a city could expand to 10 miles.  Electric streetcars, first introduced in Richmond, Virginia in 1888, traveled at similar or slightly faster speeds.  This meant that the area of a streetcar/bicycle city could easily be 10 times greater than a walking city.  By the early 1900s, virtually every major city in the US had a streetcar system fueling suburban development at much lower densities than what was found in the central city.


The capacity and speed of a streetcar, however, paled in comparison with a true rail line.  The problem was fitting a railroad line into a crowded commercial center.  The solution was the subway, first introduced into London in the 1860s but which didn’t become commonplace for several decades.  In cities with relatively straight streets, including many in the US, the elevated train was also a solution.   The spread of subways was initially limited by their complexity and cost of construction.  The shift to electricity spurred their expansion because it eliminated the pollution problems that came with using coal-fired steam engines in an enclosed space.  Gradually, the technology of subway construction improved and systems were expanded and added to more cities.  Elevated trains eventually fell out of favor in most locations because of the noise and fumes, but electric versions remain in some cities.  Subways and trains allowed even longer commutes and the cost eventually fell to the point where working-class commuters could afford them on a regular basis.  In the big cities dense enough to justify subway systems, a 30-minute commute might now be 10 or 12 miles in length and the size of cities expanded accordingly. [2]



Is Marchetti’s Constant still relevant today?  The answer is a definite “yes”.  Using the wonderfully detailed transportation database compiled by Replica (www.replicahq.com), I looked at commute-to-work trips for Chicago, Cleveland and Indianapolis.  Aside from a dip during the pandemic, the average (mean) duration of work trips is remarkably close to 30 minutes (although the median trip duration is a few minutes less).  



The Rise of the Automobile and Expressway


The automobile was initially a novel plaything for the wealthy or for hobbyists who liked to tinker with the latest technology.  In 1908, however, Henry Ford started mass producing the Model T which was affordable enough for the middle class.  In terms of commuting to the central business district of a major city, however, it wasn’t much of an improvement over existing mass transit options.  Streets made for pedestrians, wagons and carriages were simply too crowded for cars to move quickly.  The potential for expanding personal mobility was there for all to see, however, it just needed the right visionary and the appropriate infrastructure.


One such visionary was Frank Lloyd Wright who in the early 1930s publicized his concept for maximizing the personal mobility offered by the automobile in his theoretical model of suburban development known as “Broadacre City.”  He envisioned each family living in a single-family home on at least one acre of land with only limited areas of dense development.  His ideas, which included extensive writings on the democratic nature of an ideal society, were widely discussed but never came to fruition. [3]  The concept that families could escape the problems of the city, live on a tract of land large enough to raise much of their own food, and travel freely with their own automobile captured the imagination of people mired in the depths of the Great Depression.


Just a few years later at the 1939 World’s Fair in New York, General Motors presented an even more ambitious view of the future in an exhibit entitled Futurama.  Created by industrial designer Norman Bel Geddes, the exhibit was a scale-model rendering of urban life in 1960 that featured high-rise commercial buildings and vast suburban communities full of single-family homes, all connected by multi-lane, multi-level expressways that promised nearly uninterrupted traffic flow.  During its nearly two-year run, the exhibit had nearly 30 million visitors who sat in one of 552 chairs on a conveyor system that moved them past detailed dioramas showing a Utopian version of the future while a narrator explained how wonderful life would be. [4]  For a country emerging from the depression and dreading the possibility of a world war, it was an affirmation of the power of technology to solve society’s problems.


A diorama from the Futurama exhibit at the 1939 World's Fair


The exhibit was funded by General Motors, of course, because it was largely an advertisement for how amazing life could be if everyone owned a car (or two).  It was a compelling vision, however, and one that turned out to be remarkably prescient.  After World War II, servicemen returned to a country that was now a world power.  They were in search of housing, jobs and a better life, and concepts like Broadacre City and Futurama provided the blueprint for how it should work.  Expressways came to life via the federally funded interstate highway system and suburbia took shape through mass-produced housing in places like Levittown outside of New York City.  Households steadily became more affluent, automobiles provided increased mobility options, and every level of government spent mightily to build streets and highways to make it all work.  

New suburban communities sprang up outside every major city full of new subdivisions, new shopping centers, new schools and new streets.  If you couldn’t afford a home in a particular city, simply commute a little further out and the price would drop.  Strict zoning regulations (and often racially biased deed restrictions) made suburban locations seem free from the chaos of big city life.  If it wasn’t exactly what Broadacre City and Futurama had promised, it was at least reasonably close.  What could possibly go wrong?


The ‘Tragedy’ of Induced Demand


Here is where we loop back to our friend William Forster Lloyd and his economic theory about the unfettered use of a finite resource.  The entire suburban experiment depends upon a system of streets and highways that can provide free-flowing traffic to a rapidly growing volume of vehicles traveling to and from work, and dozens of other destinations.  Initially, it all works reasonably well, but as communities become fully built out the streets get congested and citizens start demanding road improvements.  Two-lane streets get widened to four lanes and then six lanes.  Highways get rebuilt as expressways with grade separated interchanges, multiple lanes and sometimes multiple levels.  With each improvement project promises are made about eliminating congestion and reducing traffic delays, and yet congestion always returns within a few years, often worse than before.


Welcome to what transportation planners now refer to as “induced demand.”  When road improvement projects are designed, they are based on careful projections of future demand based on past trends.  What is generally ignored (at least until recently) is that road improvements change human behavior which means that past trends are no longer valid.  For example:

  • People who avoided a particular roadway because of congestion will now use that road because of the improvements;

  • People who drove during non-peak hours because of congestion will now drive during peak hours (or whenever is most convenient);

  • People who avoided congestion by either not traveling or by using mass transit will now switch to driving on the improved road; and 

  • Developers who had avoided an area because of congestion will now build new projects that increase demand beyond previous projections.

In short, demand appears to blossom out of nowhere and road improvements that were supposed to be effective for a decade or more are clogged within a few short years.


This is the “unfettered access to a finite, valuable resource” in automotive form.  Everyone is acting rationally and yet the result is inevitably failure.  It is true, of course, that a road which has been expanded can be expanded yet again,  But eventually, a limit is reached.  


The Katy Freeway (Interstate 10) in Houston is an interesting case study.  In 2004, the American Highway Users Alliance (AHUA) called one of the interchanges on the Katy Freeway the 2nd worst bottleneck in the country, supposedly wasting 25 million hours of commuter time each year.  In response, the state of Texas spent $2.8 billion to widen 12 miles of the freeway – up to 23 lanes at certain points!  Initially, traffic congestion did decline significantly and the AHUA called the project a “success story.”  Unfortunately, in the years that followed things got considerably worse, with travel times increasing 30 to 50 percent in just 4 years. [5]  According to Google Maps, a 30-mile drive from downtown Houston to suburban Pin Oak Village which takes 32 minutes in free-flowing traffic takes over an hour during the afternoon peak.  Capacity has increased, but delay and congestion have gotten worse despite the enormous investment.


Summary – Part 1


It seems that nearly everyone likes to complain about traffic congestion, even in cities where traffic during much of the day is relatively light.  As a result, traffic improvement projects are popular and we spend over $120 billion on highway and street construction each year – up from $60 billion just 20 years ago. [6]  Arguably, however, we are not getting much bang for our buck.  The fact of the matter is that expanding capacity rarely solves the problem of traffic congestion for more than a year or two. 


The largest metropolitan areas are the closest to reaching the “finite” part of William Forster Lloyd’s definition which means that they tend to have the most congestion.  Lists of the most congested cities in the U.S. typically have Chicago, Boston, New York City, Philadelphia and Miami at the top followed closely by Los Angeles, San Francisco, Washington, Houston and Atlanta. [7]  At times, these cities are nearly dysfunctional from a traffic perspective and there are relatively few affordable solutions left to implement from a traffic capacity point-of-view.


What is worse, however, is that traffic congestion is not the only – and perhaps not even the most important –  part of the “tragedy of the commons” that I want to discuss.  Check back in a couple of weeks for the rest of the story in Part 2 of this post, including some suggestions for what cities should do instead of widening more streets.





Notes:


1. National Traffic and Highway Safety Administration; “Early Estimates of Motor Vehicle Traffic Fatalities and Fatality Rate by Sub-Categories in 2021; U.S. Department of Transportation; May 2022; https://crashstats.nhtsa.dot.gov/Api/Public/ViewPublication/813298

2. Jonathan English; “The Commuting Principle that Shaped Urban History”; Bloomberg CityLab; August 2019; https://www.bloomberg.com/news/features/2019-08-29/the-commuting-principle-that-shaped-urban-history

3.  Frank Lloyd Wright Foundation; “Revisiting Frank Lloyd Wright’s Vision for ‘Broadacre City’ “; September 2017; https://franklloydwright.org/revisiting-frank-lloyd-wrights-vision-broadacre-city/

4.  Alex Davies; “The World’s Fair Future of 1939 and the Quest for Our Next Utopia”; Wired; December 2017; https://www.wired.com/story/worlds-fair-1939-futurama-utopia/

5.  Joe Cortright; “Reducing Congestion:  Katy Didn’t”; City Observatory; December, 2015; https://cityobservatory.org/reducing-congestion-katy-didnt/

6.  Federal Reserve Bank of St. Louis; “Total Construction Spending:  Highway and Street in the United States”; July, 2023; https://fred.stlouisfed.org/series/TLHWYCONS

7.  Chris Gilligan; “The 10 U.S. Cities with the Worst Traffic”; U.S. News and World Report; May 2023; https://www.usnews.com/news/cities/articles/10-cities-with-the-worst-traffic-in-the-us