1、Brief 7. Vehicle and Transit Availability Sep Tember 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
2、the U.S. Department 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 po
3、licy and planning 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
4、tabulations 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
5、technical service 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 provi
6、des training 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
7、direct technical 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
8、, CTPP has funded 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 Projec
9、t Team Steven 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 Weinbe
10、rger, e-mail: 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: CA07-4 ISBN: 978-1-56051-577-7 2013 by the American Association
11、 of State Highway 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 This brief is the seventh in a series of briefs that constitute a body of knowledge describing commuting i
12、n America. This body of work, sponsored by AASHTO and carried out in con- junction with a National Cooperative Highway Research Program (NCHRP) project that provided supporting data, builds on three prior documents covering this topic that were issued over the past three decades. Unlike the prior re
13、ports 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 disseminated through the AASHTO website. Accompanying da
14、ta tables and an Executive Summary complete the body of information known as Com- muting in America 2013 (CIA 2013). A key factor in understanding how commuters select the mode of transportation they use to get to work is their access and ability to use the various modes of travel. In particular, au
15、to and transit availability and cost are important factors in commute trip mode choice. Brief 7, Vehicle and Transit Availability explores this issue in the following pages. Brief 7. Vehicle and Transit Availability 2013 by the American Association of State Highway and Transportation Officials. All
16、rights reserved. Duplication is a violation of applicable law.4 Commuting in America 2013: The National Report on Commuting Patterns and Trends 2013 by the American Association of State Highway and Transportation Officials. All rights reserved. Duplication is a violation of applicable law.5 Brief 7.
17、 Vehicle and Transit Availability Licensure Levels The only national source that can address the availability of licenses to drive a vehicle with the necessary associated demographic detail is the National Household Travel Survey (NHTS). 1State-level sources are available through state transportatio
18、n agencies but gen- erally lack further detail regarding the age and other characteristics of license holders. The data in Figure 7-1 indicate that, among the working-age population in America, having a drivers license is nearly ubiquitous. The highest licensure levels tend to occur between ages 30
19、and 60, with steep declines after approximately age 75. The lower level of female licen- sure in older age cohorts is partially attributable to the lower licensure attainment levels of females in prior generations rather than different levels of license relinquishing. Figure 7-1. Persons Ages 16+ wi
20、th Drivers Licenses Source: 2009 NHTS. When stratified by race and ethnicity, as shown in Figure 7-2, a clearer picture emerges. Lower licensure levels among minorities over the age of approximately 60 bring down the overall licensure levels for older-age cohorts. Hispanics, in particular, show low
21、licensure levels for per- sons over age 55. In addition, gender disparity is far lower among the White Non-Hispanic segments. For the White Non-Hispanic population, there is a 3 percentage point disparity between men and wom- en; that difference rises to 6 percentage points among African-Americans,
22、8 points among Asians, and 20 points among Hispanics. These differences often reflect the cultural tradi- tions of the various demographic segments. 1FHW A does have breakdown by state on age and gender; what is not available is race and ethnicity. See https:/www.fhwa.dot.gov/policyinformation/stati
23、stics/2011/dl22.cfm. 0% 20% 40% 60% 80% 100% 1620 2125 2630 3135 3640 4145 4650 5155 5660 6165 6670 7175 7680 8185 8688 89+ Age Group Male Driver Female Driver More than 89 percent of the population ages 16+ hold drivers licenses. Licensure levels increase through early adulthood. 2013 by the Americ
24、an 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 Commuting Patterns and Trends Figure 7-2. Persons with Drivers Licenses Ages 16+ by Race and Ethnicity Source: 2009 NHTS
25、. Table 7-1. Drivers Licenses by Race/Ethnicity and Gender White Non- Hispanic African American Black, Non- Hispanic Asian Only, Non- Hispanic Hispanic/ Mexican American Indian All Population Ages 16+ Male 94.0% 81.9% 89.6% 87.80% 89.1% 91.8% Female 91.8% 77.4% 83.2% 71.28% 85.5% 86.5% All 92.9% 79.
26、3% 86.5% 79.31% 87.2% 89.1% Workers Ages 16+ Male 97.1% 91.4% 97.6% 92.7% 96.2% 92.6% Female 97.6% 92.0% 91.4% 88.3% 98.8% 86.0% All 97.3% 91.7% 94.9% 90.8% 97.5% 89.9% Source: 2009 NHTS. Worth noting is that sharp increases have occurred in the percentages of women having drivers licenses over the
27、NHTS survey series (19692009). This reflects, in part, the chang- ing working roles of women and the aging and declining size of age cohorts in which wom- en had historically been far less likely to have licenses. Note that while there are still gaps among immigrant populations, females actually exc
28、eed males in license-holding among the White Non-Hispanic, African-American, and American Indian worker populations. 0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100% 1625 2635 Age Group White % Drivers Black % Drivers Asian % Drivers Hispanic % Drivers 3645 4655 5665 6675 76All 2013 by the American Assoc
29、iation of State Highway and Transportation Officials. All rights reserved. Duplication is a violation of applicable law.7 Brief 7. Vehicle and Transit Availability Access to Vehicles At the outset, it is important to establish that both the American Community Survey (ACS) of the U.S. Bureau of the C
30、ensus and the NHTS provide data on vehicles, and both sources are used here. Significantly, neither survey treats the subject based on vehicles owned, but rather on where access to vehicles is possible on a regular basis; consequently, the statistics presented here will vary from other sources of ve
31、hicle ownership statistics. 2 The trend in the growth of available vehicles is shown in Figure 7-3. The increase from 20002010 was approximately the same as in the decades from 19601970 and 19801990. Interestingly, the 20002010 decade is the only one where driving age population grew more than perso
32、nal vehicle numbers. This trend reflects a number of factors, including a modest population growth rate for the adult population, challenging economic times, and some evidence of saturation in the availability of vehicles relative to the adult population. Perhaps some changes in alternatives to trav
33、el, such as communication substituting for travel and renewed interest in and availability of options such as transit, bike, and walk, helped dampen interest in expanding auto ownership. Figure 7-3. Additional Vehicles and Driving Age Population per Decade Source: Decennial Census, ACS 2010. Figure
34、7-4 presents a clearer picture of the 50-year trend in changes to the household vehicle fleet. The number of households with one vehicle remained roughly constant for 30 years, but after 1990 it began to increase, perhaps attributable to the influx of immigrant populations and growth in single-adult
35、 households. Note that, for the most part, the great 2The ACS asks about vehicles that are kept at home for use by members of the household. The NHTS refers to vehicles owned, leased, or available for regular use by members of the household. 23.7 47.7 22.1 30.6 22.2 15.0 30.5 19.9 25.6 26.6 0 10 20
36、30 40 50 60 19601970 19701980 Millions Vehicles Population 16 and older 19801990 19902000 20002010 2013 by the American Association of State Highway and Transportation Officials. All rights reserved. Duplication is a violation of applicable law.8 Commuting in America 2013: The National Report on Com
37、muting Patterns and Trends changes were in the two-and three-vehicle households. Households with two vehicles in- creased from about 10 million to more than 40 million in the period, and households with three or more vehicles increased an incredible amount, from 1.3 million to more than 22 million,
38、almost 20 times the 1969 figure. Figure 7-4. Household Vehicle Ownership, 50-Y ear Trend Source: Census, ACS 2010. Perhaps the most significant trend is the slight decline in the absolute number of households with zero vehicles to about 10 million in spite of growth in the total number of households
39、. The share of households with zero vehicles has declined substantially since 1960. Figure 7-5 makes that clear, showing that the zero-vehicle household was more than 20 percent of all households in 1960 and is now down below 10 percent despite the surge in immigrants. 1960 11,400 30,190 10,100 1,30
40、0 1970 11,100 30,300 18,600 3,500 1980 10,400 28,600 27,400 14,100 1990 10,600 31,000 34,400 16,000 2000 10,861 36,124 40,462 18,033 2010 10,397 38,742 43,057 22,371 0 Vehicles 1 Vehicle 2 Vehicles 3+ Vehicles 0 5,000 10,000 15,000 20,000 25,000 30,000 35,000 40,000 45,000 50,000 Households (Thousan
41、ds) 2013 by the American Association of State Highway and Transportation Officials. All rights reserved. Duplication is a violation of applicable law.9 Brief 7. Vehicle and Transit Availability Figure 7-5. Trend in Share of Households by Vehicles in Household Source: Census, ACS 2010. Another facet
42、of the picture is the relatively stable structure of household ownership of vehicles since 1980, as depicted in Figure 7-5, with a small increase in three- vehicle households since 2000. It would appear that there is a relatively stable distribution of households by vehicle ownership level related t
43、o workers per household, stage in the life cycle, and incomes. This pattern may also reflect the relative stabilizing of household size trends after 1980, after sharp declines in earlier decades. Annual zero-vehicle household data available through the ACS show some interesting trends since 2007 in
44、re- sponse to economic conditions. Following decades of de- cline, the number of zero-vehicle households has started to increase from the historic low of 8.7 percent of households in 2007. As of 2011, the share of zero-vehicle households in- creased to 9.3 percent, with 34.1 percent being single-veh
45、i- cle households, 37.5 percent being two-vehicle households, and 19.1 percent being three-or-more-vehicle households. Vehicle ownership (which indicates the prospects of access to a vehicle for commuting) is related to the density of development. Figure 7-6 depicts examples of the intensiveness of
46、development for four ranges of population density used in analysis in this and other briefs in the series. 0% 10% 20% 30% 40% 50% 60% 1960 1970 1980 1990 2000 2010 0 Vehicles 1 Vehicle 2 Vehicles 3+ Vehicles The multi-decade trend of declining zero-vehicle households appears to have played itself ou
47、t. The most current data suggest that the count of zero-vehicle households is now increasing. An aging population, challenging economic times, and increased availability of other travel options may be contributing to the reversal of this trend. 2013 by the American Association of State Highway and T
48、ransportation Officials. All rights reserved. Duplication is a violation of applicable law.10 Commuting in America 2013: The National Report on Commuting Patterns and Trends Zero to 2,000 persons per square mile King County, Washington 2,000 to 4,000 persons per square mileOrange County, Florida 4,0
49、00 to 10,000 persons per square mileFort Worth, T exas 10,000+ persons per square mile New Y ork, New Y ork Figure 7-6. Examples of Population Density Categories Used in Analyzing Commuting Washington: 2013 Google Sanborn, DigitalGlobe, U.S. Geological Survey, USDA Farm Service Agency; Flori- da: 2013 Google DigitalGlobe, Landsat, The Florida Department of Environmental Protection, U.S. Geolog- ical Survey; Texas: 2013 Google DigitalGlobe, Texas Orthoimagery Program, U.S. Geological Survey, USDA F
