Realtor.com has been serving up homes to prospective buyers for nearly thirty years. If you go to the site and search for recently built homes in Sacramento, Phoenix, Charlotte, Dallas, or almost any place of your choosing, search results will consist of single-family houses with an attached, two-car garage. Local governments across the country generally abide by the rule of perpetual urban sprawl.
These search results aren’t any different from what they were before I completed my urban planning degree more than twenty years ago. And results will likely look much the same in another twenty years. There are two variants of urban sprawl. One is horizontal. The other is vertical. Horizontal sprawl is synonymous with suburbia. Vertical sprawl refers to the high-rise residential towers that block the sun, create wind tunnels, and contribute disproportionately to CO2 emissions. In this article, I’m focusing on horizontal (suburban) sprawl.
The Rule of Perpetual Urban Sprawl as Evidenced by Walk Score
Houses in the 120-year-old neighborhood in which we raised our children have walk scores in the “very walkable” range of 80-90. Houses on some streets have higher scores between 90-100, which is in the “walker’s paradise” range. In contrast, new single-family houses listed on realtor.com typically have scores in the “car-dependent” range of 0-49.
I’d like to say just a few words about walk scores in case you’re unfamiliar with what they are. The Walk Score algorithm considers aspects of urban form, such as street connectivity, block length, and distances to amenities. Scores range from 0 (car dependent) to 100 (walker’s paradise). The algorithm has limitations that I won’t get into here and sometimes their data sets are incomplete, but it’s the best publicly available measurement of walkability we have. You can visit walkscore.com, punch in your address, and see your score.
Each new listing on realtor.com with its attendant low walk score is the product of a series of decisions made by local politicians, developers, and municipal planners. It’s been my experience that relatively few people who operate in one of these three roles have any interest in creating the human-scale environment of the sort that Halifax’s city builders constructed between 1900 and 1920.
Below, are new homes in Atlanta listed on realtor.com, which shows one of thousands of examples illustrating how the rule of perpetual urban sprawl plays out in practice.

While employed as a municipal planner in both the U.S. and Canada, I worked in bureaucracies wedded to the idea of continuously expanding suburbia. Few people I interacted with thought much about the long list of issues born of auto-dependency or the need to change the way we engage the public and build communities.
Over the past three decades, many have written about the pathologies associated with urban sprawl. Step into most municipal planning offices, however, and these problems rarely carry much weight, and the status quo—established in the late 1940s —reigns supreme. I found the disconnect between the culture of the planning office and the problems the profession was central to creating to be a disturbing experience.
The problem was that I deeply value being able to walk to everything I need or want in a week, and you can’t do this in suburbia. Related pathologies include CO2 emissions, disinvestment in older communities, steadily increasing traffic congestion, poor aesthetics, overcrowded or underutilized schools, strained infrastructure, rising taxes driven by infrastructure costs, social isolation, poor health outcomes, and a significant loss of open space, forests, wetlands, farmland, and other natural assets in communities of all sizes.
My experience in planning offices, combined with the listings on realtor.com, suggests that the production of bad human habitat will remain the norm in America, endlessly pursuing development that fractures us socially, harms our health, and is disastrous for us environmentally. Constructing communities around the automobile rather than the human being may go down in history as one of the biggest tragedies mankind ever produced.
I want nothing more than my prediction regarding perpetual urban sprawl to be proven wrong. This would, however, require a shift on the part of mainstream developers, local politicians, and municipal planners. Over the past twenty years, the rhetoric has shifted somewhat, but aside from a handful of exceptions, results on the ground are largely the same.
Here, I am excluding older, pre-WWII suburbs that are already built out. If you’re familiar with present-day development practices, you know there are a handful of affluent pre-war “urban suburbs” and small cities that have produced excellent human-scale re-development in recent decades. Boulder, CO; Alexandria, VA, Rockville, MD; the Green Lake section of Seattle, and Stewart, FL are all examples of municipalities where planning and design practices produce favorable outcomes. These municipalities fall within America’s bubbles of affluence, where education levels and expectations are high relative to the rest of the country.
An Exception to the Rule of Perpetual Urban Sprawl
I’m aware of only a handful of conventional, post-WWII suburban municipalities in the United States that serve as an exception to the rule of perpetual urban sprawl. Gaithersburg, MD, is the most relevant example because it embraced human-scale development patterns over thirty years ago. The two municipalities in which I’ve worked as an urban planner represent the rule.
A brief comparison of what’s happened in Gaithersburg with where I’ve worked highlights the gap between municipal rhetoric and reality regarding the commonly used phrase “fighting sprawl.” Wanting to avoid engaging in hyperbole, I’ll support my points by comparing the walk scores for recent development in Gaithersburg with development where I’ve worked.
In 1990, I happened to have lived in Gaithersburg for a few months. At the time it was a partially built out, nondescript, nine-square-mile, suburban municipality 15 miles north of Washington DC.1 It’s bisected by both a state and federal highway. The address of the townhouse where I lived at 860 Baybridge Drive has a low walk score of 36.
Aside from a small, tired-looking historic center, everything around me at the time was conventional suburbia, indistinguishable from a thousand other places. I had no reason to assume Gaithersburg’s future would look different. Yet, when working on my masters thesis a decade later, Maryland state planners pointed me toward Gaithersburg after I asked what they knew about municipalities that were successfully overcoming barriers to building human-scale development.
Seeds of change came in the form of a collaboration in the late 1980s between a developer, two urban designers, and a mayor who shared a vision. Working with planning staff, they built Kentlands, a large pedestrian-oriented mixed-use neighborhood of a sort the FHA effectively banned in the 1930s.
In the mid-1990s, a second developer stepped forward and built a comparable neighborhood called Lakelands adjacent to Kentlands. By the late-1990s, Gaithersburg had itself the makings of a sizeable human-scale town covering some 700 acres that would become home to over 6,000 people.
The mix includes single-family homes targeting different price points, apartments, condos, an elementary school, a middle school, parks, and a large commercial component. Results met high expectations, the caveat being that the developer had to build most of the commercial piece (shared by the two neighborhoods) along conventional suburban lines because of an economic downturn.
Today, that same commercial component is being redeveloped as a mixed-use project called Kentlands Market Square, in line with the original vision of creating an extensive environment in which the simple act of walking to a variety of destinations is an engaging, pleasant human experience.
Walk scores for Kentlands and Lakelands are 84 and 71 respectively and fall within the “very walkable” range, which is a world apart from the Gaithersburg built out over the previous forty years.
After building Kentlands and Lakelands, approximately 30% of the municipality consisted of previously undeveloped land. And how they chose to develop this land (and land they later annexed) is what makes Gaithersburg an exception. They could have reverted to auto-dependent development, but they didn’t. Most (but not all) projects completed since the late 1990s are mixed-use and produce high walk scores that stand up to scrutiny.
Spectrum Town Center (231 Spectrum Ave.) is a mix of apartments, shops, and restaurants. Its walk score is 72 (“very walkable”). Downtown Crown (135 Crown Park Ave.) covers 180 acres and features four distinct neighborhoods and a sizable downtown. Its walk score is 80 (“very walkable”). Watkins Mill Town Center occupies 130 acres. When complete, it will include 1100 residential units of various types and 1.2 million square feet of retail and office space. Walk scores for homes here will also fall within the “very walkable” range.2 Importantly, Gaithersburg’s larger projects include a mix of single-family homes, townhouses, condos, and apartments.

In October 2022, I traveled to Gaithersburg to see this newer development for myself. Kentlands, which I visited years earlier, had aged well. Newer projects generally followed best practices for creating places that prioritize pedestrians over cars. Garages are usually placed behind houses. Streets are narrowed. Street trees are planted at regular intervals to provide a canopy. Quality exterior building materials are the norm. Buildings are located close to the street and heights range from two to six stories. Projects feature both a mixture of uses and housing types. In sum, Gaithersburg sets out to create a public realm that is an inviting, interesting human experience that compels you to walk places. Gaithersburg does not do these things 100% of the time, but they generally get things right, and the municipality has been doing this for over thirty years.
Walk scores produced by development in the two municipalities in which I’ve worked reflect the status quo and contradict municipal claims regarding the pursuit of “sustainability.” A sample of fifty newly built houses in Baltimore County listed on realtor.com in January 2023 produced an average walk score of 18 (“car-dependent”). A fifty-house sample within the Halifax Regional Municipality (i.e., outside the city proper) produced a stunningly low average walk score of 8.5. In both municipalities, single-use residential development reigns supreme, and future development will not increase these scores.
I include Halifax scores for a reason. I worked in their planning department between my first and second year of graduate school and have observed Canadian planning practices up close for years. They are a more bureaucratic, less accountable variant of U.S. planning practices.3
Canadian municipalities build less attractive suburban pods that have slightly higher residential densities. In recent years, Canadians have also started building mid and high-rise residential buildings in random locations in suburban settings as well. As a result, outcomes regarding auto dependency are worse than the Americans to which Canadians often compare themselves favorably. Although Canada has just 11% of the U.S. population, it has eight metro regions that are more congested than the worst American metro area (NYC). Toronto is now the third most congested city in the world because of ill-conceived urban planning practices.4
In singling out Gaithersburg as an exception to the rule of perpetual urban sprawl, I’m considering the thousands of municipalities across America that still have undeveloped land on which to either pursue auto-dependent or human-scale development. More recently, a handful of other municipalities such as Dublin, OH, Gaithersburg, MD, and Tigard, OR have joined what I hope is a growing list of local governments pursuing what amounts to a quality-of-life agenda instead of a growth management agenda.
What makes Gaithersburg stand out, again, is that 30 years ago is that they had been a suburban municipality indistinguishable from thousands of others across the country before making a conscious decision to stop building auto-dependent development and start building at the human scale. In a nation of over 330 million people, there just aren’t that many municipalities that have moved from auto-dependent to human-scale development patterns.
It’s helpful to understand Gaithersburg’s accomplishments in context. At the time they embarked on change in the late 1980s, over half of their buildable land was already built out along suburban lines. And longstanding redevelopment plans along their principal commercial corridor (MD State Highway 355) have gone slowly. On the whole, Gaithersburg is not an urban environment of the sort in which we raised our children. Regardless, they’ve taken almost every opportunity over the past three decades to move in that direction. And there are now large swaths of the municipality that are eminently walkable.
It’s no accident that in 2022, Fortune deemed Gaithersburg the 7th best place in America for families, reflecting, in part, that it operates as an exception to the rule of perpetual urban sprawl.
The question is why was Gaithersburg successful in moving from auto-dependent development to pedestrian-oriented human-scale development when so many other jurisdictions remain mired in rhetoric? From a policy and procedural perspective, what did they do differently? I answer these questions in a follow-up article titled Four Achievements Required to Break the Rule of Perpetual Urban Sprawl.
- Gaithersburg’s size in 1990 is noted in Gaithersburg’s 1997 Master Plan Process Overview. See https://www.gaithersburgmd.gov/services/planning-services/city-master-plan. ↩︎
- Rogers Consulting did both the up front design charrette and the overall project design for Watkins Mill. See: https://www.rodgers.com/projects/#project-662; Gaithersburg has also provided additional background information. See: https://www.gaithersburgmd.gov/government/projects-in-the-city/watkins-mill-town-center. ↩︎
- In 1934, Congress passed the National Housing Act which ushered in the FHA’s car-centric standards. In 1935, the Canadian Parliament passed the Dominion Housing Act, which was based on the National Housing Act. See, J. David Hulchanski, “The 1935 Dominion Housing Act: Setting the Stage for a Permanent Federal Presence in Canada’s Housing Sector.” Urban History Review, 1986, 15 (1): 19–39. https://www.jstor.org/stable/43559633. ↩︎
- Jamie Casemore, “Toronto ranked third worst in the world for time stuck in traffic,” National Post, January 2024, https://nationalpost.com/news/toronto-ranked-third-worst-in-the-world-for-time-stuck-in-traffic; For comparison of Canada with USA see: “Canada Traffic,” TomTom, 2023, https://www.tomtom.com/traffic-index/canada-country-traffic/; “United States of America Traffic,” TomTom, 2023, https://www.tomtom.com/traffic-index/united-states-of-america-country-traffic/. ↩︎