The Nation's transportation system exists for the safe and efficient movement of people and goods. Despite recent decreases in overall transportation activity due to the economic recession, the system has grown over the decades in answer to the longterm increasing demand for goods and in response to longterm increases in the number of people who travel as well as in the amount of travel by each person. In 2012 miles of travel by personal vehicle and commercial aviation remained below 2007 levels, while miles of travel by transit and intercity passenger rail continued to grow. At this time, it is too early to tell whether this is a long-term trend or a temporary shift. The numbers from recent years lead to important questions: How much has local and long-distance travel changed in recent years? Are recent changes in travel a temporary departure from long-term trends caused by economic recession, or do changes in travel indicate fundamental shifts in the demographics, geography, and travel preferences of the U.S. population?

Recent Trends in Local Travel

As illustrated in table 3-1, personal travel is dominated by frequent, repetitive patterns such as the daily commute to work and weekly shopping trips. Daily travel includes trips to work, school or shopping, visiting friends or relatives, and attending religious services. Box 3-A discusses the primary data sources on local and long-distance travel. Figure 3-1a shows the shares of person trips by trip purpose and figure 3-1b shows the person-miles of travel for these purposes in 2009. Work and workrelated trips are typically longer than other types of local travel, making up 25.3 percent of total mileage traveled but only 18.7 percent of total trips. The shorter trips were for shopping, personal business, and social/recreation—each with greater shares of the number of trips but a lower share of person-miles of travel than the work commute. For the last 15 years, about one-fifth of trips involve trip-chaining in which people sandwich in daily errands and activities, such as dropping off and picking up children at school/day care or stopping at a fitness center, while on the way to and from work. Such trip-chains are positive in that they save time, distance traveled, and fuel. But chaining also is negative in that trips may be made during peak travel periods rather than during less crowded times, thus adding to congestion. Trip-chaining is not a growing phenomenon, remaining at about 18 percent of total trips over the last 15 years [USDOT FHWA NHTS 2011]. It also reinforces unaccompanied use of the automobile, making it less convenient for drivers to carpool or to use other modes such as transit.

Figure 3-2 traces the number of trips per person per day made for major purposes as shown in the national travel surveys. The number of work and school/church trips has been stable over the period of 1977–2009; however, the shares of work trips have declined relative to other trips as travel for other trip purposes increased.

The number of trips varies throughout the week (figure 3-3). Friday accounts for the most trips, because of more social/recreational and family/personal/errand trips, and Sunday for the least. Reduced numbers of work trips and errands on Saturday and Sunday are partially offset by shopping and social/recreational trips.

As shown in figure 3-4, 83.4 percent of person trips for all purposes are taken in personal vehicles. Walking is used for a significant number of errands and social/recreational trips. Family/personal errands and social/recreational activities accounted for more than two-thirds of trips. They were followed by trips to and from work, which accounted for 15.6 percent.

Supporting the high percentage of travel by personal vehicle, 9 out of 10 households have access to automobiles and other vehicles. The share of households without a vehicle declined from over 20 percent in 1960 to 8.7 percent in 2007 and then began to slowly increase as the economy weakened. The most recent data indicate that 9.2 percent of households in 2012, roughly 10.7 million, do not have access to a vehicle [USDOC CENSUS ACS 2012]. The number of households without vehicles has stayed about the same at 10–11 million despite a growing number of households over the past 40 years [AASHTO 2013].

Most households without access to vehicles do not have members in the labor force. Only 4 percent of households with workers have no vehicles. These households mostly rely on transit or, to a lesser extent, carpooling. About 12 percent of households have more workers than vehicles. The other 88.4 percent are roughly evenly split (about 44 percent each) between households with more vehicles than workers and households where the number of vehicles is the same as the number of workers [AASHTO 2013].

Personal vehicles provided from 84 to 88 percent of journeys to work since 1980 (table 3-2). Carpools and walking dropped as a share of commuting every decade since 1980, while transit increased slightly between 2000 and 2010 after dropping from 1980 to 2000. Although use of private vehicles and walking dropped in share, both increased in absolute numbers from 2000 to 2010 as shown in figure 3-5. Driving alone continued to rise in share while carpooling declined.

The geography of commuting involves two opposing trends. On one hand, workers and their places of work have grown farther apart over recent decades. Workers leaving their home county to work in another county more than quadrupled from 9 million to 38 million and almost doubled in share of all workers between 1960 and 2010. On the other hand, an increasing number of workers are working at home. Part of the longer term growth in working at home had been masked in earlier decades by the number of people who worked on the farm where they also lived [AASHTO 2013].

In 2010, 13.4 million people worked from home at least one day per week, an increase of about 4.2 million people (35.4 percent) from 1997. Home-based workers include those who work exclusively at home as well as those who work at both home and at a job site. Advanced communication and information technologies have increased labor force mobility. Monday and Friday are the most likely days to telework, and Thursday is the least likely day to work from home [USDOC CENSUS 2013b].

National trends do not tell the full picture of travel in individual metropolitan areas. For example, transit use for commuting serves a higher share of work trips in larger metropolitan areas: 11.0 percent in areas with a population over 5 million, 4.0 percent in areas between 2.5 and 5 million, and 2.2 percent in areas between 1 and 2.5 million (figure 3-6). At the highest extreme, 58.7 percent of workers living in the borough of Manhattan in New York City commute by transit and another 20 percent walk [USDOC CENSUS ACS 2012]. In many places, the daily rhythms of local travel are affected by long-distance travel.

Recent Trends in Long-Distance Travel

Highway traffic between distant places contributes to local congestion on intercity highways. Traffic to and from airports also contributes to local congestion. Person movement in recreational areas is dominated by seasonal variation (e.g., holidays, such as Memorial Day) as out-of-town visitors increase traffic counts along interstates that connect major cities and on local roads that lead to resort areas [DELDOT 2014].

When defined as trips to a place over 50 miles away, long-distance travel is primarily served by personal vehicles or air carriers. In 2001 personal vehicles accounted for 89.3 percent of long-distance trips and 55.9 percent of long-distance person-miles, while 7.1 percent of trips and about 40.5 percent of the longdistance person-miles were by air [USDOT FHWA NHTS 2011]. Box 3-B discusses the difficulties distinguishing local highway travel from long-distance highway travel.

Long-distance travel included approximately 67 million international visitors to the United States, as shown in figure 3-7a, in 2012, an increase from the less than 63 million in 2011 [USDOC OTTI 2013]. Figure 3-7b shows the fluctuation in international visits since 2004, reflecting the impacts of the global recession in 2009 [USDOC BEA 2013].

U.S. and foreign airlines carried nearly 824 million passengers on domestic and international flights to and from the United States in 2013. Passenger enplanements were up by about 1.4 percent from 2012, but remained 11.5 million below their 2007 peak. In 2013 domestic enplanements accounted for 78.4 percent of passengers, while international enplanements on U.S. and foreign airlines accounted for 21.6 percent [USDOT BTS OAI 2014]. U.S. airlines carried 54.0 percent of the passengers between the United States and international points. As shown in table 3-3, planes have become more crowded since 2005 as measured by load factors.

The 9.7 million domestic and international flights in 2013 were down 13.3 percent from their 2007 peak just prior to the beginning of the recession in December 2007. Domestic flights in 2013 accounted for 85.8 percent of total U.S. flights, while international flights of U.S. and foreign carriers accounted for 14.2 percent [USDOT BTS OAI 2014].

Long-distance travel on railroads in the United States involves two carriers: Amtrak (also known as the National Rail Passenger Corp.) and the Alaska Railroad. Amtrak ridership has been growing since the late 1990s. After years of tallying about 20 million annual person trips, Amtrak ridership increased to 25 million in the early years of the 21st century, and then rose to a record 31.6 million riders in fiscal year 2013 [AMTRAK 2013]. Annual ridership peaked on the Alaska Railroad in 2007 at more than onehalf million trips, but was down to 489,645 trips in 2013. Customers traveling aboard railcars owned by cruise lines and pulled by the Alaska Railroad accounted for about half of the 2013 Alaska Railroad passengers [ARRC 2014].

Long-distance travel by motorcoach is summarized in table 3-4. The motorcoach industry provided 637 million person trips in the United States and Canada, covering almost 76 billion miles for an average trip length of about 115 miles. In 2012 the 20 large carriers, with more than 100 buses each, accounted for less than 1 percent of operators, but provided 34.7 percent of person trips. Small carriers, with less than 10 buses each, accounted for 82.4 percent of operators, but provided only 24.2 percent of trips. The remaining carriers, with between 10 and 99 buses, provided 41.1 percent of person trips. About half of all bus passengers are either students or senior citizens [ABA 2014].

Forces of Change in Travel

After decades of growth, person-miles of travel (PMT) by the dominant mode of personal vehicles has changed very little since 2008, but personal vehicles continue to account for 86.4 percent of PMT. As described earlier, air travel showed a pattern of growth and decline during the recession. Modest increases in travel by other modes (e.g., transit and intercity passenger rail) do not offset the decline in highway PMT on total travel [USDOT BTS NTS 2014].

Economics and Recession

It remains to be seen if the forces contributing to declining PMT are temporary or long lasting. The recession was clearly a major factor in recent trends. Vehicle-miles traveled (VMT) and the number of domestic commercial aviation enplanements both peaked in 2007. U.S. Gross Domestic Product (GDP) grew at approximately 4 percent per year in the 1990s and about 3 percent per year in the early 2000s, but declined 0.3 percent in 2008 and 2.8 percent in 2009, before again growing each year from 2010 through 2012. VMT of highway vehicles dropped 1.8 percent in 2008, 0.7 percent in 2009, and 0.7 percent in 2011, but had modest growth in 2010 and 2012. Figure 3-8 shows the interrelationship between GDP and VMT. Enplanements on domestic airline flights and ridership on the tourism-sensitive Alaska Railroad also peaked with the economy in 2007 but have yet to return to prerecession levels. Only urban transit and intercity rail passenger volumes grew throughout the recession. The number of passengers on international flights to and from the United States returned to prerecession levels beginning in 2011.

As shown in figure 3-9, person-miles of travel increase with household income. It remains to be seen when the economy and income growth will return to prerecession levels and stimulate a return to prerecession growth in travel, or whether other factors will break the traditional relationships between economic growth and travel.

Demographic and Geographic Shifts

Demographic factors are the traditional driving force behind travel demand in the long-term. Since 1950 the U.S. population has more than doubled—increasing from about 151 million to nearly 314 million in 2012 [USDOC CENSUS 2014]. The U.S. population is still growing, albeit at lower rates than in prior decades, and growth is not even across the country. More than 75 percent of the growth in the Nation between 1950 and 2010 was in the South and West. Although two-thirds of the Nation's counties and 85 percent of metropolitan counties gained population from 2000 to 2010, 175 metropolitan counties and 920 nonmetropolitan counties lost a total of 2 million residents [AASHTO 2013].

Demographic factors and the economy combine to affect travel demand through the growth of the labor force and the subsequent increase in journeys to work, and through growth in the income generated by the labor force, which becomes available for spending on discretionary travel. Growth in the number of workers exceeded the increase in population during the 1970 to 1990 period. In the 1950s the United States added about 7 million workers. In the 1970s the Nation had added more than 18 million more workers and exceeded that total the following decade. In the first decade of this century, only 8.6 million workers were added to the labor force [AASHTO 2013].

Figure 3-10 illustrates the effect of age on travel. Age is closely associated with the progression of the household life cycle (e.g., single person, married couple, households with small children and/or school age children, empty nesters, and retired individuals). Both the youngest (under 16 years of age) and the oldest (over 65 years of age) travel the least compared to other age groups. The other three age groups shown in the figure account for the majority of person-miles traveled (PMT), particularly those between 26 and 65 years of age. This is a harbinger of future trends as older members of the labor force move toward the 65-year-age threshold, when many people move into retirement. Travel across all age groups (except those 16 years old and under) showed declines from 2001 to 2009. The youngest and oldest age cohorts seemed least affected by the December 2007 to June 2009 recession and its aftermath, while the working age groups were most affected, particularly the youngest segment [NBER 2013]. Whether this is cyclical or a fundamental change in travel behavior is not clear.

The baby boom generation, born between 1945 and 1965, has been the driving force for travel activity at the local and intercity level since World War II. As children, baby boomers affected school and child care-related travel, and then as adults they markedly increased the labor force—not only due to their sheer numbers but because women joined the labor force in large numbers. The resulting increase in the average number of commuters per household affected the journey to work as well as other travel patterns, such as dropping children at child care and school. Today, as the trailing edge of the baby boom generation approaches retirement age, boomers are still affecting travel patterns. They are the first generation to have grown up in the automobile age, with both women and men close to reaching the saturation point in terms of driver licenses and vehicle availability. Retired baby boomers thus could be expected to be more mobile in their retirement years than previous generations, as indicated by an increase in PMT among those aged 65 and older [AASHTO 2013].

The millennial generation born after 1980 is often described as having very different attitudes toward location and transportation than their baby boomer parents. Millennials are described as less dependent on the automobile and more likely to live in central cities [SAKARIA STEHFEST 2013]. National data do not corroborate this description: among 16- to-24 year old members of the U.S. labor force who migrated between suburbs and principle cities, 250,000 left the suburbs for cities and 450,000 left the cities for suburbs, for a net loss of approximately 200,000 from 2011 to 2012 [AASHTO 2013]. Teenagers are delaying the time when they acquire a driver's license and purchase their first new car, but the delay may have far more to do with the economy and availability of jobs for youth than with shifting preferences of the younger cohort [AAA 2012]. Transportation as a share of spending is higher for people under the age of 35 than for any other age group [USDOL BLS CEX 2012].

After decades of predictable growth, recent indicators of U.S. travel have become less clear. Many factors, such as the travel predilections of the aging baby boom generation, uncertainties about future levels of immigration, and the duration of continuing effects of the recent recession on travel, will enter into the equation. In order to understand possible changes in travel dynamics, good data about local, long-distance, and international travel will need to be collected on a regular basis. The central question for data development will be to distinguish what changes are cyclical phenomena, and therefore transient, from those that are structural and a fundamental part of a new era of travel behavior.

Challenges for Travel

An important component of accessibility is having access to transportation options, in particular for those groups in society who have the most difficulty traveling. Chapter 1 mentions the degree of connectivity¹ between public transportation modes. Access to transportation for people without a personal vehicle and transportation for the elderly, people with disabilities, and rural residents are all challenges for the transportation system.

Access to Transportation for People Without a Vehicle

Many people without access to a personal vehicle, especially the poor, have difficulty reaching stores, services, and workplaces outside of their immediate neighborhoods. The most recent data indicate that the 1 Connectivity gives shippers and travelers additional transportation alternatives that unconnected, parallel systems do not offer. percentage of households with no vehicle rose slightly to 9.3 percent in 2011 and then declined to 9.2 percent in 2012, roughly 10.7 million households, about the same number of households without a vehicle as in 1980 [AASHTO 2013]. In the most densely populated parts of cities (10,000 plus people per square mile), 28.4 percent of households had no vehicle in 2009 [USDOT FHWA NHTS 2011].

People living below the poverty level are less likely to own, or have access to, a personal vehicle to get to work than the population as a whole. The percentage of people in poverty increased from 12.2 to 15.9 percent between 2000 and 2012 nationally as the number of poverty stricken increased from 33.3 million to 48.8 million [USDOC CENSUS ACS 2013]. BTS analysis of the 2009 NHTS found that households with annual incomes less than $25,000 were eight times more likely on average to be zero-vehicle households than households with annual incomes above that level [USDOT FHWA NHTS 2011]. Of workers below the poverty level, 63.6 percent drive to work compared to 76.4 percent of workers overall in 2012. Compared to commuters as a whole, people below the poverty level are more likely to take public transportation, walk, or use other transportation modes (compare figures 3-11a to 3-11b).

Transportation Access for Elderly and Disabled Passengers

Another important component of accessibility is having access to transportation options, in particular for those groups in society who have the most difficulty in traveling, that is, the elderly and those with physical or cognitive impairments. The American Association of Retired Persons Public Policy Institute estimated that the percent of all trips in the United States taken by persons age 65 and older increased from 11 percent in 2001 to 12 percent in 2009, accounting for 45.2 billion trips [AARP 2011]. The total number of miles traveled by people age 65 and older increased by 7 percent, accounting for 10 percent of all miles traveled in the United States in 2009. Transit use by people age 65 and older as a share of all the trips they take increased by 40 percent between 2001 and 2009, which represented more than 1 billion trips on public transportation in 2009 (a 55 percent increase from what was reported in 2001).

Over the last two decades, the Nation's transit fleet has made notable progress in making transit service accessible to those with disabilities. Through the installation of lifts and ramps or improvements in station infrastructure, people using wheelchairs or who have other travel disabilities now find it easier to access transit than in the recent past [USDOT FTA 2013]. In 2011 the percentage of accessible buses reached 99 percent, compared to 60 percent in 1995. Also during this period, accessible portions of the commuter rail fleet doubled to 85 percent, and accessibility on the light rail and heavy rail fleets reached 88 and 99 percent, respectively. The trolleybus fleet grew from 47 to 100 percent accessible. Demand-response transit fleets have also become more accessible, increasing from 84 to 89 percent.

References

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¹ Connectivity gives shippers and travelers additional transportation alternatives that unconnected, parallel systems do not offer.