The American built environment encourages driving (and frustrating traffic jams), and driving should be an option, but are there ways to change our cities so we can have the choice to drive less and walk more?
San Diego traffic
Photo by F. Kaid Benfield
The way our cities and suburbs are structured hampers healthy lifestyles. In People Habitat: 25 Ways to Think About Greener, Healthier Cities (People Habitat Communications, 2014), F. Kaid Benfield outlines aspects of our current environment, infrastructure and culture that we can change to encourage healthier and greener living, while pointing out discrepancies to pay attention to, from the cathartic overuse of “green” to gloss over environmentally destructive products or places to foster walkability. The following excerpt is from Chapter 16, “Driving Should Be an Option.”
Americans’ high driving rates contribute mightily to economic waste and environmental degradation. Yet we have built a country in which most people have few alternatives. What can we do in our built environment to turn things around? Fortunately, research provides some clear answers.
I like cars and I like driving. Those who know me well know I’m telling the truth and, if you’re looking for a purist manifesto, you’ve found the wrong book. In fact, maybe it’s my 1960s North Carolina upbringing, but I like nice cars and have always managed to have one, thank you very much.
What I would not like, though, is being dependent on a car for every single thing I need or want to do. I also like public transit when it’s working well—I’ve literally met some of my best friends while on public transportation—and I frequently use it for commuting. I love walking places, especially city places, and generally manage my daily chores other than commuting on foot. And I’m passionate about bicycling, too, though I ride for fitness, not everyday transportation. I guess you could say that I’m a multi-modal kind of guy, and I feel lucky that my living conditions allow me to practice a life of transportation-by-choice.
I know most Americans aren’t so fortunate. Ours is an overwhelmingly auto-oriented landscape, except in a few big city downtowns and older neighborhoods, many populated mostly by residents without kids. Most people have to drive to get to work or school, to go out to eat, to take their laundry and dry cleaning for service, to shop for groceries. If they have children, chances are they are also spending a lot of time shuttling the kids around from one event to another. It’s normal, I think, by today’s standards. But it’s not much fun.
I’m old enough to remember when driving was fun. If you can tell a lot about a society’s culture from its popular music lyrics, the 1960s were surely the golden age of the American automobile. On July 4, 1964, a new single became the first number one song by that most American of bands, the Beach Boys. Performed with a driving beat and Brian Wilson’s soaring harmonies, “I Get Around” celebrated the unequivocal freedom and exuberance that cars provided, particularly on the group’s home turf of southern California:
We always take my car ‘cause it’s never been beat
And we’ve never missed yet with the girls we meet…
I get around
Get around, round, round, I get around
From town to town…
Readers of a certain age may also recall that other hit songs of the 1960s included such paeans to the automobile as “GTO” (Ronny and the Daytonas), “Mustang Sally” (Wilson Pickett), and several more by the Beach Boys, including “Little Deuce Coupe” and “Fun, Fun, Fun.” Prince kept up a smidgen of momentum with “Little Red Corvette” as late as 1983.
By the turn of the twenty-first century, though, exuberant car songs were confined to oldies radio stations. If cars show up in lyrics today, chances are that the song is something darker and considerably less innocent than those popular fifty years ago. One can speculate on the reasons, but surely one of the most compelling is that it has been quite a while since driving was “fun, fun, fun” for most Americans.
Instead, driving has become simply a matter of getting from point A to point B, and far too often doing so hampered by traffic congestion and stress, to say nothing of the havoc wreaked on our natural environment. Instead of the open convertibles that symbolized the most desirable cars of the 1960s, sport utility vehicles—essentially complete family rooms (if not fortresses) on wheels that isolate their passengers as much as possible from the external world—became the preferred vehicles of the 1990s and early 2000s.
What happened between the golden age of the automobile and today? Just as cars made it possible to expand our communities far beyond traditional downtowns and rail corridors, the act of spreading out—suburban sprawl—placed increasing distances between the various places where Americans live, work, shop, go to school, and worship. The increased distances inevitably led to a tremendous increase in driving: the number of miles driven annually by passenger cars in the US has tripled since the 1960s, reaching a peak of just over three trillion in 2007. While the dramatic growth in driving has begun to slow and even reverse in recent years (in part because of the financial crisis and recession that hit the country beginning in 2008), we still have a long way to go before approaching anything near sustainability.
As a result, traffic congestion has become an everyday menace of American life. According to researchers at Texas A&M University, as of 2011 congestion was draining $121 billion annually from the US economy in the form of 5.5 billion lost hours of productivity—equivalent to 137 million weeks of work or vacation time—and 2.9 billion gallons of wasted gasoline and diesel fuel.
With two-thirds of oil use in the US going to transportation, the average American now uses over twice as much oil as the average person in other industrialized nations, and over five times as much as the average person in the world as a whole. As a result, carbon dioxide emissions from driving in the US remain some 35 percent higher today than they were even as recently as 1990. The US continues to lead the world in per capita carbon emissions, emitting about twice as much of the potent greenhouse gas per person as Germany, the United Kingdom, or Japan, and about three times as much as France.
Given these sobering facts, the challenge in creating sustainable people habitat is to maximize convenience and livability for the community’s residents, workers, and visitors while minimizing the burdens on the environment created by the basic need simply to, as the Beach Boys put it, get around. The task is an especially important one, given the relative importance of transportation to energy consumption and corresponding greenhouse gas emissions. A 2007 study reported in Environmental Building News demonstrated that the amount of energy used (and greenhouse gases emitted) by a typical office building’s operation is dwarfed by the amount that employees and visitors typically consume getting there and back.
To me, the most interesting aspect of Americans’ overwhelming dependence on driving is that people’s driving habits are not distributed evenly. With the wonderful world of GIS (geographic information systems) mapping, you can see a geographic representation of miles driven per household: those of us in outer suburbs drive a lot more than those of us in more urban locations, whether the latter are in city centers or in the hearts of older towns and suburbs.
Let’s look a little closer at the reasons for the variations. In 2010, transportation uber-researchers Reid Ewing (University of Utah) and Robert Cervero (UC-Berkeley) published a painstaking “meta-analysis” of nearly 50 published studies on the subject of land use and travel behavior. Writing in the Journal of the American Planning Association, the two returned to a subject to which they have dedicated most of their careers, in this case updating their previous meta-analysis from 2001.
What they found: When it comes to land use, driving, and the environment, location matters most. The study’s key conclusion is that how close a household is to common trip destinations is by far the most important land use factor in determining a household or person’s amount of driving. Such “destination accessibility” almost always favors central locations within a region; the closer a house, neighborhood, or office is to downtown, the shorter the average distance one has to drive to other places and the lower one’s rate of driving. The authors found that central locations can be almost as significant in reducing driving rates as other significant factors (e.g., neighborhood density, mixed land use, street design) combined.
The clear implication is that, to enable lifestyles with reduced driving, oil consumption, and associated emissions, environmentalists should continue to stress opportunities for revitalization and redevelopment in centrally located neighborhoods. As Ewing and Cervero put it: “Almost any development in a central location is likely to generate less automobile travel than the best-designed, compact, mixed-use development in a remote location.”
The authors carefully examined each study, applying statistical analysis to tease out which land use characteristics had the biggest impacts on travel behavior when extraneous factors such as income were controlled. After discussing destination accessibility, the authors continue:
“Equally strongly related to [vehicle miles traveled] is the inverse of the distance to downtown. This variable is a proxy for many [other factors], as living in the city core typically means higher densities in mixed-use settings with good regional accessibility. Next most strongly associated with VMT are the design metrics intersection density and street connectivity. This is surprising, given the emphasis in the qualitative literature on density and diversity, and the relatively limited attention paid to [neighborhood street] design. The weighted average elasticities of these two street network variables are identical. Both short blocks and many interconnections apparently shorten travel distances to about the same extent.”
In addition to the effect on rates of driving, Ewing and Cervero also found that, among the characteristics studied, street networks with a high rate of intersections and street connections per square mile are the most strongly correlated with high rates of walking. This makes sense, because a high degree of street connectivity creates alternate routes to destinations, in many cases offering walking distances that are shorter and more direct. Distance to a store was the second most influential factor in influencing walking, with the location and the accessibility of transit next. (Most transit trips begin and end with walking.)
Interestingly, neighborhood density, when separated from the other factors, was found to be less significant than other characteristics in influencing both miles traveled and vehicle trips, although still influential. On its face, this would seem to contradict a substantial body of literature that associates increasing density with reduced driving. Ewing and Cervero suggest that perhaps measures of density are inadvertently acting as proxies for other significant factors (“i.e., dense settings commonly have mixed uses, short blocks, and central locations, all of which shorten trips and encourage walking”).
Ewing and Cervero spend a good deal of space attempting to address the issue of “self-selection” or whether, to give an example, people walk more in places with a good walking environment because they are predisposed to walk and choose to live there, rather than because the environment entices them to walk. Reid Ewing explained this to me at some length over the phone a few years back, and I understand it, but I’m not entirely sure it matters. All indications in the market suggest that we have a large, growing, unmet demand for close-in, walkable neighborhoods and an emerging surplus of automobile-dependent environments.
Unless that unmet demand for close-in, walkable environments somehow turns into a surplus, which isn’t happening anytime soon, building more of them will reduce driving and increase walking. The environment doesn’t care about psychological motive. In any event, the authors found in this case that applying research controls for self-selection might, if anything, show an even more significant influence of land use on behavior.
The best news is that Ewing and Cervero have found that the effects of the various individual factors studied—location, transit, connectivity, land use mix, and design—are additive in reducing driving and increasing walking. If a municipality or developer is able to take advantage of (or strengthen) all of them, the result will be a more sustainable development than if some are missing. What Ewing and Cervero (and all the researchers whose studies they analyzed) have given us is a science to go with the art of better placemaking.
So, what about people such as myself, who enjoy driving sometimes when it’s a matter of choice? Can we as a society get back to the optimistic, exuberant feelings of driving in the early 1960s? Maybe not: we have done some damage to the planet since then, and these are more sobering times for other reasons, too. If we can reclaim exuberance, it is unlikely to be because of cars and driving. But we can start down the road, so to speak, and being more thoughtful about our built environment can help.
Our goal should be to create more driving-optional neighborhoods. Achieving it will be harder to accomplish in suburbs and smaller towns than in cities, but even in less accessible locations we can still plan and design our communities more thoughtfully to encourage walking and shorter driving distances, and make a difference. Given the massive increases in population expected for the US and elsewhere over the next half-century, we had better.
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