New Geography

Tag: City Sector Model

  • Dispersing Millennials

    The very centers of urban cores in many major metropolitan areas are experiencing a resurgence of residential development, including new construction in volumes not seen for decades. There is a general impression, put forward by retro–urbanists (Note 1) and various press outlets that the urban core resurgence reflects a change in the living preferences of younger people – today’s Millennials – who they claim are rejecting the suburban and exurban residential choices of their parents and grandparents.

    There is no question that the millennial population has risen in urban cores in recent years. Yet the growth in the younger population in urban cores masks far larger increases in the same population group in other parts of major metropolitan areas and in the nation in general.

    Functional Analysis of Metropolitan Areas

    This article continues a series examining the 52 major metropolitan areas (those with more than 1,000,000 residents) using the City Sector Model, which allows a more representative functional analysis of urban core, suburban, and exurban areas, by using smaller areas, rather than using municipal boundaries. The City Sector Model thus eliminates the over-statement of urban core data that occurs in conventional analyses, which rely on historical core municipalities, most of which encompass considerable suburbanization.

    The City Sector Model classifies 9,000 major metropolitan area zip code tabulation areas using urban form, density, and travel behavior characteristics. 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 the urban cores that preceded the great automobile oriented post-World War Two 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 (Note 2).

    20-29s and the Urban Core

    The age band best approximating millennials for the period of 2000 to 2010 is people of from 20 to 29 years of age.

    Between 2000 and 2010, the total population of 20-29’s living in the functional urban cores increased by 300,000, from 4.3 million to 4.6 million from 2000 to 2010. Yet, the share of 20-29s living in the urban cores actually declined over the decade.

    In 2000, 20.2 percent of the major metropolitan area 20- to 29-year-old population was in the urban core. By 2010, it had dropped to 19.3 percent, a 4.4 percent share reduction. This happened because the 300,000 increase in 20-29s in the urban core was dwarfed by the overall 2.6 million increase in the same age group throughout the major metropolitan areas. As a result, only 12 percent of the 20-29 population growth was in the urban core, 40 percent below its 2000 share.

    While 80 percent of the 20-29s lived outside the urban cores in 2000, 88 percent of the 20-29 population growth was outside the urban core between 2000 and 2010 (Figure 1). Overall, the suburban and exurban millennial population grew nearly 8 times than in the urban core.

    The 20-29s and the Balance of Major Metropolitan Areas

    The trend among the 20-29s also tended away from the areas adjacent to the urban cores. These tend to be   earlier suburban areas (generally with median house construction dates before 1980). Between 2000 and 2010, the share of 20-29s living in the earlier suburbs fell from 46.1 percent to 42.0 percent. This was double the urban core loss noted above (4.4 percent), at 8.9 percent.

    At the same time, millennials, long said to hate suburbs, have embraced dispersion. The more recently built suburban areas saw their share of 20-29s rise from 20.6 percent to 24.4, an 18 percent gain. A smaller gain was registered in exurban areas, where the share of 20-29s rose from 13.2 percent to 14.3 percent; an 8 percent share gains (Figure 2).

    The net effect from 2000 and 2010: a full five percent more of all 20-29s in major metropolitan areas lived in the later suburban and exurban areas, while 5 percent fewer lived in the urban cores and earlier suburbs. The later suburbs and exurbs added 1,500,000 more 20-29s than the urban core and earlier suburbs.

    Millennials and the Nation

    The numbers of 20-29s continued to increase in the rest of the nation’s small towns and cities, as well as rural areas. In 2000, approximately 44.6 percent of the 20-29 population lived outside the major metropolitan areas. In the next decade, these areas added 20-29s at a lower rate (40.9 percent of the increase), yet this was enough to keep the share of 20-29s at 44.2 percent. In 2010, more than four times as many 20-29s lived outside the major metropolitan areas as lived in the urban cores. Between 2000 and 2010, the growth in 20-29’s living outside the major metropolitan areas was almost six times the growth in the urban cores (Figure 3).

    Overall, only 7 percent of the growth in the 20-29 age group was in the functional urban cores between 2000 and 2010. That left 93 percent of the growth to be outside the urban core (Figure 4).

    Consistency with Other Research

    The trend among the 20-29s in the urban core may seem surprising. However, it is consistent with an analysis of 2000-2010 data by the US Census Bureau, which indicated that the population gains within two miles of the city halls of the largest cities were more than offset by losses in the ring between two and five miles from City Hall. While the gains in the course of the urban cores are impressive, they are much smaller when considered in the context of the entire urban core and even smaller in the context of the entire metropolitan area.

    More recent data suggests the dispersion of Millennials is continuing. According to Jed Kolko, Chief Economist at Trulia.com Millennials located in larger numbers in suburban areas  than in the urban cores between 2012 and 2013 (more recent data for the city sector analysis is not yet available) 

    Dispersing, But Not Quite as Quickly

    Essentially what we see here is myopic prejudices of contemporary journalism. More than 300,000 new 20-29 residents in the urban cores was more than enough to be noticed by analysts and reporters, since that’s where many of them spend much of their time. Moreover, the share of 20-29s living in urban cores dropped less than one-half the rate for all ages in the urban core.

    Simply put, despite the conventional wisdom, 20-29s are not abandoning the suburbs and exurbs for the urban core. The data indicates that the 20-29s have been more inclined to choose the urban core than other age groups, but not enough to prevent their overwhelming numbers living in suburban and exurban communities. Nor has this inclination been sufficient to counter the continuing relative decline in the urban core among the 20-29s.

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    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.

    Note 1: The term retro-urbanist is applied to the currently popular strain of urban planning that favors urban cores over the rest of the urban area and metropolitan area (the suburbs and exurbs).

    Note 2:. The previous articles in this series are:
    From Jurisdictional to Functional Analyses of Urban Cores & Suburbs
    The Long Term: Metro American Goes from 82 percent to 86 percent Suburban Since 1990
    New York, Legacy Cities Dominate Transit Urban Core Gains
    Functional v. Jurisdictional Analysis of Metropolitan Areas
    City Sector Model Small Area Criteria

  • New York, Legacy Cities Dominate Transit Urban Core Gains

    Much attention has been given the increase in transit use in America. In context, the gains have been small, and very concentrated (see: No Fundamental Shift to Transit, Not Even a Shift). Much of the gain has been in the urban cores, which house only 14 percent of metropolitan area population. Virtually all of the urban core gain (99 percent) has been in the six metropolitan areas with transit legacy cities (New York, Chicago, Philadelphia, San Francisco, Boston, and Washington).

    In recent articles, I have detailed a finer grained, more representative picture of urban cores, suburbs and exurbs than is possible with conventional jurisdictional (core city versus suburban) analysis. The articles published so far are indicated in the "City Sector Articles Note," below.

    Transit Commuting in the Urban Core

    As is so often the case with transit statistics, recent urban cores trends are largely a New York story. New York accounted for nearly 80 percent of the increase in urban core transit commuting. New York and the other five metropolitan areas with "transit legacy cities" represented more than 99 percent of the increase in urban core transit commuting (Figure 1). This is not surprising, because the urban cores of these metropolitan areas developed during the heyday of transit dominance, and before broad automobile availability. Indeed, urban core transit commuting became even more concentrated over the past decade. The 99 percent of new commuting (600,000 one-way trips) by transit in the legacy city metropolitan areas was as well above their 88 percent of urban core transit commuting in 2000.

    New York’s transit commute share was 49.7 percent in 2010, well above the 27.6 percent posted by the other five metropolitan areas with transit legacy cities. The urban cores of the remaining 45 major metropolitan areas (those over 1,000,000 population) had a much lower combined transit work trip market share, at 12.8 percent.

    The suburban and exurban areas, with 86 percent of the major metropolitan area population, had much lower transit commute shares. The Earlier Suburban areas (generally median house construction dates of 1946 to 1979, with significant automobile orientation) had a transit market share of 5.7 percent, the Later Suburban areas 2.3 percent and the Exurban areas 1.4 percent (Figure 2).

    The 2000s were indeed a relatively good decade for transit, after nearly 50 years that saw its ridership (passenger miles) drop by nearly three-quarters to its 1992 nadir. Since that time, transit has recovered 20 percent of its loss. Transit commuting has always been the strongest in urban cores, because the intense concentration of destinations in the larger downtown areas (central business districts) that can be effectively served by transit, unlike the dispersed patterns that exist in the much larger parts of metropolitan areas that are suburban or exurban. Transit’s share of work trips by urban core residents rose a full 10 percent, from 29.7 percent to 32.7 percent (Figure 3).

    There were also transit commuting gains in the suburbs and exurbs. However, similar gains over the next quarter century would leave transit’s share at below 5 percent in the suburbs and exurbs, because of its small base or ridership in these areas.

    Walking and Cycling

    The share of commuters walking and cycling (referred to as "active transportation" in the Queen’s University research on Canada’s metropolitan areas) rose 12 percent in the urban core (from 9.2 percent to 10.3 percent), even more than transit. This is considerably higher than in suburban and exurban areas, where walking and cycling remained at a 1.9 percent market share from 2000 to 2010.

    Working at Home

    Working at home (including telecommuting) continues to grow faster than any work access mode, though like transit, from a small base. Working at home experienced strong increases in each of the four metropolitan sectors, rising a full percentage point or more in each. At the beginning of the decade, working at home accounted for less work commutes than walking and cycling, and by 2010 was nearly 30 percent larger.

    The working at home largest gain was in the Earlier Suburban Areas, with a nearly 500,000 person increase. Unlike transit, working at home does not require concentrated destinations, effectively accessing employment throughout the metropolitan area, the nation and the world. As a result, working at home’s growth is fairly constant across the urban core, suburbs and exurbs (Figure 4). Working at home has a number of advantages. For example, working at home (1) eliminates the work trip, freeing additional leisure or work time for the employee, (2) eliminates greenhouse gas emissions from the work trip, (3) expands the geographical area and the efficiency of the labor market (important because larger labor markets tend to have greater economic growth and job creation, and it does all this without (4) requiring government expenditure.

    Driving Alone

    Despite empty premises about transit’s potential, driving remains the only mode of transport capable of comprehensively serving the modern metropolitan area. Driving alone has continued its domination, rising from 73.4 percent to 73.5 percent of major metropolitan area commuting and accounting for three quarters of new work trips. In the past decade, driving alone added 6.1 million commuters, nearly equal to the total of 6.3 million major metropolitan area transit commuters and more than the working at home figure of 3.5 million. To be sure, driving alone added commuters in the urban core, but lost share to transit, dropping from 45.2 percent to 43.4 percent. In suburban and exurban areas, driving alone continued to increase, from 78.2 percent to 78.5 percent of all commuting.).

    Density of Cars

    The urban cores have by far the highest car densities, despite their strong transit market shares. With a 4,200 household vehicles available per square mile (1,600 per square kilometer), the concentration of cars in urban cores was nearly three times that of the Earlier Suburban areas (1,550 per square mile or  600 per square kilometer) and five times that of the Later Suburban areas (950 per square kilometer). Exurban areas, with their largely rural densities had a car density of 100 per square mile (40 per square kilometer).

    Work Trip Travel Times

    Despite largely anecdotal stories about the super-long commutes of those living in suburbs and exurbs, the longest work trip travel times were in the urban cores, at 31.8 minutes one-way. The shortest travel times were in the Earlier Suburbs (26.3 minutes) and slightly longer in the Later Suburbs (27.7 minutes). Exurban travel times were 29.2 minutes. Work trip travel times declined slightly between 2000 and 2010, except in exurban areas, where they stayed the same. The shorter travel times are to be expected with the continuing evolution from monocentric to polycentric and even "non-centric" employment patterns and a stagnant job market (Figure 5).

    Contrasting Transportation in the City Sectors

    The examination of metropolitan transportation data by city sector highlights the huge differences that exist between urban cores and the much more extensive suburbs and exurbs. Overall the transit market share in the urban core approaches nine times the share in the suburbs and exurbs. The walking and cycling commute share in the urban core is more than five times that of the suburbs and exurbs. Moreover, the trends of the past 10 years indicate virtually no retrenchment in automobile orientation, as major metropolitan areas rose from 84 percent suburban and exurban in 2000 to 86 percent in 2010. This is despite unprecedented increases is gasoline prices and the disruption of the housing market during worst economic downturn since the Great Depression.

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    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.

    Photograph: DART light rail train in downtown Dallas (by author)

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    City Sector Note: Previous articles in this series are listed below:
    From Jurisdictional to Functional Analyses of Urban Cores & Suburbs
    The Long Term: Metro American Goes from 82 percent to 86 percent Suburban Since 1990
    Functional v. Jurisdictional Analysis of Metropolitan Areas
    City Sector Model Small Area Criteria

  • The Long Term: Metro America Goes From 82% to 86% Suburban Since 1990

    The major metropolitan areas of the United States experienced virtually all of their overall growth in suburban and exurban areas between 2000 and 2010. This is the conclusion of an analysis of the functional Pre-Auto Urban Cores and functional suburban and exurban areas using the Demographia City Sector Model.

    The City Sector Model
    The City Sector Model classifies zip code areas in the major metropolitan areas based on urban form (Note 1). These include four classifications, one of which replicates the urban form and travel behavior typical of the pre-World War II urban cores. These areas were typically higher density and dependent on transit and walking. The City Sector Model has three other classifications, Pre-Auto Urban Core, Auto-Suburban: Earlier, Auto-Suburban: Later and Auto-Exurban.

    For simplicity the City Sector categories are referred to as urban core, earlier suburban, later suburban and exurban. The City Sector Model is described in a previous article, and illustrated in Figure 1, which is also posted to the internet.

    The model makes it possible to analyze metropolitan areas based on smaller area functional classifications, rather than on jurisdictional (historical core municipality) borders, which among other things, mask as core large areas of suburbanization.

    Suburbanized Core Municipality Examples: San Jose and Charlotte

    This suburbanization in the historical core municipalities is illustrated by examples like San Jose and Charlotte. The City Sector Model indicates that neither of these metropolitan areas has a pre-auto urban core. This is because neither metropolitan area has a large enough concentration of houses with a median construction date of 1945 or before or sufficient area of 7,500 population density per square mile (2,900 per square kilometer) with a transit, walking and cycling work trip market share of at least 20 percent. As a result, virtually all of both metropolitan areas is automobile oriented suburban, including virtually all of the core municipalities.

    This is true in Charlotte despite its development of one of the most impressive new central business districts in the nation, with high employment densities. Yet at the same time the  core city of Charlotte itself is very low density (2010), at 2,500 per square mile (950 per square kilometer), less than the suburban area average for large US urban areas (2,600 per square mile or 1,000 per square kilometer). Charlotte, however, could develop the equivalent of a pre-auto urban core if its central population density rises enough and enough commuters use transit, walking and cycling.

    The core city of San Jose is far more dense than Charlotte, at 5,800 per square mile (2,200 per square kilometer). However, it is less dense than the suburbs of Los Angeles (6,400 per square mile or 2,500 per square mile). Like Charlotte, the core city of San Jose is virtually all automobile oriented suburban and has a transit work trip market share a full third below the major metropolitan area average.

    Overall Population Trend: 2000-2010

    These phenomena reflect national trends, All major metropolitan area growth between 2000 and 2010 (100.9 percent) was in the functional suburbs and exurbs.

    Between 2000 and 2010, the percentage of major metropolitan area population in the urban cores declined from 16.1 percent to 14.4 percent. The urban cores lost approximately 140,000 residents (a loss of 0.6 percent), despite strong gains very close to the centers of the historical core municipalities. Consistent with these findings, Census Bureau analysis showed that the focused gains in the cores of the urban cores were more than negated by losses in surrounding urban core areas (described in: Flocking Elsewhere: The Downtown Growth Story).

    The earlier suburban areas gained only modestly, adding 280,000 new residents, for a 0.4 percent increase. These areas have median house construction dates between 1946 and 1979. The largest increase was in the later suburban areas, which added the most new residents, 11.4 million, for a gain of 33.4 percent. The later suburban areas have median house constructions of 1980 or later. Exurban areas added 5.0 million residents, for a gain of 21.3 percent. Exurban areas are located outside the principal urban areas (Figure 2).

    Overall, the later suburban and exurban areas gained 16.4 million residents, compared to the combined gain of 130,000 in the urban cores and earlier suburban areas. Thus, more than 99 percent of the population growth in the major metropolitan areas was in the later suburban and exurban areas (Figure 3).

    During the decade, the exurban areas overtook the urban cores in population, rising from 15.4 percent of the major metropolitan area population to 16.8 percent (Figure 4).

    Contrast with 1990-2000 Population Trend

    Despite all of the talk of an urban core renaissance, the 2000 to 2010 decade was less favorable for urban cores than the 1990 to 2000 decade. In the earlier decade, the urban cores (as defined in 2010) added 960,000 residents, for a growth rate of 4.0 percent. This compares to the 140,000 urban core loss between 2000 and 2010 (Note 2).

    Virtually all of the difference was attributable to urban core population trend reversals in New York, Boston and Chicago, which combined experienced a drop in growth of 1.1 million. Between 1990 and 2000, the urban core of New York added 779,000 residents, far more than the 190,000 added between 2000 and 2010. Boston’s 1990-2000 urban core growth was 296,000, but fell to 27,000 in the last decade. Chicago’s urban core dropped from a gain of 139,000 to a loss of 175,000.

    Over the past twenty years, the population of urban cores has diminished relative to that of major metropolitan areas. In 1990, the urban cores represented 18.1 percent of the population, but fell to 14.1 percent in 2010. Auto-oriented areas (suburban and exurban) have increased their combined share from 81.9 percent of the major metropolitan area population in 1990 to 85.6 percent in 2010 (Figure $$$).

    Summary of Individual Metropolitan areas

    In 30 of the 52 major metropolitan areas, all or more of the population growth was in suburban and exurban areas between 2000 and 2010. This includes the metropolitan areas that do not have Pre-Auto Urban Cores.

    Chicago had the largest share of suburban and exurban population growth, at 148 percent. This occurred because of the substantial urban core population losses. The suburbs and exurbs of Providence captured 131 percent of its growth, slightly more than the 126 percent suburban and exurban share in St. Louis. Baltimore, Rochester and Milwaukee had more than 110 percent of their growth in the suburbs and exurbs. Cincinnati, Indianapolis, Louisville, and Kansas City rounded out the largest suburban and exurban growth shares, all over 105 percent.

    Despite the substantial decline in its urban core growth in the last decade, New York had the lowest share of population growth in the suburbs and exurbs (meaning that it had the highest share of population growth in the urban core). The suburbs and exurbs of New York captured only 69 percent of the metropolitan area growth, well below second place, Virginia Beach – Norfolk (81 percent). Boston was next at 83 percent, followed by San Francisco – Oakland, at 88 percent. The bottom 10 in suburban and exurban growth share also included Seattle, Washington, Philadelphia, Richmond, Hartford and Portland. Even so, each of these six metropolitan areas had more than 90 percent of their growth in suburban and exurban areas (Figure 6).

    Jurisdictional Analyses: Suburbs Masquerading in Cities

    The functional analysis based on urban form and behavior reveals substantially different trends compared to the conventional jurisdictional analysis that compares historical core municipalities, principal cities or primary cities to the balance of metropolitan areas. For example a jurisdictional analysis shows that core municipalities added 1,290,000 residents between 2000 and 2010. In contrast, the urban cores, as indicated in the functional analysis, lost 140,000 residents. This indicates the extent of to which municipal boundaries can mislead in the analysis of urban form within metropolitan areas. The expansive city limits of most core cities masks the substantial automobile oriented suburbanization within their own borders.

    —-

    Note 1: The City Sector Model is generally similar to the groundbreaking research published by David L. A. Gordon and Mark Janzen at Queen’s University in Kingston Ontario (Suburban Nation: Estimating the Size of Canada’s Suburban Population) with regard to the metropolitan areas of Canada. Gordon and Janzen concluded that the metropolitan areas of Canada are largely suburban. Among the major metropolitan areas of Canada, the Auto Suburbs and Exurbs combined contain 76 percent of the population, somewhat less than the 86 percent found in the United States.

    Note 2: Changes in zip code definitions and boundaries could result in minor differences in comparability between the three censuses.

    —-

    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.

    Photo:  Later Suburbs in New York Urban Area (Morris County, New Jersey), by author

  • From Jurisdictional to Functional Analysis of Urban Cores & Suburbs

    The 52 major metropolitan areas of the United States are, in aggregate, approximately 86 percent suburban or exurban in function. This is the conclusion from our new City Sector Model, which divides all major metropolitan zip codes into four functional categories, based on urban form, population density and urban travel behavior. The categories are (1) Pre-Auto Urban Core, (2) Auto Suburban: Earlier, (3) Auto Suburban: Later and (4) Auto Exurban. It is recognized that automobile-oriented suburbanization was underway before World War II, but it was interrupted by the Great Depression during the 1930s and was small compared to the democratization of personal mobility and home ownership that has occurred since that time.

    For decades there has been considerable analysis of urban core versus suburban trends. However, for the most part, analysts have been jurisdictional, comparing historical core municipalities to the expanse that constitutes the rest of the metropolitan area. Most core municipalities are themselves substantially suburban, which can mask (and exaggerate) the size of urban cores.

    The Queen’s University Research

    The City Sector Model is generally similar to the groundbreaking research published by David L. A. Gordon and Mark Janzen at Queen’s University in Kingston Ontario (Suburban Nation: Estimating the Size of Canada’s Suburban Population) with regard to the metropolitan areas of Canada. Researchers used travel behavior (journey to work data from the 2006 census) and density for classifying metropolitan areas into four sectors, (1) Active Core, (2) Transit Suburbs, (3) Auto Suburbs, and (4) Exurbs. The active core was that portion of metropolitan areas with a high share of work trip travel by walking and cycling. I covered the research in a newgeography.com article last autumn.

    Gordon and Janzen concluded that the metropolitan areas of Canada are largely suburban. Among the major metropolitan areas of Canada, the Auto Suburbs and Exurbs combined contain 76 percent of the population, somewhat less than the 86 percent we found in the United States.

    The City Sector Model follows the same general approach as the Queens University research, although there are important differences. For example, the City Sector Model is principally aimed at identifying the Pre-Auto Urban Core component of the modern metropolitan area and does not identify an active core.

    All US Major Metropolitan Area Growth Has Been Suburban and Exurban

    Virtually all population growth in US metropolitan areas (as currently defined) has been suburban or exurban since before World War II (the 1940 census). The historical core municipalities that have not annexed materially and were largely developed by 1940 have lost population. As a result, approximately 110 percent of their metropolitan area growth has occurred in suburbs and exurbs. Further, among the other core municipalities, virtually all of the population growth that has occurred in annexed areas or greenfield areas that were undeveloped in 1940 (Figure 1).

    Identifying the Pre-Auto Urban Core

    The City Sector Model is not dependent upon municipal boundaries (the term "city" is generic, and refers to cities in their functional sense, metropolitan areas, or in their physical sense, urban areas). Not being constrained by municipal boundaries is important because core municipalities vary substantially. For example, the core municipality represents less than 10 percent of the population of Atlanta, while the core municipality represents more than 60 percent of the population of San Antonio. The City Sector Model applies data available from the US Census Bureau to estimate the population and distribution of Pre-Auto Urban Cores in a consistent manner.

    At the same time, the approach is materially different from the Office of Management and Budget (OMB) classification of "principal cities." It also differs from the Brookings Institution "primary cities," which is based on the OMB approach. The OMB-based classifications classify municipalities using employment data, without regard to urban form, density or other variables that are associated with the urban core. These classifications are useful and acknowledge that the monocentric nature of US metropolitan areas has evolved to polycentricity. However, non-urban-core principal cities and primary cities are themselves, with few exceptions, functionally suburban.

    The City Sector Model Criteria

    Due to media and academic interest in the Pre-Auto Urban Core, a number of data combinations were used to best fit the modeled population to that of the core municipalities that have virtually the same boundaries as in 1940 and that were virtually fully developed by that time (the Pre-War & Non-Suburban classification in historical core municipalities). A number of potential criteria were examined, and the following were accepted (Figure 2).

    The Auto Exurban category includes any area outside a principal urban area.

    The Pre-Auto Urban Core category includes any non-exurban with a median house construction date of 1945 or before and also included areas with a population density of 7,500 per square mile (2,900 per square kilometer) or more and with a transit, walk and cycling journey to work market share of 20 percent or more.

    The Auto Suburban Earlier category included the balance of areas with a median house construction date of 1979 or before.

    The Auto Suburban Later category later included the balance of areas with a median house construction date of 1980 or later.

    Additional details on the criteria are in Note 1

    Results: 2010 Census

    The combined Pre-Auto Urban Core areas represented 14.4 percent of the population of the major metropolitan areas in 2010 (2013 geographical definition). This compares to the 26.4 percent that the core municipalities themselves represented of the metropolitan areas, indicating nearly half of their population was essentially suburban.

    The Auto Suburban: Earlier areas accounted for 42.0 percent of the population, while the Auto Suburban: Later areas had 26.8 percent of the population. The Auto Exurban areas had 16.8 percent of the population (Figure 3).

    The substantial difference between US and Canadian urbanization is illustrated by applying an approximation of the Gordon-Janzen criteria, which yielded an 8.4 percent Pre-Auto Urban Core population. The corresponding figure for the six major metropolitan areas of Canada was 24.0 percent. This difference is not surprising, since major Canadian urban areas have generally higher densities and much more robust transit, walking and cycling market shares. Yet, the Gordon-Janzen research shows Canada still to be overwhelmingly suburban (Note 2).

    Population Density: As would be expected, the Pre-Auto Urban Core areas had the highest densities (Figure 4), at 11,000 per square mile (4,250 per square kilometer). The Auto Suburban: Earlier areas had a density of 2,500 per square mile (1,000 per square kilometer), while the Auto Suburban: Later had a population density of 1,300 per square mile (500 per square kilometer), while the Auto Exurban areas had a population density of 150 per square mile (60 per square kilometer)).

    Individual Metropolitan Areas (Cities)

    The metropolitan areas with the highest proportion of Pre-Auto Urban Core population are New York (more than 50 percent), and Boston (nearly 35 percent), followed by Buffalo, Chicago, San Francisco-Oakland, and Providence, all with more than 25 percent (Table).

    Table
    City Sectors: 2010
    Major Metropolitan Areas
    City (Metropolitan Area) Pre-Auto Urban Core Auto Suburban: Earlier Auto Suburban: Later Auto Exurban
    Atlanta, GA 0.5% 14.9% 70.7% 13.8%
    Austin, TX 1.8% 15.7% 62.5% 20.0%
    Baltimore, MD 16.2% 41.8% 19.9% 22.0%
    Birmingham, AL 0.0% 42.1% 24.6% 33.3%
    Boston, MA-NH 34.2% 49.7% 3.2% 12.9%
    Buffalo, NY 28.8% 51.6% 3.1% 16.5%
    Charlotte, NC-SC 0.0% 10.0% 38.4% 51.6%
    Chicago, IL-IN-WI 25.8% 45.0% 18.3% 10.9%
    Cincinnati, OH-KY-IN 10.1% 38.8% 24.3% 26.8%
    Cleveland, OH 22.2% 46.8% 10.5% 20.6%
    Columbus, OH 5.0% 28.7% 37.5% 28.9%
    Dallas-Fort Worth, TX 0.3% 34.4% 43.0% 22.4%
    Denver, CO 3.1% 42.9% 42.4% 11.6%
    Detroit,  MI 6.3% 60.6% 16.1% 16.9%
    Grand Rapids 3.8% 32.9% 15.3% 48.1%
    Hartford, CT 11.1% 58.6% 1.1% 29.2%
    Houston, TX 0.3% 34.2% 48.9% 16.6%
    Indianapolis. IN 4.6% 28.0% 41.8% 25.6%
    Jacksonville, FL 0.0% 26.4% 48.2% 25.4%
    Kansas City, MO-KS 5.4% 37.6% 26.3% 30.6%
    Las Vegas, NV 2.4% 17.5% 76.7% 3.5%
    Los Angeles, CA 10.4% 76.4% 5.2% 8.0%
    Louisville, KY-IN 8.1% 45.4% 25.6% 20.8%
    Memphis, TN-MS-AR 1.8% 40.6% 34.3% 23.3%
    Miami, FL 1.4% 51.4% 44.8% 2.4%
    Milwaukee,WI 22.1% 52.0% 10.4% 15.5%
    Minneapolis-St. Paul, MN-WI 12.7% 31.6% 33.8% 22.0%
    Nashville, TN 0.0% 25.0% 36.1% 38.9%
    New Orleans. LA 10.6% 49.9% 7.0% 32.4%
    New York, NY-NJ-PA 52.4% 35.3% 5.6% 6.7%
    Oklahoma City, OK 2.5% 35.1% 31.6% 30.8%
    Orlando, FL 0.0% 16.1% 50.5% 33.4%
    Philadelphia, PA-NJ-DE-MD 24.6% 51.1% 15.1% 9.2%
    Phoenix, AZ 0.0% 29.4% 51.7% 18.8%
    Pittsburgh, PA 15.7% 56.1% 4.8% 23.4%
    Portland, OR-WA 9.3% 36.7% 39.5% 14.6%
    Providence, RI-MA 25.5% 47.7% 2.8% 24.0%
    Raleigh, NC 0.0% 7.5% 54.4% 38.1%
    Richmond, VA 4.5% 38.8% 38.0% 18.8%
    Riverside-San Bernardino, CA 0.0% 29.1% 29.4% 41.4%
    Rochester, NY 11.1% 46.9% 7.7% 34.3%
    Sacramento, CA 1.6% 38.0% 40.2% 20.1%
    St. Louis,, MO-IL 11.7% 39.9% 25.7% 22.8%
    Salt Lake City, UT 4.6% 47.9% 38.4% 9.1%
    San Antonio, TX 0.1% 39.7% 42.6% 17.6%
    San Diego, CA 1.2% 61.6% 30.3% 6.9%
    San Francisco-Oakland, CA 25.7% 55.5% 7.6% 11.2%
    San Jose, CA 0.1% 77.7% 9.1% 13.1%
    Seattle, WA 7.8% 38.9% 40.2% 13.0%
    Tampa-St. Petersburg, FL 0.0% 44.8% 39.7% 15.5%
    Virginia Beach-Norfolk, VA-NC 1.5% 44.4% 37.7% 16.4%
    Washington, DC-VA-MD-WV 15.9% 29.2% 36.2% 18.7%
    Overall 14.4% 42.0% 26.8% 16.8%

     

    It may be surprising that many of the major metropolitan areas are shown with little or no Pre-Auto Urban Core population. For example, five metropolitan areas have virtually no Pre-Auto Urban Core population, including Phoenix, Riverside-San Bernardino, Tampa-St. Petersburg, Orlando, Jacksonville, and Birmingham. By the Census Bureau criteria of 1940, two of these areas were not yet metropolitan and only Birmingham (400,000) had more than 250,000 residents.  Many of the newer and fastest growing metropolitan areas were too small, too sparsely settled or insufficiently dense to have strong urban cores before the great automobile suburbanization that followed World War II. Further, many of the Pre-Auto Urban Cores have experienced significant population loss and some of their neighborhoods have become more suburban (automobile oriented). Virtually no urban cores have been developed since World War II meeting the criteria.

    Thus, no part of Phoenix, San Jose, Charlotte and a host of other newer metropolitan areas functionally resembles the Pre-Auto Urban Core areas of metropolitan areas like Chicago, Cincinnati, or Milwaukee. However, new or expanded urban cores are possible, if built at high enough population density and with high enough transit, walking, and cycling use. 

    Examples of three differing metropolitan areas are provided. Philadelphia (Figure 5) is a metropolitan area with a strong Pre-Auto Urban Core, which is indicative of an older metropolitan area that has been among the largest in the nation since its inception, Seattle (Figure 6) is a much newer metropolitan area, yet exhibits a larger Pre-Auto Urban Core than most. Phoenix (Figure 7) may be the best example of a post-War metropolitan area, with virtually no Pre-Auto Urban Core. In 1940, the Phoenix metropolitan area had only 120,000 residents and could be 40 times that large by 2020. Virtually all of Phoenix is automobile-oriented. Even three years after opening its light rail line, 88 percent of Phoenix commuters go to work by car and only two percent by transit, virtually the same as in 2000.

    Despite the comparatively small share of the modern metropolitan area represented by the Pre-Auto Urban Core in the City Core Model, the definition is broad and, if anything over-estimates the size of urban core city sectors. The population density of Pre-Auto Urban Core areas is below that of the historical core municipalities before the great auto oriented urbanization (11,000 compared to 12,100 in 1940) and well above their 2010 density (8,400), even when New York is excluded. The minimum density requirement of 7,500 per square mile (not applied to analysis zones with a median house construction data of 1945 or earlier) is slightly less than the density of Paris suburbs (7,800 per square mile or 3,000 per square kilometer) and only 20 percent more dense than the jurisdictional suburbs (suburbs outside the historical core municipality) of Los Angeles (6,400 per square mile or 2,500 per square kilometer). Some urban containment plans require higher minimum densities, not only in urban cores but also in the suburbs.

    In describing the Canadian results, Professor Gordon noted that there is a tendency to “overestimate the importance of the highly visible downtown cores and underestimate the vast growth happening in the suburban edges.” That is true to an even greater degree in the United States. 

    —–

    Note 1:

    The City Sector Model is applied to the 52 major metropolitan areas in the United States (over 1 million population). The metropolitan areas are broken into principal urban areas, with all other areas considered to be exurban. The principal urban areas also include the Concord urban area and the Mission Viejo urban area, which are adjacent to and included in the San Francisco and Los Angeles urban areas respectively. As a result, some smaller urban areas, such as Palm Springs (Riverside-San Bernardino metropolitan area), Lancaster (Los Angeles metropolitan area) and Poughkeepsie (New York metropolitan area) are considered exurban. Areas with less than 250 residents per square mile (100 per square kilometer) are also considered exurban, principally for classification of large areas on the urban fringe that have a substantial rural element.

    The Pre-Auto Urban Core includes all non-– exurban areas in which is the median house (single-family or multi-family) was built is 1945 or before. Three density levels were considered, 10,000, 7,500 and 5,000 per square mile (4,000, 2,900 and 2,000 per square kilometer). The lower 5,000 per square mile was examined to test the extent to which such a low density would increase the urban core population. This density, less than the entire urban area (urban core and suburban) of the Los Angeles, San Francisco, San Jose and New York urban areas would have, at the most raised the urban core population to 21.5 percent of the metropolitan population, even with a modest 10 percent transit, walking and cycling market share (Figure 8)

    The pre-auto urban core specification results in a 2010 population for the metropolitan areas with Pre-war and non-suburban historical core municipalities within one percentage point of the actual total, excluding the far higher density case of New York.

    The analysis showed that a lower transit, walking and cycling market share at a 7,500 per square mile floor (2,900 per square kilometer) would substantially increase the Pre-Auto Urban Core category population, while diluting its urban core nature. More than one-half of the increase would be in Los Angeles which has added literally millions of residents in high density suburban areas that are as automobile oriented as suburbs elsewhere.

    The analysis zones (zip codes) have an average population of 19,000, with from as many as 1,000 zones in New York to 50 in Raleigh.

    Note 2:

    An approximation based on the Gordon and Janzen approach would indicate an urban core population of only 8 percent in the major metropolitan areas of the United States. This approximation results in a modeled population for the metropolitan areas with pre-war and non-suburban historical core municipalities of less than one-half the actual 2010 population.

    This Queen’s University research comparison in Figure 8 is referred to as an approximation, since it applies an overall transit, walking, and cycling market share for the six major metropolitan areas, instead of a factor corresponding to each metropolitan area (the Gordon and Janzen approach).

    The differences in transit market share relative to the US are substantial. This may be best shown by considering Calgary, which with a population of 1.2 million in 2011 would have ranked as the 47th largest metropolitan area if it were in the United States. Yet, Calgary would rank second only to the New York metropolitan area in transit market share if it were in the United States. Even so, Calgary is found to be the most suburban of Canada’s major metropolitan areas in the Queen’s University research and Statistics Canada data from 2011 indicates strong domination of urban travel by the automobile.

    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.

    Photo: Los Angeles