September 11, 2008
Washington, DC
Demographic Trends Affecting Transportation in the U.S.
Robert Puentes
Realities on the ground have changed dramatically1
Demographic Trends Affecting Transportation in the U.S.
These changes have 3 main spatial effects on the American landscape2Together these patterns have a series of important implications.3
Population Growth Immigration Internal MigrationAging Household Formation
-100,000
0
100,000
200,000
300,000
400,000
500,000
600,000
Nigeria
Pakistan
Philippines
Banglad
eshIndiaBrazil U.S.
Canada
Indonesia
Norway U.K.
FranceChinaSpain
Netherla
ndsKoreaAustria
Denmark Ita
lyGerm
any
Czech
HungaryJap
anPolan
d
-20%
0%
20%
40%
60%
80%
100%
120%
Percent and absolute population growth, 2005-2050
Absolute growth
Percent growth
Source: U.N. Population Division
Unlike most European nations and Japan, the U.S. will continue to grow at a considerable rate.
0
2
4
6
8
10
12
1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 2010 2015 2020 2025 2030 2035 2040 2045
Legal Undocumented
Temprorary (Net) Projected
Total foreign-born, in millions, 1960-2050
Source: Jeffrey S. Passel, 2006
The increase in population will continue to be fueled in part by an enormous wave of immigration.
Mill
ions
Percent growth in U.S. total and senior populations by
decade, 1970–2030
0%
5%
10%
15%
20%
25%
30%
35%
40%
1970-1980 1980-1990 1990-2000 2000-2010 2010-2020 2020-2030
Age 65+ Total
Source: Frey, 2007
This immigration is essential to offset another major demographic trend: the aging of the baby boom generation.
US age distribution, by race, 2020
(Age pyramid moves from the elderly at the top to youths at the bottom)
Source: Census
However, since minorities have younger age structures than whites, the nation’s population pyramids will look quite different.
Male Female
\
Male Female
Male Female Male Female
Whites Hispanics
Blacks API/AI
0
2
4
6
8
10
12
14
1-pers
on household
Single w/ k
idsMarr
ied w
/ kids
Married
no kids
Other family
Nonfamily
Mill
ions
2.0
2.5
3.0
3.5
4.0
4.5
5.0
19001920194019601980200020202040
Household size is declining sharply, primarily due to the increases in single person and parent households.
Sources: (1) Yi, Land, Wang, and Danan; (2) Frey and Berube, 2003 and updated
Persons per household, 1900-2050
Absolute change in households, 1980-2005
U.S. population growth, 1900-2005
Source: Census
0%
5%
10%
15%
20%
25%
30%
35%
40%
1900
1905
1910
1915
1920
1925
1930
1930
1940
1945
1950
1955
1960
1965
1970
1975
1980
1985
1990
1995
2000
2005
2010
2015
2020
2025
South
West
MidwestNortheast
But these growth trends are highly variable across the country. The story of rapid growth in the U.S. is largely confined to the South and the West.
Realities on the ground have changed dramatically1These changes have 3 main spatial effects on the American landscape2Together these patterns have a series of important implications.3
Demographic Trends Affecting Transportation in the U.S.
First, rather than dispersing randomly all this population and economic activity is shifting and re-aggregating within and between major metropolitan areas.
Metropolitan areas have become the engines of national prosperity.
Second, these mega-trends are revaluing the assets of the cities and urban cores within metropolitan areas.
These forces have reconfirmed the primacy and centrality of place.
Third, America's metropolitan areas have become exceedingly complex and have moved well beyond the conventional city versus suburb divide.
These are not your parent’s suburbs
Together these patterns have a series of important implications.3
Demographic Trends Affecting Transportation in the U.S.
3
Realities on the ground have changed dramatically1These changes have 3 main spatial effects on the American landscape2
“Never make predictions, especially about the future.”
-Casey Stengel
Source: Nelson, “Toward a New Metropolis,” 2004
1. What will be the impacts on residential location?
The pressure will be on existing places—especially cities and first suburbs—to accommodate new growth.
Source: NAR, 2004
Exurbs26%
Suburbs20%
Urban Areas54%
Preference for next residential location,
2004
2. How will transportation be impacted by changing household formation?
Demand for higher-density housing in
transit zones could far outstrip the supply
of this kind of housing.
4
6
8
10
12
14
16
2000 2005 2010 2015 2020 2025
Projected Demand: Housing Units in Transit Zones
14.6 million
Source: Center for Transit-Oriented Development, Hidden in Plain Sight and Harvard, State of the Nation’s Housing
3. What will be the impacts of continued diversity?
The nation will be majority minority by 2050 and nearly 90 percent of the population growth in 2050 will be the result of
post 2000 net immigration.
Immigrants are more likely to carpool. But
their high levels of transit use decline over
time.
Blacks and Hispanics together make up nearly half of the
nation’s transit users
0%
10%
20%
30%
40%
50%
Under15
15-24 25-34 35-44 45-54 55-64 65-74 75+
Age Group
4. What will be the impacts of the aging of the population?
Percent of metro residents residing in central cities by age
group, 2000
The location preferences of the elderly do not suggest a “back-to-the-city” movement.
LOSS GAIN
5. What will be the impacts of national migration shifts?
The challenge will be maintaining investments in declining areas without overbuilding.
Projected population change, by county, 2000-2050
Demographics will not be the only determinant of our future, of course. Globalization, climate change, technological innovation, freight, energy concerns, and public policy are key.
Yet we have an enormous opportunity now to shape our nation's metropolitan future.
September 11, 2008
Washington, DC
Demographic Trends Affecting Transportation in the U.S.
Robert Puentes
