2006 Pisarski Report on Commuting in America

1. PART 1 UNDERSTANDING COMMUTING PATTERNS AND TRENDS
Introduction 1
The Commuting in America series has been con- A new story emerging today is that of the
cerned with describing the travel of workers between immigrant populations that arrived in extraordinary
their homes and workplaces. To ensure complete- numbers in the 1980s and even more dramatically in
ness, working at home is included as part of the the 1990s. They already have had, and will continue
picture. In technical literature, commuting has to have, a strong influence on the nature and charac-
been called the journey to work and does not include ter of American commuting. Immigrant populations
trips conducted as part of work activities such as a will constitute a substantial share of our population
bus driver’s work day or an executive’s business trip growth in the future and an even more significant
to attend a meeting. A world of complexity grows part of the working-age population.
from this seemingly simple picture. What mode of Part of the challenge is separating these two
transportation did commuters use? Did they use stories—one nascent, one in its closing stages—and
more than one? Is it a constant pattern or does it recognizing their very separate and distinct charac-
vary occasionally? What about workers with no fixed ters are intricately interwoven to create the overall
place of work, such as construction workers? What patterns of contemporary commuting.
about workers with more than one job—or with a Almost 20 years ago, the first report in the Com-
part-time job? All of these elements introduce some muting in America series talked about the need to
complexity into a straightforward understanding and replace old images of commuting with a more valid
produce some degree of fascination. Transportation picture. The images derived from the 1950s and
can be described as the interaction of demography 1960s often involved a suburban worker leaving a
with geography. This is certainly true of commuting. dormitory-like suburban neighborhood to go off to
The demographic forces at sway in the society define a “downtown” job location. This is still a significant
a great deal of the way in which workers choose to pattern in 2005, but it ceased to be the dominant
live and work and how they move across the land- part of the statistical picture in the 1980s, although
scape from their homes to workplaces. its influence remains strong in a policy sense and in
Part of the story to be told by this study will be terms of infrastructure requirements. That old image
the extraordinary rise and fall of the baby boom has been replaced with one more consistent with
generation’s entry into the commuting workforce. the realities of contemporary commuting attributes.
Commuting in America II made the point that the This new understanding of commuting has three
1990 census might have documented the high parts: a boom in workers, often from two-worker
point of both the population and worker growth households; a boom in suburb-to-suburb com-
period and signaled the closing of the worker boom. muting, becoming the dominant flow pattern; and
That expectation seems to have been confirmed by a boom in the use of private vehicles as America’s
the 2000 census, but not always in ways that were vehicle fleet exceeded the number of drivers. This
expected. Just as the baby boomers had enormous study will examine whether those three themes con-
impact on elementary schools, secondary schools, tinue to be valid.
and colleges in the 1950s, 1960s, and into the 1970s, It is clear that the awareness of this shift to a
they had massive effects on the commuting popula- suburban-dominant commuting pattern is now
tion and the nation’s transportation systems from part of the accepted public knowledge, although it
the 1970s onward to today and into the immediate is surprising how often people are still taken aback
future. In 2010, when the first of the baby boomers to learn this. Its impact on land-use patterns, urban
born after World War II reaches 65, the themes of form, and the society in general has been discussed
the working and commuting story will change again. extensively in policy literature and the public press.
One of the keys to the future will be how this large The questions then become: Are the patterns observed
segment of the population approaches retirement.
Already, there are indications that the baby boomer
approach to retirement will be very different from
that of recent generations.
C O M M U T I N G I N A M E R I C A III |1

2. in the 1980s and 1990s still effective descriptors of
FIGURE 1-1 A Taxonomy of Travel
contemporary patterns of commuting? and What new
patterns are emerging? 1
To/from work
Gaining a sound perspective on commuters and Commuting
commuting requires a mix of disciplines—demo- Work-related business
graphics, economics, geography, and other skills— School
crucial to understanding the nature of this subject. Personal business
2
Commuting is a social, economic, and technological Other resident Shopping
travel Visit friends and relatives
phenomenon. It strongly influences both private and Social/recreational
Although public investment decisions. Each of these facets of Medical/dental
commuting often
the topic plays out in ways that are endlessly fasci- Other
nating. Understanding these influences and their
dominates public interactions with the other influences acting in 3 Overnight visitors
society today has been the express goal of this study. Visitor travel Same-day visitors
discussion about Business travel
transportation,
Government/military
it is crucial to COMMUTING AND OVERALL TRAVEL Police
4
recognize that it One image from the 1950s and 1960s that needs to Public vehicle Fire
be dispelled is that the work trip is what passenger travel Ambulance/emergency
is just part of the Refuse
travel is all about. The journey to work is only one Road construction/maintenance
demands that of a large number of purposes that generate daily
we make on our travel activity. In 1956, the landmark metropolitan Couriers
transportation transportation study that ushered in the modern era Store delivery
5
of transportation studies, the Chicago Area Trans- Urban goods Home delivery
systems. portation Study (CATS), identified about two trips and services Office delivery
travel Factory delivery
per day per capita, of which approximately 40% Services/repair
were work trips.1 Today, total travel has risen to Construction
more than four trips per day per capita, and work
travel is well below 20%. Telephone
Commuting exists in a continuum of transporta- 6 Gas
Utility services Electric
tion activities. Although commuting often domi- travel Water
nates public discussion about transportation, it is Cable TV
crucial to recognize that this is just one demand that
we make on our transportation systems. There are 7 Business
Passenger Social/recreational
eight categories of activities, as follows, in a metro- through-travel
politan transportation system: Visit friends/relatives
■ Commuting, 8 Agriculture/forestry
■ Other resident travel, Freight Construction/manufacturing
■ Visitor travel, through-travel Wholesale/retail
Import/export
■ Public vehicle travel,
■ Urban goods and services travel,
■ Utility services travel, pressure for transportation data collection and com-
■ Passenger through-travel, and prehensive planning at the state and metropolitan
■ Freight through-travel. levels, there is probably no state or metropolitan area
It is not feasible to describe the share of this total in the country that can comprehensively describe the
activity represented by commuting because of the activity levels of all eight of these elements of travel
mix of freight, services, and passenger activities. in their area. (This statement was originally made in
There are no comprehensive data sources of freight Commuting in America II and there does not seem
movements or visitor travel from which such a pic- to be any reason to revise it.) We do know that, in
ture could be constructed. Clearly, the mix of these most places, trucking continues to grow more rap-
eight elements, identified in Figure 1-1, will vary idly than passenger travel. Trucking on some routes
with area size and the nature of activity in the met-
ropolitan complex. Despite 50 years of congressional
1
Chicago Area Transportation Study (CATS) 1956 base year
statistics, CATS, Vol.1.
2 | C OMMUTING IN AMERICA III

3. could account for more than 25% of road volumes. Work travel is most often measured as a pro- Work travel now
The prodigious growth rates in freight travel across portion of person trips, as in the first column in only constitutes
the Mexican and Canadian borders spurred by the Table 1-1, or as a proportion of person miles of
North American Free Trade Agreement (NAFTA) travel, which weights the trip shares by their aver- about 16% of
are illustrative; freight flows increased more than age distances. As work trips tend to be longer than travel but that is
11% by value on surface modes in 2004. We know most other local trips, the work trip share of travel is attributable to
that long-distance travel—intercity travel for both greater than its share of trips, as shown in the second
business and pleasure—has regained the levels and column of Table 1-1. the dramatic
growth rates prior to 9/11. Previous estimates indi- When these activities are looked at on a modal growth in other
cated that intercity passenger travel could constitute level, the role of work travel expands. Work travel activities rather
as much as 25% of total passenger miles of travel by plays a far more significant role in public transporta-
all modes.2 tion than in transportation by private vehicle. For than diminished
We can place commuting in context with local public transportation, 35% of all trips made on work travel.
metropolitan passenger travel by residents if we look
at the shares of total travel by the different purposes TABLE 1-1 Travel Shares by Purpose, 2001
for travel, in effect focusing only on two categories
of transportation activities—commuting and other Trip purpose Person trips (%) Person miles of travel (%)
resident travel. It is helpful that the Nationwide To/from work 14.9 18.1
Personal Transportation Survey (NPTS), renamed the Work-related business 2.9 8.1
National Household Travel Survey (NHTS) and con-
Shopping 19.8 14.0
ducted in 2001 before reverting to its original name,
covers roughly the same time period as the census. Family/personal business 22.5 17.3
This permits consistent analysis of commuting in School/church 9.8 5.9
the context of other passenger travel demand. The Medical/dental 2.2 2.3
NHTS indicates that work travel constitutes roughly
15% of all person trips, as seen in the first column Vacation 0.6 2.7
of Table 1-1, indicating a significant decline in share Visit friends/relatives 7.9 11.6
from the 20% observed in 1990. (The fully compa- Other social/recreational 18.4 16.2
rable number between the surveys is more like 16%,
Other 0.9 3.8
however, because the 2001 survey, for the first time,
separately identified trips made by children under All 100.0 100.0
5 years of age; even when the child usually is accom- Source: NHTS 2001
panied by an adult, the trip is counted as part of
total household travel activity.) The decline in share
is not so much due to any decline in work travel but FIGURE 1-2 Daily Trips per Capita
rather to a more rapid growth in other trip pur-
poses. In the period from 1977-2001, work trips per 2.5
capita rose 14% while personal business travel rose
114%, social/recreational travel rose 65%, and even 2.0
school travel rose 27%, as is discernible from Figure
Person trips
1-2. Absolute changes in work trips per capita can 1.5
derive from changes in the frequency of work trips 1.0
of workers or a shift in the proportion of workers in
the population. Rising incomes are a major factor 0.5
here. As incomes rise, total trip-making increases, but
certain trip purposes rise faster than others. Figure 0.0
1975 1980 1985 1990 1995 2000 2005
1-3 shows that as incomes rise work trip growth
shows significant increases in the lower brackets but
levels off at middle levels, as might be expected. The Work Family/personal business
big rises in personal business travel and social/recre- School/church Social/recreational
ational travel help to explain the high growth rates Other
for these purposes observed in the previous figure. A
new, and close to exhaustive, list of 36 trip purposes
used in the 2001 NHTS is shown in Table 1-2.
2
American Travel Survey, Bureau of Transportation Statistics, US
DOT, Washington, D.C., 1995.
C OMMUT I NG I N A ME R I CA III |3

4. FIGURE 1-3 Person Trip Rates by Purpose and Income
1.2
1
0.8
Trips per day
0.6
0.4
0.2
0
Visit friends/
business
Shopping
Family/personal
business
School/church
Medical/dental
relatives
Other social/
Work-related
Vacation
To/from work
recreational
< $20,000 $20,000-$35,000 $35,000-$50,000 $50,000-$75,000 $75,000+
tics) and 49% of passenger miles of travel (PMT) are
FIGURE 1-4 Work as a Percentage of All Travel Measures
accounted for by work trips. Among private vehicle
trips for a driver, work trips account for only about
40 22% of all trips and about 27% of vehicle miles of
travel (VMT).
35 The trend for work trips over the years has exhib-
30 ited a significant declining share of overall travel by
almost any measure, as shown in Figure 1-4. This
25 should not mislead. Work trips per worker have
remained roughly constant between 1990 and 2000
Percent
20 according to the NHTS, so, total increases in work
15 trips are only a product of the growth in the number
of workers. But all other trip-making purposes have
10 grown more rapidly.
Commuting bears an importance to transporta-
5 tion beyond its share of total travel for the following
0
reasons:
1965 1970 1975 1980 1985 1990 1995 2000 2005 ■ The impact of commuting on the economy, and
even on the development structure of communities,
Person trips Person miles of travel
is significant. Communities and larger government
Vehicle trips Vehicle miles of travel
entities will often seek to attract jobs and workers
Note: No data available prior to 1969. in particular occupations and industries for their
tax revenue or other benefits. Often, the commut-
ing patterns that result are the product of these
transit (defined by the NHTS set of alternatives as
decisions. Although work trips have just been cited
local public transit bus, commuter bus, commuter
as being about 15% of all travel, when trips made
rail, subway/elevated rail, and street car/trolley; other
during the day from work (work-connected busi-
modes include limited numbers of what could be
ness, 2.9%; and personal travel from work, 2.3%)
called “transit” trips to work, such as intercity bus
and trips made on the way to and from work
and rail, but their use here would distort the statis-
(accounting for approximately 5% to 6% of travel)
are aggregated, the share of total travel is on the
order of 25% to 26% of all travel. Thus, the
home–work axis is an important definer of travel.
4 | C OMMUTIN G IN AM E RICA III

5. TABLE 1-2 Detailed NHTS Day-Trip Travel Purpose Codes
Number Code Description Number Code Description
1. To Home. Travel to home after leaving for some reason. 19. Go Out/Hang Out. Entertainment/theatre/sports event.
2. Go To Work. The first trip to the work location on travel day. 20. Visit Public Place. Historical site/museum/park/library.
Social/Recreational. Includes social and recreational trips not covered by
3. Return To Work. A trip to work that is not the first trip to work on the travel day. 21. Categories 16 through 20 above.
Attend Business Meeting/Trip. A work-related trip whose purpose is to attend a Use Professional Services, Attorney/Accountant. A trip made for professional
4. 22.
business meeting. services other than for medical/dental purposes.
Other Work Related. A work-related trip whose purpose is not specifically to
5. 23. Attend Funeral/Wedding. A personal trip to attend a funeral or a wedding.
attend a business meeting.
Use Personal Services. Grooming/Haircut/Nails. A trip for personal services
6. Go To School as a Student. A trip whose purpose is to go to school as a student. 24. such as to a hairdresser.
Go To Religious Activity. A trip whose purpose is to go to a place to attend a
7. 25. Pet Care. Walk the dog/vet visits.
religious activity.
Go To Library, School Related. A trip whose purpose is to go to the library as Attend Meeting, PTA/Homeowners Association/Local Government. The
8. 26. purpose of the trip is to attend a non-work-related meeting, such as a com-
part of a school-related activity. munity meeting.
Family Personal Business/Obligations. A trip for personal business not covered
9. Go To Day Care. A trip whose purpose is to attend day care. 27. by Categories 22 through 26 above.
Other School/Religious Activity. School and religious activities not covered by
10. 28. Pick Up Someone.
Categories 6 through 8 above.
Medical/Dental Services. A trip made for medical, dental, or mental health
11. 29. Take Someone and Wait.
treatment, or other related professional services.
Buy Goods (e.g., groceries/clothing/hardware store). A shopping trip whose pur-
12. pose is to purchase commodities for use or consumption elsewhere. This purpose 30. Drop Someone Off.
also includes window shopping and trip made to shop even if nothing is purchased.
Buy Services (e.g., video rentals/dry cleaning/post office/car service/bank). Transport Someone. Trips with a passenger that are related to picking up or
13. The category includes the purchase of services other than medical/dental or 31. dropping off someone but not covered by Categories 28 through 30.
other professional services.
14. Buy Gas. A trip made specifically to buy gas. 32. Social Event. A trip whose purpose is to eat a meal at a social event.
Shopping/Errands. Shopping errands not covered by Categories 12 through 14 Get/Eat a Meal. A trip whose purpose is to get and eat a meal but not at a
15. 33.
above. social event.
Go To the Gym/Exercise/Play Sports. A trip made for exercise or to participate Coffee/Ice Cream/Snacks. A trip whose purpose is to get/eat a snack or
16. 34.
in a sport. drink, something less than a meal.
Meals. A trip whose purpose is to eat or get a meal but not covered by
17. Rest or Relaxation/Vacation. 35. Categories 32 through 34 above.
Visit Friends/Relatives. The social/recreational trip whose purpose is to visit
18. 36. Other. A trip purpose not covered by Categories 1 through 35 above.
with family and friends.
Source: “2001 National Household Travel Survey,” Data Dictionary, FHWA.
■ Commuting is one of the few trips, along with 20% on most work days, dropping on Fridays as Commuting is the
school travel, that is regular in its frequency, work trips decrease in number and trips for other major factor in
time of departure, and destination (in the nature purposes increase.
of a daily appointment). Therefore, delays—par- ■ The focus on work travel is due to the concentra- determining peak
ticularly recurring delays—generate a recogni- tion of work travel in specific times and loca- travel demand
tion and far more intense reaction than do other tions, in contrast to the typically more dispersed and therefore
trips. It is very often the longest trip of the day patterns of other trips with respect to both time
for many people. It is the trip where reliability and space. Commuting is a major factor in serves to define
of travel time really matters. It is the trip that determining peak travel demand and therefore the high-cost peak
people complain about. Figure 1-5 shows that, serves to define the high-cost peak capacity and capacity and ser-
not surprisingly, work travel is concentrated dur- service requirements of our transportation systems
ing the work week, and on average constitutes far more than other purposes of travel. There are vice requirements
about 18.4% of travel on weekdays, contrasted indications that in certain climates and weather of our transporta-
to the 14.9% averaged over 7 days. It is closer to conditions, morning travel is more critical to air tion systems far
pollution generation, particularly ozone. But even
in the peak periods, the influence of other trip more than other
purposes is strongly felt. travel purposes.
C O M M U T I N G I N A M E R I C A III |5

6. Almost exactly two-thirds of all trips to work
FIGURE 1-5 Trip Distribution by Day of Week
occur between 6-9 a.m., based on the 2000 census
a. trip purpose observations, causing substantial stress on the trans-
portation system. Further, work and work-related
70,000
travel account for more than one-third of all person
trips and almost half of all person travel in the same
60,000 6-9 a.m. period. One of the extraordinary findings
of the NHTS is that between 5-6 p.m. about 30%
50,000 of the population, almost 90 million people, are in
Annual trips (millions)
motion.
40,000 As discussed later in Part 3, both the morning
and evening peaking characteristics of work travel
30,000 seem to be dispersing both in location and time.
There are indications in the NHTS data and the
20,000 patterns discernible from the census that, perhaps
as a product of work arrangement shifts or conges-
10,000 tion pressures, the proportion of work travel in the
peak hours is declining and spreading over into
0 other time periods. Those traveling to work in the
Monday
Sunday
Wednesday
Friday
Tuesday
Saturday
Thursday
6-9 a.m. period have grown substantially in numbers
but declined as a share of work travel from the 69%
observed in 1990. Most of the shift has been to the
Other Medical/dental Shopping 5-6 a.m. time period. A simple way to express this is
Other social/recreational School/church Work related that the peak “hour” today is a peak period extend-
Visit friends/relatives Family/personal Work ing over large parts of the day. The spatial dispersion
Vacation of work trip origins and destinations is a fundamen-
tal aspect of contemporary work travel.
Beyond this very sound basis for a consider-
b. work trip share able level of interest in work trips, there are several
25 broader points to consider. Workers themselves are
18.9% 19.3% 18.7% 18.8% 18.4% the major part of the population and their travel
20
16.5% activities constitute the major part of all travel.
14.9%
15 Much of that travel is wrapped around, intertwined
Percent
with, or otherwise affected by their work travel
10
6.4% activities, whether the location, route, time, or mode
4.7%
5 of travel. If all trips by workers, not just their work
trips, are considered, workers account for 77% of all
0 local travel in the 6-9 a.m. period, whether mea-
7-day
Sunday
Friday
5-day
Saturday
Wednesday
Monday
Thursday
Tuesday
sured by trips or miles of travel. In short, the work
trip helps define a very large part of all travel.
The 2001 NHTS results indicate that in their
survey about 75% of the population was 16 or more
TABLE 1-3 Workers’ Share of Total Travel years of age and 70% of those were workers. While,
therefore, just above half of the population, workers
Workers
account for about two-thirds of all of the nation’s
Attribute % of All Population % of Population Age 16+ daily passenger travel and 82% of the vehicle miles
Population 52.41 69.79 of travel. It is not their work trips that cause this
Trip makers 55.57 73.57 substantial difference as much as all of the other
trips and activities engaged in by the working popu-
Person trips 58.63 74.12
lation—on the way to and from work, caring for
Vehicle trips 77.15 78.31
PMT 66.24 79.03
VMT 82.10 83.22
PMT in private vehicle 58.57 77.77
Sum of daily travel time 60.03 74.28
6 | C OMMUTIN G IN AM E RICA III

7. Workers are the
FIGURE 1-6 Travel Shares by Hour of the Day
major part of the
400 population and
Nonworker Worker
their travel activities
300
constitute the major
Thousands
part of all travel.
200
Much of that travel
100 is wrapped around,
intertwined with, or
0 otherwise affected
12 A.M.
8 A.M.
1 A.M.
2 A.M.
4 A.M.
9 A.M.
10 A.M.
3 A.M.
5 A.M.
6 A.M.
11 A.M.
7 A.M.
12 P.M.
1 P.M.
2 P.M.
4 P.M.
3 P.M.
5 P.M.
6 P.M.
8 P.M.
7 P.M.
9 P.M.
10 P.M.
11 P.M.
by their work travel
activities, whether
the location, route,
FIGURE 1-7 Trip Chain Conceptual Layout
time, or mode
of travel.
DAY
CARE
Trips to work with
HOME DIRECT WORK TRIP WORK stops are increas-
ing, both in number
of workers making
DAY
SHOPPING stops and number of
CARE
stops per worker.
The “trip chain”
increases the
their families, etc. This is sharply demonstrated by ■ Persons with stops take longer in miles and min- efficiency of overall
Figure 1-6. Note also in Table 1-3 that workers are utes than those with no stops; travel but also has
over 55% of the trip makers and incur 60% of the ■ People who make stops tend to be those living a the effect of increas-
daily travel time in the nation. greater distance from work;
Other aspects of commuting are changing in ■ Suburbanites make more stops than urban ing the number of
ways that affect other parts of travel and the trans- dwellers; trips that are not
portation system serving it. One of these is the ■ Stops are increasing for men as well as women; work-related but
increased tendency for commuters to make their ■ Women still make the greater number of stops in
work trip as part of a trip chain, dropping off both the work and home directions; occur in the peak
children, picking up necessities, and conducting ■ The greatest increase has been by men in the period.
household chores as part of an effort to use time work-bound direction, often just for coffee (the
efficiently, as depicted in Figure 1-7. This is largely a Starbucks effect3); and
product of the immense time pressures on workers, ■ Use of nonvehicular modes drops sharply among
especially working women. General attributes of those with stops.
the work trip chain are as follows:
Such a pattern increases the efficiency of over-
■ Trips to work with stops are increasing, both in all travel but also has the effect of increasing the
number of workers making stops and number of number of trips that are not work-related but occur
stops per worker; in the peak period. It also can militate against the
■ Persons with stops take longer in miles and min- use of carpooling or transit modes. In contrast to
utes than they did in 1995; making individual trips, the work trip chain offers
private vehicle users the benefit of fuel savings from
3
Nancy McGuckin of NHTS, 2005.
COMMUTING IN AMERICA III |7

8. reduced travel, pollution savings from fewer “cold particular strengths and weaknesses for our purposes.
starts” (i.e., catalytic converters are more effective The final discussion in Part 1 focuses on the difficult
once warmed up), and time savings. topic of geography. Because of its spatial character,
commuting analysis is especially sensitive to the
geographic units used to aggregate and present data.
STUDY STRUCTURE This is particularly a concern in national analyses
Commuting in America III is divided into four parts. where comparability between areas is crucial. The
Part 1, Understanding Commuting Patterns and Census Bureau has modified its geographic terms
Trends, introduces the subject of commuting by and definitions. This impedes the ability to compare
addressing the conceptual and practical problems of changes—are they real or definitional?
understanding commuters and commuting, given Part 2, Commuters in the Nineties, addresses
the complexities of the subject and the vagaries of aspects of commuters and their characteristics.
the available data. The first objective of this section Discussed are the changing characteristics of the
is to place commuting activity in its proper context nation’s population, its households, and workforce,
with the rest of transportation so the role of com- as it traces the aging baby boomers’ flow through the
muting in the overall structure of transportation workforce years and the prospects for a new work-
planning and policy is understood. Also reviewed force to support their retirement. A continuing topic
is some of the background information and special is the size of the role immigration plays in the new
terminology required to understand commuting as workforce. Also examined is where the workforce
described in this study. This includes a brief identi- lives and works, how these locations have changed,
fication and description of the attributes of the spe- and what the growth rates have been with respect
cific data sources used in the study, including their to metropolitan areas and states. The “demography”
FIGURE 1-8 Census Regions and Divisions
DIVISION 4 | WEST NORTH CENTRAL DIVISION 1 | NEW ENGLAND
Iowa Missouri
PACIFIC
Connecticut New Hampshire
Kansas Nebraska Maine Rhode Island
Minnesota North Dakota 0 200 400 Miles
Massachusetts Vermont
South Dakota WEST
MIDWEST
DIVISION 2 | MIDDLE ATLANTIC
DIVISION 9 | PACIFIC RTH
E AST New Jersey
NO
Alaska New York
California Pennsylvania
Hawaii
Oregon DIVISION 3 | EAST NORTH CENTRAL
Washington
Indiana Ohio
Illinois Wisconsin
DIVISION 8 | MOUNTAIN Michigan
Arizona Montana REGION
DIVISION
Colorado Utah 0 200 400 Miles
STATE
DIVISION 5 | SOUTH ATLANTIC
Idaho Nevada PACIFIC
SOUTH Delaware North Carolina
New Mexico Wyoming HI
0 100 200 Miles
District of Columbia South Carolina
Florida Virginia
DIVISION 7 | WEST SOUTH CENTRAL Georgia West Virginia
Arkansas Maryland
Louisiana
Oklahoma DIVISION 6 | EAST SOUTH CENTRAL
Texas Alabama
Kentucky
Mississippi
Source: U.S. Department of Commerce, Economics and Statistics Administration, U.S. Census Bureau.
Tennessee
8 | C OMMUTIN G IN AM E RICA III

9. of the personal vehicle is investigated as well, by shown in Figure 1-8, figure prominently in that dis-
assessing the characteristics of the immense fleet of cussion. We are witnessing major changes from one
vehicles available to all households, and especially to region to another. Part 3 also addresses the popular
working households. A key aspect of understanding topics of travel time trends and congestion. Since the
commuting is addressed in the examination of the dataset’s initiation in 1990, the 2000 census provides
ownership distribution of vehicles among age groups the first update on the times workers leave home
and, particularly, among racial and ethnic groups. each day to start their journeys to work. These data
Those households without vehicles are a central provide the first occasion to measure how commuters
focus of concern. Are they growing again after liter- have adjusted their schedules, shifting away from
ally a century of reductions? “peak hours” as job patterns change or in order to
Part 3, Commuting in the Nineties, looks at avoid congestion. Part 3 concludes with a brief treat-
detailed commuting flow patterns and their changing ment of aspects of direct commuting costs.
scale and scope. Commuting patterns are examined Part 4, Closing Perspectives, examines the direc-
from the perspective of the flows of commuters tion that national public data provision for studying
between central cities, suburbs, and nonmetropoli- commuting and meeting local planning and policy
tan areas. Commuters and commuting activity are needs will tend toward in the future. It considers the
described from three vantage points: the origins effects of the expected loss of the decennial census
of work trips, usually the home end of the daily long form as the fundamental source of commuting
journey; the destination ends, which are the job data, assesses the prospective role—the strengths and
sites; and the patterns formed by the flows between weaknesses—of the new annual American Commu-
the multitude of origins and destinations. Each has nity Survey (ACS), and discusses what this change
important insights to provide and interesting facets will mean for national, state, and local transporta-
that can add to our understanding. An intensive tion analysis capabilities. What opportunities does
look at population densities at which people live and the new survey system promise? What challenges
work is provided. will it present?
A broad treatment of the commuting picture The report concludes with a brief look at the
throughout the country is presented. Groupings implications of the changes examined in the previ-
of these flows by type and scale are looked upon ous materials in terms of their impacts on the com-
as “markets” for meeting the needs of commuting muter and commuting, the infrastructure that serves
demand. The nature of so-called “commuting bal- commuting travel, and the broader community.
ance” will be addressed using many of the same With the goal of encouraging further discussion and
measures that the Office of Management and Budget analysis of this important topic, this section provides
(OMB), the agency responsible for defining metro- the author’s sense of what the data tell us, the mean-
politan areas and their elements, employs to define ing of the trends identified, and their implications
metropolitan areas. Do we have a new suburban for the future of commuting. The appendices that
phenomenon of balanced communities more like follow provide a glossary of terms and important
the 1960s or 1980s? A key question addressed is, reference materials such as the actual Census Bureau
Are jobs and workers getting more concentrated or more survey questions and the Census Transportation
dispersed? New consideration of flows to downtowns, Planning Package tabulations from which much of
sometimes called central business districts in the past, the data to create the Commuting in America series
are examined in detail. Concerns about congestion have been derived.
have tended to sharpen interest in major metropol-
itan areas but rural commuting issues need discussing
as well. A major focus of this part is contained in two
extensive chapters that address the modes of trans-
portation employed in the different markets for work
travel. Also examined is the new variability in mode
choice versus the continuation of past trends. Where
might we expect to see a resurgence in alternatives
to the single-occupant vehicle? What are the varying
levels of modal usage among significant socioeco-
nomic groups? The regions of the United States,
C O M M U T I N G I N A M E R I C A III |9

10. 2 Background
The discussion of commuting requires intensive use DATA SOURCES
of available data sources. Since the field is not rich The fundamental information sources for this
in sound, comprehensive data sources, this chapter undertaking are the data on the journey to work
introduces some of the major data sources and their and related characteristics from the 2000 decennial
attributes, including strengths and weaknesses, to help census and its predecessor long-form surveys in the
readers appreciate some of the gaps. It also addresses the 1990, 1980, 1970, and 1960 decennial censuses.
question of how these data are represented geographi- These are the sole nationwide detailed, geographi-
cally, one of the critical elements of understanding. cally comprehensive sources of data on commuting
Much of travel can be explained as the intersection of patterns. Their greatest strengths are the uniformity
demography with geography. A better acquaintance of the data collected nationwide, and the wealth of
with the two forces acting on commuting will make demographic information associated with the work
subsequent chapters a little easier to digest. travel information consistent with most of the other
Over the years, the transportation profession national sources. All credible national evaluations of
has developed a shorthand of terms and a jargon commuting must start here. The data have improved
to make its work easier, but this does not make the at each census and have become a rich source of
work more accessible to the average reader. To help fundamental work travel characteristics, including
the reader get through the thicket of special terms, information on vehicles available, choice of mode
Appendix 1 provides a brief glossary containing of travel to work, detailed residence and workplace
most of the terms that appear in this report, with geography and associated socioeconomic descriptors
definitions designed to be an aid to understanding of the traveler and the traveler’s household. Without
rather than a rigorous, definitive delineation of the this source, this analysis would not be possible.
term. Formal definitions of census and transporta- This study uses the census data directly from the
tion terms can be found in special guides prepared Census Bureau sources in printed and computer-
by the Census Bureau and the US DOT Bureau of based form, and indirectly from data files produced
Transportation Statistics, respectively. by the Census4 and the US DOT to summarize
Two other introductory matters are important to national trends. The Census Bureau has made
our understanding of the commuter and commut- tremendous strides in improving access to the data
ing. The first is the source or sources of information emanating from censuses. The American FactFinder
that support this study—the statistics needed to webpage available on the Census website can provide
fully understand the complex character of commut- quite extensive information in seconds—a task that
ing. The data needs are great: comprehensive infor- used to take weeks or months. In addition, such new
mation, rich in detail, with broad national coverage, technologies as representative sample records arrayed
comparable through time to permit identification on a CD with built-in retrieval software provide
and analysis of trends. dramatically improved statistical capability.
The second is the geographic descriptors needed A key concern of this undertaking has been the
to assemble and present statistics. First and foremost, ability to describe the trends in commuting over the
commuting is a spatial phenomenon and the geo- long term. Although the Census data have changed
graphic units selected to aggregate individual trips are over time, they have always retained definitional com-
the key to correctly representing its character. Each of parability from census to census. Thus, it is possible
these facets of the geographic descriptive structure are to make meaningful comparisons over the 40 years
discussed below to assist the reader in understanding that the Census Bureau has considered the question
what some of the conventions and definitions used in of commuting. In some cases, geographic definitions
this document mean and how they affect the ability have to be restructured to assure comparability.
to understand the commuting phenomenon.
4
A convention is adopted here: census, lower case, refers to the
activity of counting, Census, upper case, is a shortened reference to
the agency itself—the Census Bureau.
10 | COMMUTING IN AMERICA III

11. The work-related travel questions, part of the so- separately identified trucks and vans. Any such addi-
called long form, are asked of approximately 17% of tions must always be balanced against the intrusion of
all U.S. households as an addition to the very basic asking a question of approximately 50 million people.
set of questions mandated by the Constitution. The The support these data provide for national-
long-form questions are necessarily limited, given scale documents such as this one are a very useful,
the competition for question space in the multi- but actually minor, function of the Census Bureau’s
billion-dollar census long form, which seeks to meet journey-to-work dataset. The main strength of
many national statistical needs, including appor- the dataset is that it provides small-area statistics
tionment of the seats in the House of Representa- for every segment of the nation, down to units of
tives. The transportation question set represents a geography measured in neighborhoods and even
minimum dataset, particularly for those accustomed blocks, to support local planning and analysis. While
to the richer information derived from traditional a broad national sample would probably be adequate
urban transportation surveys. The actual journey-to- for producing Commuting in America, small-area sta-
work questions from Census 2000 are reproduced in tistics are irreplaceable for local planning. In 1990,
Appendix 2. It is important to recognize that every and again in 2000, these data have been specially
question included in the census must be justified to produced in a large-scale package of tabulations,
the President’s Office of Management and Budget. called the Census Transportation Planning Package
This justification must be based on direct congres- (CTPP), to meet both state and metropolitan needs.
sionally mandated purposes, or purposes directly The development of these data products were orga-
associated with meeting legislatively mandated func- nized and funded by AASHTO. These data, pro-
tions. The census journey-to-work data are therefore duced at a very fine level of detail that includes small
something of a compromise. Their quality and scale traffic zones, permit the kind of detailed analyses
of coverage are unequaled, but they provide less required in our contemporary policy framework for
detail than we frequently would wish to have about transportation planning, energy, and air quality
the specifics of commuting travel. Among the sig- evaluations. The national-level tabulations produced
nificant gaps in the dataset are the following: for this report by the Census Bureau represent the
national summary portion of the CTPP package. See
■ No information is obtained about aspects of trips
Appendix 3 for the complete listing of the CTPP
using more than one mode of travel to get to work.
tabulations in summary form.
■ No information is obtained about the patterns of
Although the decennial census is the primary
second-job travel from those with more than one job.
and fundamental source of the data that produces
■ No information is obtained about variations in
this document, other datasets have been used where
“usual” travel patterns, such as for those who work
possible to fill out the overall picture. Among these
at home occasionally.
datasets, second only to the decennial census is the
■ No information is obtained about other trips
material from the NHTS, conducted by the US
linked to the work trip in a “trip chain” on the
DOT in 1969, 1977, 1983, 1990 (coincident with
way to or from work (e.g., dropping off children
the census), 1995, and 2001. The great value of the
at school, picking up laundry, food, etc.).
NHTS is that it is strong precisely where the census is
■ The census reports on activity in one week in
weak. It offers the linkage to other trip activity as pre-
April, ostensibly, with no seasonal balance.
sented just above, provides work-trip distances and
■ The census findings on the number of workers do
speeds, and addresses the multimodal trip question as
not always agree with other surveys that identify
well as the multi-job and part-time job worker. The
workers and the labor force. These issues are dis-
NHTS also adds very valuable additional material
cussed in Parts 2, 3, and 4.
on vehicles and their owners. All of this material is
Despite these caveats, the data available are a very examined later in Parts 2 and 3.
rich source of fundamental work travel characteristics The American Housing Survey (AHS) conducted
nationwide, and the transportation community is by the Department of Housing and Urban Develop-
indebted to the excellent work of the Census Bureau, ment and the Consumer Expenditure Survey (CEX)
and particularly the Journey to Work Division, for of the Bureau of Labor Statistics also have been
the quality of information available. As noted, in used to provide important related measures. These
each census, progress has been made toward a more surveys, both conducted by the Census Bureau,
comprehensive treatment of commuting. In 1980, a provide trend information on such important factors
question on the length of time taken for work trips as housing attributes and vehicle operating costs.
was added, and existing questions on vehicle owner- Other sources of cost information are the Transpor-
ship and the choice of mode to work were expanded. tation Energy Data Book of the Oak Ridge National
In 1990, a question was added about the starting
time of the work trip, and a question was deleted that
C O M M U T I N G I N A M E RI C A III | 11