Is Density Your Destiny?

Finding tomorrow’s favored cities with today’s data

Karl Sluis
12 min readDec 5, 2018

The year is 2038. President Ocasio-Cortez is two years into her first term. Hurricanes regularly strafe the Eastern Seaboard while fires and droughts ravage the West. You’re ready to move somewhere safe and new, one of those popular cities that everyone’s moving to: Joliet, Newburgh, Eugene, or maybe even Iowa City. Cleveland was at the top of your list — everyone’s moving to Cleveland, after all — but… it’s just too popular.

Cleveland, Ohio — hey, it could happen!

It may sound implausible — and no, I’m not talking about a bartender becoming President of the United States — but someday, you might be moving to an unfamiliar city with one important asset: density, a trait shared by all the cities named above.

It is a truism of urban design that density is destiny. As City Lab writes,

Density — the close clustering of people together in communities — is a big factor in the technological and economic progress of cities and nations. Economists, urbanists, and place makers have found density to be associated with everything from greater energy efficiency to higher levels of skilled and talented people, higher rates of innovation, and higher income.

while density’s foil, sprawl,

…correlates with higher rates of obesity, traffic fatalities, ozone pollution, and lack of social capital.

Increasing density directly addresses three of the biggest challenges we face as a society in the twenty-first century: adequate housing, sufficient transportation, and climate change. The costs of sprawl are simply too great for this planet to bear, and arguably, too great for our culture, as well. Density encourages cultural collisions, competition, collaboration, and innovation. Without density, we’re doomed; with it, we just might make it.

Adding density to a city should be a straightforward affair: simply build more, taller buildings near the city’s core. Unfortunately, there are many forces aligned against creating more density, such as zoning laws, cultural expectations and selfish landowners. Given this resistance, why not take a look at cities large and small, across the country, that already have a sufficient amount of population density? It’s my belief that these cities are best positioned to grow and thrive in the future. These cities already have the infrastructure, housing, and citizens that are ready to support greater density. It’s often better to play to your strengths, after all.

Likely, when you think of a city that has population density, you think of the city, New York City. Let me tell you, you’re not wrong.

New York City is the Michael Jordan of population density. Together, the city’s five boroughs have a population density of 27,000 people per square mile — about 1,000 square feet for every person — and that’s an average figure. Some parts of Manhattan exceed 100,000 people per square mile. Take a look: any dot represents a part of the city where density exceeds 10,000 people per square mile, and any orange colored dot on the map below represents density over 20,000 people per square mile.

It’s fair to argue that parts of New York are too dense — good fences make good neighbors, after all. To find cities that have enough density, I’ve arbitrarily selected 10,000 people per square mile as my baseline. This figure includes the whole area of cities like San Francisco, Boston, Chicago, Philadelphia, and Miami, as well as pockets and neighborhoods in other cities across the country. Check out this map of all Census tracts in the U.S. with more than 10,000 people per square mile, density from sea-to-shining-sea:

Fitting 10,000 people into a square mile isn’t that hard — it leaves almost 3,000 square feet, or the area of a fairly large house, for each individual person. This level of density creates the sort of close-knit, walkable, charming communities that so many of us covet. 42.6 million Americans — over 13% of the country — live in one of these communities. I looked at every one to discover some patterns in these places; generally, these communities fall into four buckets:

  • Major Cities like New York, New York
  • Secondary Cities like New Orleans, Louisiana
  • Old Cities like Erie, Pennsylvania
  • and College Towns like Ann Arbor, Michigan

Let’s explore these cities, these dense cities with bright destinies.

Major Cities

I was surprised to discover density in the nation’s second-largest city, the ultimate icon of sprawling development, of the suburban lifestyle, and of the hellish highway commute. Presenting: dense Los Angeles.

In the above map (and all following), every dot marks an area where population density exceeds 10,000 people per square mile. Los Angeles has this level of density in droves: Santa Monica, Long Beach, and Downtown L.A. are positively saturated. Even areas farther out, in the North Hills, in Santa Ana, even in the Inland Empire, have pockets of density.

Los Angeles may be well-positioned for the future. Its fair weather makes alternative transportation options, like biking and scooting, possible and pleasant year round. The city’s housing stock mostly consists of single-family housing so there’s room to build up and add room for more people. It’s only a bit of a stretch to imagine Los Angelinos abandoning their cars, constructing more apartment buildings, and creating a denser, more sustainable, more livable city for themselves.

Although I already covered New York City, let’s zoom out and see all the beautiful density in the New York region as a whole. As I mentioned, all five boroughs of New York are exceptionally dense, yet I was surprised to see that Jersey City and Hoboken, just across the Hudson River from Manhattan, are just as dense! Check out all the other density in the region: Yonkers and White Plains in New York, Stamford in Connecticut, Patterson, Spring Valley, Newark, Elizabeth, and New Brunswick in New Jersey. There’s even some density an hour north of the city, in Newburgh.

Other major urban areas with density include San Francisco, Boston, Chicago, Miami, Philadelphia, Washington D.C. and Baltimore.

A few other major cities in the South come up short on density: Dallas, Houston, and Atlanta — these cities only have a handful of Census tracts that cross the 10,000 person per square mile threshold. Whether these cities can adapt and add density to their urban fabric may soon become a question of their very survival as major cities.

Secondary Cities

Many of the popular secondary cities that have grown by leaps and bounds in the past ten years are secondary cities with a fair amount of density, cities like Portland, New Orleans, and Seattle.

New Orleans: highly walkable, exceptionally stumble-able

These cities are attractive for many reasons, such as inherent walkability, and it’s difficult to have walkability without density. Some cities have density but little walkability: I was surprised to see density in Phoenix, Las Vegas, and Detroit. Some larger, older cities, like Denver, Pittsburgh, and Cleveland have more density than you might imagine, too.

Pittsburgh — dense like steel

Together, these secondary cities — a list that also includes Cincinnati, Columbus, Nashville, Memphis, Tampa, Sacramento, Kansas City, Grand Rapids, and others — represent the leading edge of development and growth in American cities today. These cities balance some of the density, culture, and attractions of larger cities like New York with more opportunities for growth, development, and community. As they are all already accustomed to some degree of density, I predict that these cities would welcome more and will continue to grow in the years to come.

Old Cities

Another type of city where I consistently found density? Why, that would be in old cities and towns, places developed before the automobile took over urban development. Even in some small cities with less than 50,000 residents, I found a few communities that still have the density that defines our larger urban areas. These cities present great opportunities for people seeking even smaller, tighter communities with even more affordable options for housing.

In the West — specifically, in California’s Central Valley, the Breadbasket of the Nation — I found a string of towns along California State Route 99, from Sacramento down to Bakersfield, which each have small pockets of density. Stockton, Modesto, Fresno, Delano: I would have never guessed that these cities would have any amount of density. Seems that the early siren calls of agriculture and oil in the area led to the creation of several cities that today have more density than one might guess.

There are similar cities in the Midwest, all united by trade on the Mississippi and Missouri Rivers. Trade from Omaha and Kansas City on the Missouri would feed into the Mississippi at St. Louis. Other cities were close to the Mississippi, like Lincoln, Iowa City, and Springfield, Illinois. Farther north, Milwaukee and Minneapolis grew as gateways to the animal and lumber treasures of the North. More famous for its beer and Brewers, Milwaukee stunned me with high levels of density all around its core.

Milwaukee put a bird on it (the bird being the Art Museum) well before Portland, Oregon, ever did

Finally, the East. Given that the Northeast of the United States was settled first, it’s not shocking that there are many old cities in this region of the country. It is shocking to see just how many of those cities beyond Boston and New York have great clusters of population density. From Buffalo to Rochester to Syracuse, upstate New York has a string of old, dense, and rather large cities. Nearby Erie is a relic of the old Canal that connected the Great Lakes to the Eastern Seaboard. Stamford, Bridgeport, New Haven, Hartford, and Springfield are all connected by Interstate 91 and the Connecticut River. It may not be remarkable that Providence has density, but I was surprised to see density in nearby small towns Fall River and New Bedford. Finally, around Boston, lesser known cities like Worcester, Lowell, Lawrence, and Manchester all have dense urban cores.

Providence provides providential population density

To find the future favorite cities of the country, we’d do well to look to the past. These cities, built well before cars were popular, built when horses were a luxury for the few, have the narrow, winding roads, the dense brick buildings oozing character, and the density that will support a more sustainable, more human, future.

College Towns

Finally, it’s little surprise that college towns support high levels of density. What’s not to love about them? Imagine in your mind’s eye the typical college town: dense housing, walkable neighborhoods, tree-lined walks and myriad parks with hardly a car in sight. Isn’t this the urban ideal that we’re chasing? Beyond their small sizes, close-knit communities, and high levels of educational and economic achievement, college towns fit the design of the ideal city for many.

Ann Arbor, Michigan (University of Michigan), Lawrence, Kansas (University of Kansas), and Durham, North Carolina (Duke) are all larger cities built around a major college. These colleges attract talent from around the world and generate high-tech businesses and high-paying jobs for these towns. Meanwhile, dense, walkable downtowns with character, entertainment, restaurants and bars (for the grad students, of course) attract prospective and current students alike.

Ann Arbor, Lawrence, and Durham

Some other towns are entirely centered around the college, like Corvallis, Oregon (Oregon State University), Morgantown, West Virginia (West Virginia University), and Ithaca, New York (Cornell). These towns are typically remote outposts, small and peaceful, places where students and instructors can focus on their studies. By my count, there are at least thirty towns and cities across the country that have population density focused on an anchor college. As economic growth continues to focus on technological, complex jobs, expect more business to turn toward these livable college towns for future growth.

Where Density Isn’t

Let’s take one moment to survey where density is hard to find.

Cities in Montana, Idaho, and the northern Plains states are largely free of any amount of density. Only two cities in these four states have neighborhoods with more than 10,000 people per square mile: Pullman, Washington, and Rexburg, Idaho (home to Brigham Young University-Idaho). Not on this map: Boise, Billings, Fargo, or Sioux Falls, all cities with populations over 100,000. Why don’t cities in this part of the country have levels of population density as high as other cities? Perhaps it’s all the wide-open space; perhaps it’s the bitter cold winters.

…at least Fargo has an indie movie theater?

Some cities in the southern Plains states are also light on density: Oklahoma City, Tulsa, and Little Rock, Arkansas, primary among them. Many cities in the old South are also much less dense than I would have guessed. Of Jacksonville, Birmingham, Macon, Augusta, Spartanburg, Asheville, Greensboro, and Raleigh, not one has a Census tract with population density passing 10,000 people per square mile. Finally, once east of Hempstead, Long Island is shockingly sparse given its proximity to the densest city in the nation. Despite the presence of the Long Island Railroad —with 124 stations and over 700 miles of track — Long Island remains resolutely suburban.

Levittown, New York: the ur-Suburb

These cities have a choice to make; if our future lies in denser, walkable cities and communities — and I believe it does — these cities will have to retool, rezone, and rebuild to adapt to the economic and environmental demands of the twenty-first century. They do, at least, have at least one great asset: an abundance of space on which to rebuild.

As for the other cities I covered? Those cities, from New York to New Haven, are well-positioned to adapt to the demands of the twenty-first century. When we search for tomorrow’s favored cities, why not start with cities that have already accepted and even embraced density? Why not foster more and better density in those cities, with sufficient housing and transportation options that go beyond the personal car? As a real estate developer looking for a great investment — as an activist looking to improve everyone’s lot — as a founder of a last-mile transportation company looking for a place to experiment and grow — I’d look to invest in cities that already have density.

Yes, even Cleveland.

Thanks for reading this post! If you’re curious about the data behind this post, check out this CSV of all Census tracts in the U.S. with more than 10,000 people per square mile. The sheet also has latitude and longitude data so you can map and explore the data; I recommend

I’m exploring cities and telling their stories through quantitative and qualitative frames. Subscribe here if you want to follow along and reach out to me if you want to chat.

Thanks for reading!



Karl Sluis

Cities, mobility, and product leadership in New York City