1、Brief 10. Commuting Mode Choice OCt Ober 2013 Commuting in America 2013 The National Report on Commuting Patterns and TrendsAbout the AASHTO Census Transportation Planning Products Program Established by the American Association of State Highway and Transportation Officials (AASHTO) and the U.S. Dep
2、artment of Transportation (U.S. DOT), the AASHTO Census Transportation Planning Products Program (CTPP) compiles census data on demographic characteristics, home and work locations, and journey- to-work travel flows to assist with a variety of state, regional, and local transportation policy and pla
3、nning efforts. CTPP also supports corridor and project studies, environmental analyses, and emergency operations management. In 1990, 2000, and again in 2006, AASHTO partnered with all of the states on pooled-fund projects to sup- port the development of special census products and data tabulations
4、for transportation. These census transpor- tation data packages have proved invaluable in understanding characteristics about where people live and work, their journey-to-work commuting patterns, and the modes they use for getting to work. In 2012, the CTPP was established as an ongoing technical se
5、rvice program of AASHTO. CTPP provides a number of primary services: Special Data Tabulation from the U.S. Census BureauCTPP oversees the specification, purchase, and delivery of this special tabulation designed by and for transportation planners. Outreach and TrainingThe CTPP team provides training
6、 on data and data issues in many formats, from live briefings and presentations to hands-on, full-day courses. The team has also created a number of electronic sources of training, from e-learning to recorded webinars to downloadable presentations. Technical SupportCTPP provides limited direct techn
7、ical support for solving data issues; the pro- gram also maintains a robust listserv where many issues are discussed, dissected, and resolved by the CTPP community. ResearchCTPP staff and board members routinely generate problem statements to solicit research on data issues; additionally, CTPP has f
8、unded its own research efforts. Total research generated or funded by the current CTPP since 2006 is in excess of $1 million. Staff Penelope Weinberger, CTPP Program Manager Matt Hardy, Program Director, Policy and Planning Janet Oakley, Director of Policy and Government Relations Project Team Steve
9、n E. Polzin, Co-Author, Center for Urban Transportation Research, University of South Florida Alan E. Pisarski, Co-Author, Consultant, Falls Church, Virginia Bruce Spear, Data Expert, Cambridge Systematics, Inc. Liang Long, Data Expert, Cambridge Systematics, Inc. Contact Penelope Weinberger, e-mail
10、: pweinbergeraashto.org, phone: 202-624-3556; or CTPPinfoaashto.org 2013 by the American Association of State Highway and Transportation Officials. All rights reserved. Duplication is a violation of applicable law. Pub Code: CA10-4 ISBN: 978-1-56051-581-4 2013 by the American Association of State Hi
11、ghway and Transportation Officials. All rights reserved. Duplication is a violation of applicable law.Commuting in America 2013: The National Report on Commuting Patterns and Trends Brief 10. Commuting Mode Choice This brief is the tenth in a series describing commuting in America. This body of work
12、, sponsored by the American Association of State Highway and Transportation Officials (AASHTO) and carried out in conjunction with a National Cooperative Highway Research Program (NCHRP) project that provided supporting data, builds on three prior Commut- ing in America documents that were issued ov
13、er the past three decades. Unlike the prior reports that were single volumes, this effort consists of a series of briefs, each of which addresses a critical aspect of commuting in America. These briefs, taken together, comprise a comprehensive summary of American commuting. The briefs are disseminat
14、ed through the AASHTO website (www.transportation.org). Accompanying data tables and an Exec- utive Summary complete the body of information known as Commuting in America 2013 (CIA 2013). Information on mode use for commuting is a critical aspect of understanding com- muting and a central issue in t
15、ransportation policy. The inclusion of commuting mode questions in the American Community Survey (ACS) is testimony to the importance of commuting mode choice. The terms “mode usage, ” “mode choice, ” or “modal split” are often used to describe the decisions people make regarding their travel means.
16、 No aspect of commuting is more fraught with public policy interest than is the means of travel or mode chosen by workers to get to their work locations. 1One aspect of this is the desire to un- derstand which modes are employed and in what ways as part of the need to supply public infrastructure an
17、d services, but, more often today, there are also concerns about energy use, emissions, and safety of each mode and other direct and indirect economic, social, and environmental factors that are of public policy concern. Of particular interest to many analysts and policymakers are changes in the ext
18、ent of use of various modes of commuting. Understanding commuting mode trends provides insight into both transportation infrastructure and service needs and the quality-of-life-related consequences of travel. Transportation analysts know that mode use varies as a function of the socio-demographic ch
19、aracteristics of com- muters, the geographic distribution of residence and work places, and the quality and availability of various modal op- tions. This brief explores many of the relationships between these characteristics and commuting mode choice. This 1The mode categories employed here primaril
20、y are those used by the Bureau of the Census in its American Community Survey (ACS) based on modes “usually used” last week. Other approaches are treated later in this brief and are identified when used. The inclusion of mode choice questions in the American Community Survey is testimony to the impo
21、rtance of commuting mode choice. 2013 by the American Association of State Highway and Transportation Officials. All rights reserved. Duplication is a violation of applicable law.4 Commuting in America 2013: The National Report on Commuting Patterns and Trends overview brief addresses national and r
22、egional trends in mode use and is complemented by a series of briefs that address trends within the major individual modes. Understanding trends and conditions is a function of the data collected and how they are analyzed. Although there are probably more resources expended on measuring the modes ch
23、osen for work trips than any other expenditure for transportation statistics, the available data are still relatively limited, particularly given the increasing interest in modes that typically represent niche levels of use. In large part, this is because the seem- ingly straightforward activity kno
24、wn as commuting is really a complex bundle of activities that has become more complex over time. The Commuting in America series over several decades has shed light on the complexity of commuting and its changes over time, yet our understanding of commuting behavior and the pace of change suffer fro
25、m both the absence of a fully-developed theory of commuting behavior and data shortcomings. 2013 by the American Association of State Highway and Transportation Officials. All rights reserved. Duplication is a violation of applicable law.5 Brief 10. Commuting Mode Choice Overall Trends Over the last
26、 50 years, American commuting patterns have followed the seemingly straight- forward lines shown in Figure 10-1. In effect, almost all of the growth in travel to work has been met by auto use, either by those driving alone or in carpools. The recent slowing in growth of private vehicle use seen in F
27、igure 10-1 is due predominantly to the decline in the growth of the total number of commuters in the past decade in contrast to the average growth in workers in previous decades over the baby boom period. There are many other factors at play here; the details of individual modes, the geographic patt
28、erns and trends, the influence of an aging population, the influx of immigrants, and the changing character of the overall economy all have some effect. In addition, the supply of facilities and services, market costs, and changes in societal interests and concerns are interwoven in the patterns and
29、 trends as well. Figure 10-1. Long-T erm Commuting Trend Source: Census, ACS 2010 Looking at the data in more detail increases the understanding of what is happening in the broad trends. When the trend line for Private Vehicles shown in Figure 10-1 is disaggre- gated into its two componentsSingle Oc
30、cupant Vehicle (SOV) (a person driving alone) and Carpool (groups of two or more workers sharing a vehicle)the pattern is more clear, as shown in Figure 10-2. Drive Alone continues to grow in share of total commuting, while the share of Carpool has declined continuously since measurements began. As
31、a result, the numbers of car users has grown over the period, but the number of cars they use has grown 0 20 40 60 80 100 120 140 1960 1970 1980 1990 2000 2010 Millions Private Vehicle Public Transportation Walk/Work at Home The slowing growth of auto commuting is predominantly a result of slowing g
32、rowth in total commuting but also reflects growth in work at home and in public transit commuting. 2013 by the American Association of State Highway and Transportation Officials. All rights reserved. Duplication is a violation of applicable law.6 Commuting in America 2013: The National Report on Com
33、muting Patterns and Trends even faster, with 86.3 percent of all workers in private vehicles. In effect, persons per car or vehicle occupancy for commuting has declined. Figure 10-2. Private Vehicle Mode Share Trend Source: Census, ACS 2010 Brief 12 explores private vehicle commuting in more detail.
34、 Brief 13 explores transit commuting, and Brief 14 explores walk and bicycle commuting in greater detail. Trends in the modes of travel other than private vehi- cle travel are shown in greater detail in Figure 10-3. These other modes are separated from private vehicles so that the detailed patterns
35、are not masked by the magnitude of the differences between them as in Figure 10-1. But, even at this level, some modal patterns are unclear. Three trends stand out here and are worth noting: The multi-decade decline in transit use has reversed, with a modest rebound since 2000. There is a continuing
36、 but slowing decline in walking to work. There is a trend of increases in working at home (W AH) that accelerated in the last decade. 64.4% 73.2% 75.7% 76.6% 19.7% 13.4% 12.2% 9.7% 0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 1980 1990 2000 2010 Mode Share Drive Alone Carpool Drive Alone continues to grow
37、 in share of total commuting, while the share of Carpool has declined continuously since 1980. 2013 by the American Association of State Highway and Transportation Officials. All rights reserved. Duplication is a violation of applicable law.7 Brief 10. Commuting Mode Choice It may be most helpful to
38、 consider commuting shares as having three categories. The dramatically dominant share is Private Vehicle commuting. A second category consists of Transit, Work at Home 2 , and Walkwhich have similar share values, and a third category consists of Bicycle, Motorcycle, Taxi, and Other modes, each of w
39、hich is used by fewer than 1 percent of workers. Figure 10-3. Detailed Mode Use Share Trend (Private Vehicles Excluded) Source: Census, ACS 2010 A clearer way to see what has happened in the last decade is the identification of the net changes in the modes, as shown in Figure 10-4. It can be seen th
40、at only 8.7 million workers were added from 20002010, according to the ACS. SOV gained 7.8 million, while Carpool lost significant users, and Transit increased. W AH gained appreciably in the decade, almost double Transit. While the SOV increase from 2000 to 2010 accounts for 90 percent of the growt
41、h in workers, this share is actually a decline from prior decades where SOV growth was sufficient to capture all new workers and absorb workers who were abandoning other modes. Table 10-1 provides the detailed statistics by mode for the previous four decades. 2Work at Home is not actually a mode of
42、travel; rather, it is the absence of travel. However, it is often shown in analyses for completeness so that all workers are represented. In comparing commuting data, readers should use caution as to whether or not Work at Home is included in the commuting population (denominator) when shares are ca
43、lculated. 6.2% 5.1% 4.6% 4.9% 5.6% 3.9% 2.9% 2.8% 2.3% 3.0% 3.3% 4.3% 0% 1% 2% 3% 4% 5% 6% 7% 1980 1990 2000 2010 Mode Share Public Transportation Walk Work at Home Taxicab Motorcycle Bicycle Other Means 2013 by the American Association of State Highway and Transportation Officials. All rights reser
44、ved. Duplication is a violation of applicable law.8 Commuting in America 2013: The National Report on Commuting Patterns and Trends Figure 10-4. Net Change in Workers 20002010 Source: Census, ACS 2010 Table 10-1. Long T erm Modal Usage Trends 1980 1990 2000 2010 000 % 000 % 000 % 000 % T otal Worker
45、s 96,617 100.00 115,070 100.00 128,279 100.00 136,941 100.00 Drive Alone 62,193 64.37 84,215 73.19 97,102 75.70 104,858 76.57 Carpool 19,065 19.73 15,378 13.36 15,634 12.19 13,266 9.69 Transit 6,008 6.22 5,889 5.12 5,869 4.58 6,769 4.94 Taxicab 167 0.17 179 0.16 200 0.16 151 0.11 Motorcycle 419 0.43
46、 237 0.21 142 0.11 267 0.19 Bicycle 468 0.48 467 0.41 488 0.38 731 0.53 Other 703 0.73 809 0.70 901 0.70 1,178 0.86 Walk (only) 5,413 5.60 4,489 3.90 3,759 2.93 3,797 2.77 Work at Home 2,180 2.26 3,406 2.96 4,184 3.26 5,924 4.33 Source: Census, ACS 2010 What Table 10-1 indicates is that 40.3 million
47、 workers were added from 1980 to 2010, with an additional 42.7 million SOV users, whereas carpoolers declined by 5.8 million. In the same time period, among the modes with the lowest shares, Work at Home gained the most, at 3.7 million; Transit gained 0.8 million, “Other” gained 0.5 million, and Bic
48、ycle gained almost 0.3 million. Walk was the other mode losing commuters, with a 1.6 million loss. Both Taxicab and Motorcycle lost slight amounts, although significant in their share. Note that, overall, because of the sharp declines in Carpool, the total Private Vehicle share rose only from 84.1 p
49、ercent in 1980 to 86.3 percent despite the near 70 percent increase in SOV driving. In terms of scale of change, W AH was the major gainer, increasing Drive Alone Total Workers Carpool Public Transportation Walk Work at Home Taxicab Motorcycle Bicycle Other 8,662 7,756 -2,368 900 - 49 125 243 277 38 1,740 -4,000 -2,000 0 2,000 4,000 6,000 8,000 10,000 Thousands 2013 by the American Association of State Highway and Transportation Officials. All rights reserved. Duplication is a violation of applicable law.9 Brief 10. Commuting Mode Choice 1
