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2 U.S. Transportation Today Transportation—the movement of people and goods—is central to economic activity and to the daily lives of Americans. A well-functioning transportation system allows people to access more places of work, obtain a wider range of goods and services, and connect socially over broader areas. It allows businesses to situate in locations that are best suited to accessing labor, raw materials, and customers. Until the 19th century, local travel was limited by the distance people could walk or ride under horse power. Overland goods transportation was limited to relatively small shipments moved by horse-drawn wagons over poorly built and main- tained roads. Wind- and human-powered ships could carry people or goods greater distances over the waterways, but at slow speeds and often at con- siderable risk. These circumstances placed restrictions on where people could live and work, how businesses could organize, and how societies could specialize and trade. The application of steam power to inland and oceangoing ships and to locomotives operating on steel rails marked a dramatic break with the long history of nonmechanized transportation. By the end of the 19th century, electricity was being used to power streetcars in dozens of cities and the internal combustion engine was being introduced to power small auto- mobiles. These innovations, all made possible by the use of fossil fuels— first coal and then petroleum—led to radical increases in transportation speed and radical decreases in transportation costs. Changes in the locations and interactions of people and businesses followed the introduction of 37

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38 Policy Options for Reducing Energy Use and Greenhouse Gas Emissions from U.S. Transportation faster and cheaper modes of transport. Along with dramatic improvements in communications, advances in transportation were critical in enabling today’s socially and economically integrated world. The progress in transportation has entailed large costs, many stem- ming from the fossil fuels used for energy. Since the phasing out of coal to power railroads and ships, the transport sector has become almost totally dependent on petroleum-based fuels and is now the largest single source of demand for petroleum in the United States and worldwide. Transportation has thus become a major source of emissions of carbon dioxide (CO2) and other greenhouse gases (GHGs) as well as the root cause of other environ- mental disturbances such as oil spills and leaks. In addition, because of its dependence on oil, transportation is the main reason for the country’s interest in ensuring the security of the world’s oil supplies. This chapter presents an overview of the U.S. transportation system today. The scale, scope, and patterns of personal and goods transportation are described, and the energy use and associated emissions characteris- tics of the major transport modes are summarized. Some of the databases examined in this chapter, which was developed during 2009, have under- gone updates that could not be included here.1 While the updates do not appear to convey trends or relationships that are fundamentally different from those presented in the chapter, their analyses over the next several years should prove valuable for energy policy making. Scale, Scope, and Patterns of Personal and Goods Transportation Discussions of transportation generally distinguish between the trans- portation of people and the transportation of goods. The two activi- ties are measured differently and are believed to play different roles in the economy. Yet the boundary between them is not always distinct and tends to change over time. Consider the evolution of transporta- tion’s role in how people shop for goods. Before nearly every household 1 For example, during 2010 the U.S. Department of Transportation began releasing data from the 2009 National Household Travel Survey (NHTS). However, the release occurred too late for inclusion in this report, which thus cites the 2001 NHTS data.

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39 U.S. Transportation Today had access to an automobile, people walked or took public transit to do their shopping, and stores delivered goods that people could not carry home. People unable to access stores placed orders from cata- logs for delivery by mail. Both types of delivery would be counted as “goods” transportation. However, as more and more people began to use their personal vehicles to access stores, they transported most of what they purchased in their vehicles. Even though goods are moved by vehicle, the movements are now categorized as “personal” transporta- tion. Today, as a growing share of goods is being ordered over the Inter- net and delivered in packages to the buyer’s home or place of business, the distinction between personal and goods transportation is chang- ing once again (see Box 2-1). Over the past 10 years, transporting such packages has become a major business for the U.S. Postal Service and private transportation firms such as UPS and FedEx. From the standpoint of sector energy use, the changing boundary between personal and goods transportation may be more than of aca- demic interest. Carriers such as UPS and FedEx have invested heavily in developing electronic systems that enable the tracking of packages as well as in optimizing delivery routes to reduce energy use and other costs. They are also experimenting with delivery vehicles that use fuels other than gasoline or diesel or that are gasoline–electric or diesel–electric hybrids. The net effect of this trend on transportation energy use remains unclear and may not be understood for some time. The shifting bound- ary between personal and goods transportation is also characteristic of transportation’s dynamic nature, which can complicate the forecasting of transportation trends over the course of many decades. personal transportation The transportation of people accounts for about two-thirds of total transportation energy consumption. Thus, knowledge of the current characteristics of this activity and the factors driving it is helpful in gaining insight into where transportation energy use and emissions may be heading. The primary source of information on personal travel trends and patterns in the United States is the National Household Travel Survey (NHTS). The NHTS samples households living in both urban and rural

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40 Policy Options for Reducing Energy Use and Greenhouse Gas Emissions from U.S. Transportation box 2-1 Growth of E-Commerce The U.S. Census Bureau defines “e-commerce” as the value of goods and ser- vices sold over the Internet. Other forms of in-home shopping include cata- log sales, with orders being mailed in and sales made by telephone. In 2008, the latest year for which data were available during this study, e-commerce accounted for 16.5 percent of all “shipments, sales, or revenue,” or $3.7 tril- lion. Approximately 92 percent of this total consisted of business-to-business transactions. The remainder, $288 billion, consisted of business-to-customer transactions. About half of this, $142 billion, consisted of retail sales— shopping from home by using the Internet. According to the Census Bureau, e-commerce increased from 1.1 percent of retail sales ($34 billion) in 2001 to 3.6 percent of retail sales ($142 billion) in 2008. In general, conventional retail stores have not been very successful in developing e-commerce channels in parallel with their in-store shopping. In 2008, e-commerce sales by food and beverage stores accounted for only 0.2 percent of their total sales. The only sector to have achieved any signif- icant success is motor vehicle and parts dealers. With 2.5 percent of their 2008 retail sales accounted for by e-commerce, such dealers contributed 68 percent of all e-commerce sales made by stores. Most business-to- customer e-commerce is conducted by nonstore retailers, most of which are classified by the Census Bureau as “electronic shopping and mail order houses.”a The e-commerce activities of these retailers nearly tripled, increas- ing from $27 billion in 2001 to $111 billion in 2008. a Nonstore retailers other than electronic shopping and mail order houses consist of direct selling establishments (e.g., door-to-door sales), vending machine operators, mobile food services, and heating oil and propane dealers. SOURCE: U.S. Census Bureau, E-Stats, May 27, 2010, p. 2. http://www.census.gov/econ/estats/ 2008/2008reportfinal.pdf. areas. Respondents are asked to detail their trip-making activity, including trip purpose, mode, duration, and distance. An NHTS has been conducted every 5 to 8 years since 1969.2 Although the NHTS was most recently conducted in 2009, its final results were not released in time for this report, which refers to the 2001 NHTS results instead. 2 The name of this travel survey has changed over the years, but all previous versions are referred to in this report as the National Household Travel Survey.

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41 U.S. Transportation Today The 2001 NHTS reported that during that year, individuals aged 5 and older made a total of 1.05 billion person trips3 each day, totaling some 10.4 billion person miles. For the year as a whole, the average household (consisting of 2.6 persons) made about 3,600 person trips and traveled approximately 35,200 person miles. In comparison, the corresponding numbers were 2,600 person trips and 22,800 person miles per household for 1983. Thus, over a period of less than 20 years, households increased their travel by about 50 percent. The growth in household travel was the result of a confluence of demographic, social, and economic factors. For example, between 1983 and 2001 1.9, while the percentage of households without a motor vehicle fell These data reflect fundamental changes that have been taking place in economic and demographic patterns in the United States over the course of decades, all of them influencing transportation. One of the most important was suburbanization. Although it began centuries ago, suburbanization accelerated in the second half of the 20th century. Suburbs started to take on a different function by becoming sources of economic and employment activity rather than merely being bed- room communities. The 1960 U.S. census, for example, reported that most metropolitan-area commuters traveled between suburban homes and center city jobs. By the 1980 census, the dominant flow was from suburb to suburb. By 2000, suburb-to-suburb commutes accounted for 3 Person trips consist of “daily trips” that have a one-way distance of under 50 miles and “long- distance trips” that reach or exceed 50 miles. Because of the way the NHTS data are collected, daily trips and long-distance trips are not mutually exclusive. Daily trips, or combinations of daily trips into home-to-home journeys, can result in travel of more than 50 miles from home. Therefore, these trips are included in estimates for both daily travel and long-distance travel.

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42 Policy Options for Reducing Energy Use and Greenhouse Gas Emissions from U.S. Transportation 41 percent of all daily commute trips, compared with 18 percent for commutes from suburb to center city (Pisarski 2006, 53, Table 3-6). Between 1990 and 2000, commutes from suburb to suburb accounted for 64 percent of the growth in commute trips, while commutes from center city to center city accounted for only 3 percent of the growth (Pisarski 2006, 52, Figure 3-10). Whether such a confluence of economic and demographic factors will emerge again is an important issue in projecting future growth in vehicle miles of travel (VMT) and thus in projecting transportation energy use and emissions. In making VMT projections for the U.S. Department of Transportation, Polzin (2006) acknowledges the important role of the various economic and demographic factors listed above in driving past growth in personal travel, particularly by automobile. He expects many of the same factors to continue to influence VMT, but to a lesser degree, for the following reasons: increase, increase, decline, and In addition, there is evidence of saturation in vehicle ownership and time budgets for travel. Significant growth in VMT cannot come from shifts away from other modes, such as walking, bicycling, carpooling, or transit use, since activity in these modes is already fairly small. However, the influence of other emerging and anticipated economic and demo- graphic trends bears watching. For example, changes in household size and age structure may exert a significant role as most of the baby boom generation reaches retirement age. Smaller households with fewer com- muters may engage in less work-related travel but in more travel for other purposes such as shopping and dining out.

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43 U.S. Transportation Today Changing Purposes of Household Travel The 2001 NHTS asked respondents to identify the reasons for their travel and provided 36 choices.4 Table 2-1 groups these choices into the seven general categories: to and from work, work-related business, shopping, other family and personal business, school and church, social and recre- ational, and other. Although it is a common perception that trips to and from work, or “commuting,” account for the largest share of household travel, they do not. During the 1990s, the share of adults in the workforce stabilized and one-person households grew faster than multiperson households, moderating the rate of growth in commuting trips. In 2001 commut- ing accounted for just 16 percent of all household person trips and for approximately 19 percent of household person miles traveled. In contrast, “household-serving” travel—consisting of trips for shopping, errands, chauffeuring family members, and so forth—accounted for the largest share of travel, representing 44 percent of person trips and one-third of all household person miles. Shopping trips alone accounted for more person trips than commuting. Over the years, the number of shopping trips has increased relative to the number of commuting trips, as shown in Table 2-1. The daily commute is still an important trip category because of its temporal and spatial peaking. However, between 1983 and 2001 trips for purposes other than commuting accounted for the lion’s share of growth in person trips per household (97 percent), average person miles traveled per household (83 percent), average vehicle trips per household (91 percent), and average VMT per household (77 percent). Understanding these changing trends in personal travel is impor- tant in targeting transportation policy making to curb transportation energy use. The trends are intimately connected to more fundamental changes that have been taking place in the size and structure of house- holds, labor markets, information technologies, and patterns of urban- ization. The influence of these broader trends suggests the implausibility of significantly altering travel behavior through targeted transporta- tion policies. For example, policies aimed at changing commuting 4 A more detailed list of these reasons is given by Hu and Reuscher (2004).

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table 2-1 Person Trips per Household and Person Miles Traveled per Household, 1983 and 2001, Based on NHTS Data Person Trips per Household Average Annual Person Miles Traveled per Household Percent Percent Percent Percent Share Share Percent Share Share Percent of 1983 of 2001 Change Change of 1983 of 2001 Change Change Trip Purpose 1983 2001 Trips Trips 1983–2001 1983–2001 1983 2001 PMT/HH PMT/HH 1983–2001 1983–2001 To or from work 537 565 20 16 28 5 4,586 6,706 20 19 2,120 46 (commute) Work-related 62 109 2 3 47 76 1,354 2,987 6 8 1,633 121 business Shopping 474 707 18 20 233 49 2,567 4,887 11 14 2,320 90 All other family 456 863 17 24 407 89 3,311 6,671 15 19 3,360 101 and personal business School and 310 351 12 10 41 13 1,522 2,060 7 6 538 35 church Social and 728 952 28 27 224 31 8,964 10,586 39 30 1,622 18 recreational Other 61 30 2 1 500 1,216 2 3 716 143 −31 −51 All purposes 2,628 3,581 100 100 953 36 22,802 35,244 100 100 12,442 55 Noncommute 2,091 3,016 80 84 925 44 18,216 28,538 80 81 10,322 57 trips only NOTE: HH = household; PMT = person miles of travel. SOURCE: Hu and Reuscher 2004, Table 5, p. 15.

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45 U.S. Transportation Today patterns, such as public investments in transit services, may be desir- able for many reasons such as alleviating traffic congestion, but they may not be as effective in reducing total transportation energy use as they have been previously. Continued Dominance of Automobiles for Personal Travel By the time of the 2001 NHTS, private automobiles dominated as the mode used for all trip types: work-related business trips (91 percent), family or personal business (including shopping) (91 percent), school or church trips (71 percent), social and recreational trips (81 percent), and “other” trips (67 percent). Whether measured by the number of person trips or the number of person miles traveled, the vast majority of house- hold travel is by personal vehicle. In 2001, personal vehicles accounted for 86 percent of daily person trips, followed by walking (8.6 percent), public transport (1.6 percent), and “other” (2.4 percent).5 Automobiles dominate not only local travel but also long-distance travel. In 2001 personal vehicles accounted for 91 percent of all long-distance per- son trips and 65 percent of long-distance person miles.6 Personal vehicles are used most for trips under 500 miles (95 percent of long-distance trips), but they also account for a majority (62 percent) of trips between 500 and 749 miles. Air transport does not become the dominant mode until trips exceed 750 miles. Even for such longer trips, the automobile offers flexibility in departure and arrival times, passenger- and cargo-carrying capacity, and utility for local travel on reaching the final destination. There are many reasons for the dominance of cars and light trucks for personal transportation. The continued suburbanization of jobs as well as homes has profoundly affected the use of private vehicles for travel. In 1960, when the majority of commuters either lived and worked in cities or commuted from suburbs to cities, commuting by foot and public transit was still common. Cities had the densest public transport networks, and public transport systems offered good connections between suburbs and the city center.7 However, as the amount of suburb-to-suburb commuting 5 For daily trips, the “other” category includes bicycles. 6 See Transportation Energy Data Book: Edition 27, 2008, p. 8-25. U.S. Department of Energy. 7 The influence of public transit systems on urban and suburban development is well documented by Warner (1978) and Jones (1985).

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46 Policy Options for Reducing Energy Use and Greenhouse Gas Emissions from U.S. Transportation rose, the use of public transport fell, both in absolute terms and as a percentage of total commute trips. The relationships among household location, workplace location, trip-making activity, and automobile travel have been subjects of research for many years. The studies reveal the thorough integration of the automobile into the daily lives and work patterns of Americans. goods transportation The principal modes used to transport goods within the United States are truck, rail, barge, airplane, and pipeline.8 The transportation of goods accounts for approximately 28 percent of domestic transportation energy use and for about the same percentage of U.S. transport-related CO2 emis- sions. In 2007, the U.S. freight transport system moved nearly $12 trillion worth of goods weighing about 13 billion tons, and it moved these goods 619 miles on average per shipment. Many goods shipments are small, weighing less than 50 pounds, and in the aggregate these many small shipments account for only 0.2 percent of the weight of all goods shipped. Nevertheless, many of these small ship- ments are moved long distances by truck and air and thus account for a significant amount of vehicle travel. On the other end of the spectrum, more than half of all shipments weigh more than 50,000 pounds, and about one-third weigh more than 100,000 pounds. Shipments weighing more than 100,000 pounds account for 57 percent of the total ton-miles hauled. They also account for the longest average shipment distance (595 miles). Shipments moved less than 50 miles account for about 33 percent of the value and 55 percent of the weight of all goods shipped. Although many of these large shipments are moved by rail and water, trucks are also a major mode of travel. Diversity of Use of Trucks for Goods Transportation Table 2-2 shows the tonnage, ton-miles, and value of goods trans- ported in 2007 by each of the major freight-carrying modes, plus mode 8 The energy and CO2 emissions data referenced in this section exclude the transport of goods to and from the United States by air or water. Oil, natural gas, and petroleum products transported by pipeline are also excluded.

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table 2-2 Freight Shipment Characteristics by U.S. Transportation Mode, 2007 Value Percent Share Tons Percent Share Ton-Miles Percent Share Average Miles Shipment Value Mode of Transportation ($ millions) of Value (thousands) of Tons (millions) of Ton-Miles per Shipment ($/ton) All modes 11,684,872 100 12,543,425 100 3,344,658 100 619 932 Truck 8,335,789 71 8,778,713 70 1,342,104 40 206 950 Rail 436,420 4 1,861,307 15 1,344,040 40 728 234 Water 114,905 1 403,639 3 157,314 5 520 285 Air 252,276 2 3,611 0 4,510 0 1,304 69,863 Pipeline 399,646 3 650,859 5 S NA S 614 a 1,866,723 16 573,729 5 416,642 12 975 3,254 Multiple modes Other and unknown 279,113 2 271,567 2 33,764 1 116 1,028 NOTE: S = sample insufficient; NA = not applicable. Values may not add to total because of rounding. a Includes truck and rail; truck and water; rail and water; and express, parcel, and small package delivery services. SOURCE: Bureau of Transportation Statistics and Transportation Commodity Flow Survey, U.S. Bureau of the Census, December 2009.

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68 Policy Options for Reducing Energy Use and Greenhouse Gas Emissions from U.S. Transportation be readily changed, and labor agreements often limit the use of part-time workers. As a result, average energy efficiency per rider suffers. Recent trends in public transit use do not indicate increased energy or emissions efficiency in the public transit sector. According to data from the American Public Transportation Association (APTA), vehicle hours of transit service nationwide increased by 34 percent between 1998 and 2008, but passengers per vehicle hour decreased by 10 percent, from 37.7 to 33.9. There are several reasons for these countervailing trends. The most significant may be the disproportionate growth of transit service in newer metropolitan areas and the suburbs of older cities where densities are lower and automobile use dominates.20 intercity passenger rail energy characteristics In the United States, most intercity passenger rail service is provided by a single company, Amtrak, which was created in 1971 to absorb nearly all of the passenger services of the nation’s railroads. Before Amtrak’s creation, passenger service had been losing large sums of money for decades and was being cut back severely by the railroads then providing it. Amtrak’s takeover was intended to ensure that at least some intercity passenger rail service remained. On a passenger mile basis, intercity rail (Amtrak) is more energy efficient by about 25 to 35 percent than its chief competitors, aviation and personal vehicles, for long-distance markets of 200 to 800 miles. Inter- city rail, however, serves only about 500 stations nationwide and carries 5.5 billion passenger miles per year, which is less than 1 percent of total passenger miles. But in at least one corridor—the Northeast Corridor, running from Boston through New York City to Washington, D.C.— Amtrak handles a significant share of total traffic. In 2007, Amtrak’s share of combined rail and air traffic between New York City and Washington was 21 The Northeast Corridor is by far the largest rail passenger corridor in the country. In 2007 it was responsible for 10 million passengers of Amtrak’s total ridership of 25.8 million. The next-largest corridor, the Pacific 20 http://www.apta.com/resources/statistics/Documents/FactBook/2011_Fact_Book_Appendix_A.pdf. 21 Amtrak Annual Report 2007, p. 11.

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69 U.S. Transportation Today Surfliner, had 2007 ridership of 2.7 million.22 Three other corridors had a ridership of between 1.0 million and 1.5 million.23 Amtrak owns its Northeast Corridor tracks. These tracks carry little if any freight and are designed for passenger service. Outside the Northeast Corridor, Amtrak mostly runs on tracks owned by the freight railroads. These tracks are designed to accommodate freight trains, greatly limiting the speeds at which passenger trains can operate as well as the number of passenger trains that can be accommodated. In recent years interest in developing high-speed passenger rail ser- vice in the United States has been growing. In February 2010 the Obama administration announced the provision of startup funds for a limited number of high-speed passenger rail systems around the country. California voters recently approved funding for a dedicated high-speed passenger rail system linking major cities in the state. Numerous studies have investigated the demand for and cost of high-speed intercity rail service. However, the question of what constitutes “high speed” remains to be determined. It is likely that none of these systems, except perhaps the one in California, will resemble the high-speed passenger trains that operate in Europe and Japan, in part because of the high cost of providing dedicated right-of-way. The dense travel corridors of 200 to 800 miles, which are the target markets for this service, represent a small share of total passenger travel, most of which is local and served by automobile and is thus not a candidate for replacement by high-speed rail. The short- to medium-haul markets, where high-speed rail might be viable, are likewise served mainly by automobile, because many travelers (including families) are price-sensitive and are traveling not from center city to center city but from one sub- urban location to another. They value their private vehicle, even for longer-distance travel, because of its carrying capacity and ability to provide local transportation at the destination. High-speed rail may be most attractive for business travelers currently traveling distances 22 The Pacific Surfliner Corridor provides service between San Luis Obispo, Santa Barbara, Los Angeles, and San Diego. 23 These were the Capital Corridor (1.5 million) serving San Francisco, San Jose–Oakland, Sacramento, New York City.

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70 Policy Options for Reducing Energy Use and Greenhouse Gas Emissions from U.S. Transportation of 150 to 500 miles. This application, which could be important in some corridors and would mainly substitute for air travel, is not likely to have large impacts on total transportation energy use and emissions. system-level energy characteristics In considering the energy characteristics and related GHG emissions of individual modes, a major challenge is in recognizing how efforts to change the level of energy use in one mode can have systemwide implications for total transportation energy use. Because of their difficulty, such system- level analyses are rare. However, the need for such a vantage point has long been recognized. A 1977 Congressional Budget Office (CBO) report, Urban Transpor- tation and Energy: The Potential Savings of Different Modes, suggests how to go about taking such a system-level approach for the transportation system. The CBO report appeared shortly after the first oil supply shock, when policy concern was focused for the first time on reducing trans- portation’s use of petroleum, and Congress requested comparisons of energy performance by various modes to inform energy-saving policies. When CBO conducted its analysis, the most frequently cited measure of energy performance was the direct amount of energy consumed per vehicle mile or ton-mile. CBO revealed how this measure was too narrow for the purpose of analyzing net energy effects from policy choices about transportation investments. CBO developed a framework for evaluating energy performance that considers the various interrelated components and sources of transportation energy use. Figure 2-4 shows an adaptation of the basic CBO framework. The first level in the CBO framework, labeled “operations energy,” includes only the energy required to power the vehicles. The second level, “facility and operations energy,” adds to the first level the energy used to run and maintain stations and terminals, manufacture and maintain vehicles, and construct and maintain the way infrastructure used by vehicles. The third level, “modal energy,” recognizes that the means by which the mode is typically accessed by users can have energy implications. For example, public transit systems do not provide door-to-door service. To utilize them, riders must walk, bicycle, drive, or carpool to and from an access point. The additional energy required for this access, including any

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71 U.S. Transportation Today Energy Components of New Energy Impact Category Transportation Service Energy used for propulsion of vehicles Operations energy Average occupancy or load factor per vehicle Facility and Energy used for transportation facility operations and vehicle maintenance energy Energy used for transportation infrastructure construction Means of accessing new service Modal energy Fraction of total trip devoted to access Added circuity Origins of users of new service figure 2-4 Framework for examining energy performance of transportation services. SOURCE: Adapted from CBO 1977. energy consumed because of travel circuity, must be included in calculat- ing the total energy performance of the provided transit service. Similar calculations could be made for the energy performance of freight rail that involves truck connections to and from freight rail terminals. In analyzing the energy implications of enhancements to a particular transportation service (such as providing more frequent bus service),

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72 Policy Options for Reducing Energy Use and Greenhouse Gas Emissions from U.S. Transportation one must add a fourth level to the structure that subtracts energy that would otherwise have been consumed by the new users of the enhanced system. For example, the goal of the enhancement may be to induce high- way users to switch to less energy-intensive modes, such as mass transit or freight rail. Those switching to the new service may use less energy than they would have in using their previous forms of transportation. However, experience shows that enhancements to a transportation service will generate some new transportation users (those who previously did not travel, such as new commuters) or cause some current users of the same service to increase their use. In neither case will there be offsetting reductions in energy use from other modes. As might be expected, it is difficult to obtain the information needed to make such comprehensive, system-level assessments of the complete energy or emissions impacts of transportation policy choices. Such a comprehensive assessment would need to analyze the energy and emissions impacts from investments extending beyond the transportation sector, such as the potential for transit investments to enable denser housing patterns that are more energy efficient. Various estimates of energy used (and GHGs produced) in the manufacturing, distribution, and disposal of transport vehicles, as well as in infrastructure construction and main- tenance and in accessing the mode, have been made. This information can provide insight into the net energy impacts of investing in an alternative mode of transportation. However, all such data tend to be highly site- specific and difficult to extrapolate widely. In this report, therefore, most of the information on transportation-related energy use and emissions is from the consumption of fuel used to power vehicles. Considerations Affecting the Adoption of Fuel-Saving and GHG-Reducing Technologies In 2005, the amount of fuel used by typical transportation vehicles ranged from 541 gallons per year for the average passenger car to 2.4 million gallons per year for the average commercial aircraft (Table 2-11). Fuel used in large amounts, as in the case of aviation, accounts for large costs, and accordingly carriers have an incentive to manage those costs, even when fuel prices are not rising. Between 2003 and 2008, fuel costs rose from

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73 U.S. Transportation Today table 2-11 Vehicle Miles Traveled and Energy Used per Vehicle per Year, 2005 Average Vehicle Miles Average Fuel Used Vehicle Type per Year per Vehicle per Year per Vehicle (gallons) Passenger car 12,427 541 Taxicab 58,333 3,523 Light truck 11,100 686 Single-unit truck 12,400 1,414 Combination truck 68,800 11,698 Transit bus 30,190 6,462 Rail freight locomotive 69,879 184,374 Commercial aircraft 1,003,000 2,384,924 14 to 31 percent of total operating costs for the 21 major U.S. air carriers, from 11 to 26 percent of total operating costs for the Class I railroads, and from 17 to 31 percent of the total operating costs (less rentals and purchased transportation) for the 11 publicly listed road freight carriers.24 Fuel is one of many inputs used in the production of transportation services. For commercial transportation activities, other important inputs include labor, maintenance expenses, and the costs of vehicle ownership. Different combinations of these inputs produce different levels of operating cost. Operating cost itself must be traded off against the revenue that can be generated by using vehicles with different fuel use characteristics or by using different vehicle operating patterns. Thus, fuel-intensive commercial transportation systems (such as air courier services offering overnight delivery of extremely time-sensitive documents and packages) exist in parallel with transportation systems having relatively low fuel intensities (such as barges moving bulk commodities). Also, opportunities to reduce the use of fuel may not be exploited if doing so would cause total operating expenses to increase or if their implementation would cause the transportation service in which they are used to lose demanded attributes such as speed or reliability. 24 Publicly Traded Carrier Database.

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74 Policy Options for Reducing Energy Use and Greenhouse Gas Emissions from U.S. Transportation Commercial operators clearly have a strong incentive to take actions to reduce their fuel costs, but in doing so they must balance the need to avoid increasing their total operating costs or undermining the value of their services. Although carriers may try to pass the higher fuel costs on to their customers, there will be competitive incentives to seek means of reducing these costs (and gaining market share) by reducing the energy intensity of their services. During periods of high fuel prices, carriers may change the patterns of service they provide to save fuel. They may travel more slowly, configure their routes differently, and change the relative utilization of the vehicles in their fleets on the basis of fuel efficiency. However, they face limits on the adjustments they can make and still provide services that meet their customers’ needs. To illustrate the decision-making calculus, Box 2-3 describes the decision-making calculus of a taxicab operator. In the face of rising fuel prices, owners of household vehicles face a somewhat different set of incentives in determining which vehicles they will purchase and how they will utilize them. They are not in the business an end. The automobile is used to travel to work, shop, conduct other forms of personal business, and socialize. To be sure, the cost of owning and operating private vehicles is significant.25 In 2006, 17.6 percent of the average household’s total spending was for transportation.26 Net outlays on vehicles accounted for 6.5 percent of total spending, while purchases of gasoline and oil accounted for 4.8 percent. Thus, when the average price of a gallon of gasoline jumped by about 40 percent from 2006 to mid-2008, consumers incurred an increase of nearly $600 in the average annual cost of operating a vehicle. Because the average household owns 1.9 vehicles, this increase represented a change of about 2 percent in a household’s annual spending. To minimize this expense, the household could adjust its vehicle use patterns, but most practical adjustments would have limited impact. In many cases, the greatest impact could come from 25 In 2007, the average “consumer unit” consisted of 2.5 persons and had 1.9 vehicles (U.S. Bureau of Labor Statistics, Consumer Expenditure Survey 2007, Table 48). 26 Strictly speaking, the data in the Consumer Expenditure Survey refer to “consumer units.” A consumer unit differs slightly from a “household” as defined by the Census Bureau. The difference is small enough to ignore for purposes of this report.

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75 U.S. Transportation Today box 2-3 Fuel Cost Calculus of a Taxicab Owner Consider the different ways that fuel costs influence the decision making of a taxicab owner–operator and the owner–operator of a personal light-duty vehicle. Both may own and operate the same make and model of vehicle. But the average taxicab is driven many more miles each year than is the typical private automobile—58,333 miles for the former versus 12,427 for the latter (Table 2-11). The average taxicab is less energy efficient than the average passenger car—17 versus 23 miles per gallon. The average taxicab is the average private automobile weighs about 3,000 pounds.a Therefore, it is not surprising that the average private automobile used 541 gallons per year in 2005 while the average taxicab used 3,523 gallons. Higher fuel prices will have a greater impact on taxicab fuel costs than they will on fuel costs for the typical automobile. With no change in driving, the increase in gasoline price from its average of $2.89 per gallon in 2006 to $3.98 per gallon in mid-2008 increased the annual costs incurred by the private vehicle owner by $589 to $2,153. For the taxicab owner–operator, the same increase in fuel prices raised annual fuel costs by $3,825 to $14,014. For the taxicab owner–operator, the increase in fuel prices raised the share of operating costs represented by fuel from 20 to 26 percent. This implies that taxicab drivers should be especially interested in smaller, more fuel-efficient vehicles. A growing (but still small) number of taxicabs are hybrid vehicles. However, the taxicab owner–operator faces constraints that may not necessarily apply to the private driver. Taxicabs require more rear seat room and more room to carry luggage or goods. Therefore, the leeway for improving fuel economy by “downsizing” is likely to be less for taxicabs than for private use automobiles. Durability is also likely to be much more important to the taxicab owner–operator, since downtime for repair equates to lost revenue. a These weights are for the 2009 Ford Crown Victoria and the 2010 Toyota Camry. In calendar year 2008, the Camry was the largest-selling passenger car in the United States, with sales of 436,000 units. In that year, approximately 49,000 Ford Crown Victorias were sold. SOURCE: Automotive News.

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76 Policy Options for Reducing Energy Use and Greenhouse Gas Emissions from U.S. Transportation may be large, and it may not be offset by fuel savings for a number of years. Furthermore, in households with only one vehicle, the vehicle may need to be multipurpose, which may limit the degree to which a smaller, more fuel-efficient vehicle is practical. Unsure how long the fuel price increase will last, the consumer may be reluctant to make this outlay and change in vehicle type. Of course, households adjust their vehicle use patterns in the face of higher fuel prices, and they tend to purchase more fuel-efficient vehicles when energy prices are high than when they are low. The sizes of these responses are generally modest. As discussed in more detail in Chapter 4, the short-run price elasticity of gasoline, reflecting changes that are made without purchasing new vehicles, is about 0.10. This means that a 10 percent increase in the fuel cost of driving will lead to a 1 percent decrease in miles traveled. The long-run price elasticity, which reflects the impact of both changes in vehicle use patterns and more fuel-efficient vehicles, is somewhat higher, on the order of 0.30. Summary Assessment The evolution of transport energy use over the past 40 years reflects the tugs of several conflicting forces. In general, transport vehicles of all types became more energy efficient as measured by the energy required per passenger mile or ton-mile of output. However, the demand for the trans- port services these vehicles provide has grown more rapidly than have increases in energy efficiency. There also has been a long-term shift toward more energy-intensive transport modes, particularly from walking and public transportation to cars and light trucks for passengers and from freight rail to truck for goods movement. Therefore, despite the improve- ments in vehicle energy efficiency, transport energy use has grown, and since nearly all energy used by transportation has been petroleum-based, GHG emissions have grown roughly in parallel. If the United States is to reduce transport energy use and GHG emissions significantly over the next 40 years, the energy efficiency of individual transport modes will have to improve more rapidly than it did over the past 40 years. But the data presented in this chapter also

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77 U.S. Transportation Today 3.5 3 2.5 VMT (trillion) 2 1.5 1 0.5 0 00 02 04 06 08 70 72 74 76 78 80 82 84 86 88 90 92 94 96 98 20 20 20 20 20 19 19 19 19 19 19 19 19 19 19 19 19 19 19 19 figure 2-5 VMT by light- and heavy-duty vehicles on U.S. roads. SOURCE: Federal Highway Administration, Highway Statistics Series. http://www.fhwa.dot.gov/ policyinformation/statistics.cfm. suggest that this outcome by itself is not likely to be sufficient. Progress will almost certainly need to be made in reducing growth in activity by the most energy-intensive modes. The most important factor in reducing transport-related GHGs may be moving the transport sector away from its near-total dependence on petroleum-based fuels. Subsequent chapters in this report describe ways in which such changes might be achieved. The challenge of making these changes, especially in affecting the amount of transportation activity and the modes used, should not be underestimated. Having evolved over many decades and reflecting countless decisions about where and how Americans live and businesses operate, today’s transportation systems cannot be easily or quickly altered. Figure 2-5 shows that since 1970, slight declines in miles traveled by cars and trucks have occurred only during periods of economic recession. The general upward trend in motor vehicle travel has been relentless and largely reflective of population growth and the many economic transactions and social interactions that increased mobility

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78 Policy Options for Reducing Energy Use and Greenhouse Gas Emissions from U.S. Transportation enables. The challenge will be in retaining these economic and social benefits, even as the transportation sector and its energy sources undergo substantial change. References abbreviations AAR Association of American Railroads APTA American Public Transportation Association CBO Congressional Budget Office AAR. 2008. Railroad Intermodal Transportation. Washington, D.C., June. APTA. 2007. A Profile of Public Transportation Passenger Demographics and Travel Characteristics Reported in On-Board Surveys. Washington, D.C. APTA. 2008. Public Transportation Fact Book. Washington, D.C., June. Cambridge Systematics, Inc. 2009. Freight Transportation Bottom Line Report: Freight Demand and Logistics. American Association of State Highway and Transporta- tion Officials, Washington, D.C. CBO. 1977. Urban Transportation and Energy: The Potential Savings of Different Modes. Washington, D.C. Hu, P. S., and T. R. Reuscher. 2004. Summary of Travel Trends: 2001 National House- hold Travel Survey. Prepared for the U.S. Department of Transportation and Federal Highway Administration. Dec. http://nhts.ornl.gov/2001/pub/STT.pdf. Jones, D. W., Jr. 1985. Urban Public Transit: An Economic and Political History. Pren- tice Hall, Englewood Cliffs, N.J. Lee, J. J., S. P. Lukachko, I. A. Waitz, and A. Schäfer. 2001. Historical and Future Trends in Aircraft Performance, Cost, and Emissions. Annual Review of Energy and the Environment, Vol. 26, pp. 167–200. Pisarski, A. E. 2006. NCHRP Report 550/TCRP Report 110: Commuting in America III: The Third National Report on Commuting Patterns and Trends. Transportation Research Board of the National Academies, Washington, D.C. Polzin, S. E. 2006. The Case for Moderate Growth in Vehicle Miles of Travel: A Critical Juncture in U.S. Travel Behavior Trends. Center for Urban Transportation Re- search, University of South Florida, Tampa. http://www.cutr.usf.edu/pdf/The%20 Case%20for%20Moderate%20Growth%20in%20VMT-%202006%20Final.pdf. Warner, S. B. 1978. Streetcar Suburbs: The Process of Growth in Boston, 1870–1900 (2nd ed.). Harvard University Press, Cambridge, Mass.