Urban cores are much celebrated but in reality most of the population living in functional urban cores is strongly concentrated in just a handful of major metropolitan areas in the United States. This conclusion is based on an analysis using the City Sector Model, which uses functional characteristics, rather than municipal jurisdictions, to analyze urban core and suburban components of metropolitan areas.
Functional Classifications of Metropolitan Areas
The City Sector Model allows a more representative functional analysis of urban core, suburban and exurban areas, by the use of smaller areas, rather than municipal boundaries.
The nearly 9,000 zip code tabulation areas of major metropolitan areas are categorized by functional characteristics, including urban form, density, and travel behavior. There are four functional classifications, the urban core, earlier suburban areas, later suburban areas and exurban areas. The urban cores have higher densities, older housing and substantially greater reliance on transit, similar to urban cores that existed before the post-World War II automobile oriented suburbanization. Exurban areas are beyond the built up urban areas. The suburban areas constitute the balance of the major metropolitan areas. Earlier suburbs include areas with a median house construction date before 1980. Later suburban areas have later median house construction dates.
Concentrating in New York and A Few Other Areas
As is so often the case on dense urbanization, the statistics are dominated by New York urban core which accounts for 42 percent of the total urban core population for the whole country. The New York metropolitan area, with 19.6 million people represents roughly six percent of the country’s population but its urban core –some 10.2 million strong – is larger than the total population of every metropolitan area in the nation other than Los Angeles (12.8 million).
New York's dominance is not surprising, reflecting its unique history and development. Four of the core city's five boroughs (Brooklyn, Queens, Manhattan, and the Bronx) have higher population densities than any municipality more than one-one hundredth its size in the United States. Significantly, unlike most major metropolitan areas, New York's functional urban core stretches well beyond the core city, and includes more than 2,000,000 residents outside New York City.
Another 36 percent of the nation’s urban core population is in six metropolitan areas, though none reaches a population close to that of New York (Figure 1). Chicago is second, with an urban core population of 2.4 million. Four other urban cores exceed 1,000,000 population, including Boston (1.6 million), Philadelphia (1.5 million), Los Angeles (1.3 million) and San Francisco (1.1 million). The seventh largest urban core is in Washington, at 900,000. These seven metropolitan areas include the six transit legacy cities (municipalities), which account for 55 percent of the transit work trip destinations and 99 percent of the increase in urban core transit commuting in the United States over the past 10 years.(Los Angeles is not classified as a transit legacy city).
After Washington, the size of urban cores drops off markedly with the next 45 largest metropolitan areas accounting for only 22 percent of the urban core population. Cleveland ranks eighth at 460,000, Baltimore is ninth at 440,000, and Minneapolis-St. Paul is 10th with 420,000 urban core residents. Perhaps surprisingly, Providence, which is the nation's 38th largest metropolitan area, ranks 11th in urban core population, at 410,000 residents. Pittsburgh, Milwaukee, Buffalo, and St. Louis round out the top 15, with between 320,000 and 370,000 urban core residents (Figure 2).
Another 9 metropolitan areas have urban core populations exceeding 100,000:Detroit, Seattle, Cincinnati, Portland, Hartford, New Orleans, Rochester, Kansas City, and Louisville.
Urban Cores over 100,000 Population
Approximately 97 percent of the urban core population lives in the 24 major metropolitan areas with more than 100,000 urban core residents. Between 2000 and 2010, the urban core populations in these areas dropped from 25.3 percent to 24.0 percent of their respective metropolitan populations. The continued decentralization of these metropolitan areas is illustrated by a loss in the earlier suburban areas and gains in the later suburban areas and exurban areas (Figure 3).
By comparison, only one percent of the population was in the urban cores of the other 28 major metropolitan areas (fewer than 100,000 residents in the urban core).
New York had by far the largest percentage of its total metropolitan population in the urban core, at 52 percent. Boston ranked second, with 34 percent of its population in the urban core. Buffalo, which was ranked only 47th in metropolitan area population, was third in urban core population share (29 percent). Chicago and San Francisco had 26 percent of their population in the urban cores, followed by Providence and Philadelphia at 25 percent (Figure 4).
Description of the Largest Urban Cores
There is substantial variation in the geographical extent of the largest urban cores relative to their corresponding historical core municipalities. This is described below and illustrated in the just published Demographia City Sector Model Metropolitan Area Maps.
As would be expected, New York's urban core includes nearly all of the city of New York. Virtually all of Brooklyn, Manhattan, the Bronx, and Queens are in the urban core, though only parts of Staten Island are included. The urban core extends into New Jersey, with nearly all of Hudson County (including Jersey City) included, the core of Essex County (including Newark) and the city of Elizabeth (in Union County). The urban core and extends into Long Island's Nassau County, including Hempstead, Valley Stream, Rockville Center and other areas. To the north, the urban core extends to parts of Westchester County (such as Yonkers, Pelham, Mount Vernon and New Rochelle). Interestingly, many of these areas, such as in western Nassau County, parts of Essex County and southern Westchester County are also suburban in form, but are classified as urban core because of high transit market shares, higher densities or pre-war development.
Chicago's urban core, the second largest, extends beyond but also excludes parts of the city of Chicago. The urban core extends into adjacent areas, such as older “suburban” Evanston, Oak Park and Cicero. There is also a significant urban core in northwestern Indiana, centered on East Chicago and Hammond.
Boston's urban core extends far outward from the city of Boston, including much of the area inside Route 128 (Interstate 95). This area also includes cities such as Cambridge, Everett, Somerville, Quincy, Medford, Waltham, and Lynn.
Philadelphia's urban core is largely confined to the city of Philadelphia, with extensions into Delaware County, Pennsylvania and Camden County, New Jersey.
The urban core of Los Angeles is principally in the area extending from Hollywood to parts of East Los Angeles and south to the Interstate 105 freeway. However, much more of the city of Los Angeles is not in the urban core. The urban core also includes parts of Beverly Hills, West Los Angeles, Pasadena and Glendale.
The urban core of San Francisco includes most of the cities of San Francisco and Oakland, as well as much of Berkeley, Albany, and Emeryville.
Washington's urban core includes most of Washington (the District of Columbia) and extends into Arlington and Alexandria in Virginia and has a large extension into Montgomery County, Maryland, including areas such as Bethesda and Silver Spring.
Urban Cores Compared to Historical Core Municipalities
A comparison of functional urban core populations to the populations of historical core municipalities indicates the problem of relying on jurisdictional (municipal) boundaries for urban core analysis. Functional urban core and historical core municipality populations vary significantly (Figure 5). The greatest differences are in Boston and Louisville. Boston's functionalurban core population is 2.52 times that of the historical core municipality (Boston). Louisville's functional urban core population is only one-sixth that of the historical core municipality (Louisville).
Providence is second to Boston in its ratio of urban core population to that of historical core municipality at 2.29. The city of Providence had only 178,000 residents in 2010. (Among historical core municipalities, only Hartford was smaller at 125,000). Washington has an urban core population 1.49 times that of the historical core municipality, while New York and Buffalo had urban cores 1.25 times the population of their historical core municipalities.
Among urban cores with more than 100,000 population Kansas City, Los Angeles, Portland, and New Orleans follow Louisville with the lowest ratios to historical core municipality populations (from 24 percent to 37 percent). In each of these cases, the urban core's low ratio is the result of substantial annexations or large areas or the settling of large rural territories that had been previously included in the municipal limits (such as Los Angeles and New Orleans).
Urban Cores: Products of History
Indeed, nothing distinguishes the major metropolitan areas with larger urban core populations from the rest than history, In1940, just before the great mobility and suburbanization revolution, there were 23 metropolitan areas in the United States with wore than 500,000 population. The major metropolitan areas with the 19 largest urban cores in 1940 were all among the 23 with more than 500,000 population in 1940. Out of the 24 major metropolitan areas with more than 100,000 urban core residents in 2010, 21had more than 500,000 population in 1940 (only Hartford, Rochester and Louisville had smaller populations).
Conversely, only two of the 28 major metropolitan areas in 2010 with fewer than 100,000 functional urban core residents had more than 500,000 residents in 1940, and they were among the smaller (Houston with 528,000 and Atlanta with 518,000).
Urban cores were not planned, but rather were the result of consumer trendsin a time of much lower household incomes and much more restricted personal mobility. Many of the very centers of urban cores are reviving, but overall core growth continues to lag behind that of metropolitan areas. Moreover, there are no significant new ones.Urban cores, as much as anything, are a product of history.
Wendell Cox is principal of Demographia, an international public policy and demographics firm. He is co-author of the "Demographia International Housing Affordability Survey" and author of "Demographia World Urban Areas" and "War on the Dream: How Anti-Sprawl Policy Threatens the Quality of Life." He was appointed to three terms on the Los Angeles County Transportation Commission, where he served with the leading city and county leadership as the only non-elected member. He was appointed to the Amtrak Reform Council to fill the unexpired term of Governor Christine Todd Whitman and has served as a visiting professor at the Conservatoire National des Arts et Metiers, a national university in Paris.
Illustration: Core of the New York metropolitan area (City Sector Model map)