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13 U.S. freight transportation is a multimodal system that offers a range of competitive and complementary services. Five modes, including trucks, rail, water, air, and pipelines, provide a variety of options, with intermodal services often tying the options together. The various modes and intermodal services offer advantages and disadvantages in terms of price, speed, reliability, accessibility, visibility, security, and safety. Differences in service characteristics, costs, and prices result in shippers choosing particular modes while transportation providers target particular markets and commodities. âAs a result, truck and air modes are typically used for higher-value, lower-weight, and more time-sensitive freight, while rail and water freight transportation usu- ally serve lower-value, heavier weight, and less time-sensitive shipmentsâ (Brogan et al. 2013). Table 1 illustrates the potential advantages of different modes with respect to the weight of the commodities and distance traveled. A U.S. DOT and FRA report (2010) ranked the various modes of transport in each of the cells by their comparative efficiency. Table 1 shows that rail or waterways are mainly used for bulk or heavy cargo that needs to be transported for more than 500 miles. For lightweight cargo traveling shorter distances (less than 500 miles), the truck mode is used, and, once the distance is more than 500 miles, a truck-rail intermodal option is used. In general, rail or waterways are selected when the cargo is either heavy or needs to be transported longer distances. Truck is mainly used for lightweight cargo or for shorter distances. The tonnage and number of freight shipments within the United States are increasing steadily as demand for consumer goods and other products grows and as manufacturers and retailers move from inventory-based to just-in-time supply chain and distribution systems (Grenzeback et al. 2013). Table 2 summarizes the trends in freight transportation demand, which government and industry have typically measured in tons, ton-miles, and value (dollars) of goods moved.1 As Table 2 shows, the value of each of these measures has increased over each 5-year period, dating back to 1997. Figure 1 disaggregates freight movement in 2010 by mode and by ton, ton-mile, and value data. In 2010, trucks moved about 72 percent of all freight tonnage, accounting for 42 percent of all ton-miles and 70 percent of freight commodity value. Rail accounted for only 11 percent of the tons moved, but 28 percent of ton-miles and 3.5% of total value. This reflects railâs cost- effectiveness in hauling heavier, generally lower-value commodities, such as coal and grain, over long distances. Excluding international maritime shipments, waterborne transportation accounted for a smaller percentage of tons and ton-miles. Air freight transportation constituted an even smaller share, except in terms of value (Brogan et al. 2013). C H A P T E R 2 Historical Patterns in Freight Mode Share 1 A ton of goods moved 1 mile is counted as 1 ton-mile. There is double counting in the reporting of aggregate national freight transportation statistics because sources compile these data by mode, not specific shipment. Data sources count a ton of goods transported 2 miles by truck as 1 ton of freight and 2 ton-miles of freight movement. However, a ton of goods transported 1 mile by truck, then transferred to rail and transported 1 more mile by rail is counted as 2 tons of freight (1 by truck, 1 by rail) and 2 ton-miles of freight movement.
14 Impacts of Policy-Induced Freight Modal Shifts 0â250 250â500 500â1000 1000â2000 >2000 Retail Goods/Light Truck Truck Truck Rail Intermodal Truck Rail Intermodal Truck Rail Intermodal Consumer Durables and Other Manufactured Goods/Moderate Truck Rail Truck Rail Rail Intermodal Truck Rail Rail Intermodal Truck Rail Rail Intermodal Truck Rail Rail Intermodal Bulk Goods/Heavy Truck Rail Water Rail Water Truck Rail Water Rail Water Rail Water W ei gh t Intercity Distance in Miles Source: (U.S. DOT and FRA 2010) Table 1. Potential modal comparative advantage by market. Year Tons (Billion) Ton-Mile (Trillions) Value (Trillion, 2007 $) Value (Trillion, Current $) 1997 16.4 5.4 12.5 0 2002 17.2 5.5 14.2 0 2007 18.9 5.7 16.7 0 2012 19.7 6.2 17.4 17.8 Source: (FHWA 2014b) Table 2. Trends in freight transportation (1997â2012). Source: (Brogan et al. 2013, FHWA 2014a) Figure 1. Share of freight transportation by mode and tons, ton-miles, and value in 2010.
Historical Patterns in Freight Mode Share 15 The purpose of this chapter is to provide an overview of current mode shares and the factors that determine those shares. The first section examines mode shares and shifts from a historical perspective. The second section delves into the current distribution of freight traffic by mode, examining the roles each mode plays in the freight system, and how those have evolved in recent years. The third and final section examines the macro factors that have recently, or are currently, affecting mode shares. These factors include regulation, containerization, and the just-in-time phenomenon. Historical Mode Shares The technology, capacity, and performance of freight transportation systems have changed radically over the past 200 years. Table 3 summarizes the major eras in U.S. freight transporta- tion as the nation moved from the use of water transportation to rail to trucks. In the 1980s, deregulation shaped freight transportation; more recently, computers and information tech- nology have become dominant forces. Technology has allowed shippers and carriers to closely monitor and coordinate production, supply chain, and transportation operations. These trends have reduced the barriers between freight transportation modes, and refocused attention on overall trip performance. Time Period Event Effects Businesses clustered close to sea and river ports to minimize the cost of freight transportation At the time of the American Revolution, it cost as much to move a ton of goods 30 miles inland as to move it across the Atlantic 2 out of 3 settlers lived within 50 miles of the Atlantic coast Freed business and industry from the need to locate near sea, river, and canal port Opened much of the interior of the country and freight transportation costs dropped dnatsewdiMehtfotnempolevedwollofottliuberewsetuorliartsew-tsaE solidify political and military control of the West after the Civil War liarraenetacolotdeenehtmorfyrtsudnidnassenisubdeerF seimonocelanoigerdnaseiticdetcennocsyawhgihfodirgA gnikatsretnecyticmorfdrawtuodetargimseitinummocdnasessenisuB advantage of newly accessible inexpensive land htuos-htrondnaliarmorfciffarttsew-tsaefoerahsegraladerutpacskcurT traffic from coastal steamers and river barges Trucking became the dominant mode of freight transportation, and much of the railroad industry shrank into bankruptcy dna,reirracrotom,daorliar,enilriaehtfognirutcurtserevissamadereggirT marine shipping industries secirpdehsals,secivresdnasetuordengiseder,detadilosnocsmriF sdoogremusnocfostropmiybnevird,edartlanoitanretniniesaercnidipaR and North American trade agreements yrtsudniliarezilativerdeplehnoitazireniatnocfonoitcudortnI ylesolcotytilibaehtsreirracriehtdna,sreliater,srerutcafunamneviG monitor and coordinate production, supply chain, and transportation operations worldwide and locally ,sedomnoitatropsnartthgierfneewtebsreirrabehtdecuderyltaerG refocusing attention on overall trip performance tsebsevrestitahtstekramdnaseitidommocehttegratotedomhcaedecroF and most economically The 1980s Deregulation Today Computers, electronic sensors, digital radio, and satellite communications Colonial economies of the 18th century Water transport Mid-19th century Introduction of rail technology Early 20th century Development of truck and highway technologies Source: (Adapted from AASHTO 2003) Table 3. Historical mode share and shift timeline.
16 Impacts of Policy-Induced Freight Modal Shifts Current Mode Shares This section examines the current distribution of freight traffic by mode, examining the roles that each mode plays in the freight system, and how those roles have evolved in recent years. The first subsection discusses data sources, the analysis and uses of the data sources, and their limitations. The following subsections analyze mode shares over the last 20 years and mode share projections in terms of tons, ton-miles, value, distance traveled, and commodity carried. Data Sources Version 3 of the FAF (FAF3) (FHWA 2014a) is a freight-transportation data program designed to provide a comprehensive picture of freight movement in the United States. Analysts often think of it as a model because of the traffic assignment procedure that FAF uses. The database that makes such a traffic assignment possible is the result of an enormous data compilation that represents the only publicly available comprehensive data for the entire U.S. freight transporta- tion system. FAF is further described below. The CFS that the Census Bureau conducts as part of the Economic Census is the largest source of input data in the FAF and provides the majority of domestic freight movement data. How- ever, the Census conducts this survey only every 5 years, so FAF develops estimates for the most recent years, as well as forecasts, based on trends from specific sources, international trade, and economic data. FAF also uses the origin-destination matrix to conduct network assignment and regional flows, which allows the model to display truck trips, tonnage, and congestion on the National Highway System. FAF3 provides estimates for tonnage, value, and domestic ton-miles by region of origin and destination, commodity type, and mode for 2007, the most recent CFS year, as well as forecasts through 2040. Also included are state-to-state flows for these years, plus 1997 and 2002, sum- mary statistics, and flows by truck assigned to the highway network for 2007 and 2040. FAF has eight domestic modes, including truck, rail, water, air, multiple modes and mail, pipe- line, and other/unknown (for which the mode cannot be determined). The eighth mode is a no-domestic mode category, i.e., there is no movement inside the United States. For example, if there is a shipment of crude petroleum that goes directly to the refinery from the port of entry, without any domestic transportation, it would be included in the no-domestic mode category. FAF also has seven foreign modes that match the domestic modes minus the no-domestic mode category. FAF has 123 domestic regions, taken from the regions used in the CFS, and eight inter national regions, which are Canada, Mexico, and six groupings based on United Nations definitions. The commodity classifications are from the CFS, which includes 43 two-digit Standard Classification of Transported Goods (SCTG) codes. The CFS collects data on all shipments from a surveyed establishment for an entire week in each of the four quarters of the census year. The CFS reaches a subset of all American estab- lishments, and participation is mandatory. In 2007, the CFS collected data from almost twice as many establishments as in 2002, resulting in about 100,000 samples. Even with this larger sample, the CFS is missing about 30 percent of the total FAF in volume and 32 percent in tons. However, at this point, the data do not include flows that are Out-of-Scope (OOS) or under- counted in the CFS. The OOS commodities include Farm-Based Agricultural Shipments, Fishery, Crude Petroleum, Natural Gas, Municipal Solid Waste, Forestry, Construction, Retail, Services, Household and Business Moves, and Imports. FAF assigns commodity and mode-specific origin-destination flows to these commodities using other methods and many different data sources. In addition, the CFS only captures outbound shipments from domestic firms. There- fore, because it does not include movements of foreign imports, FAF adds foreign trade data, including land crossings between North American countries.
Historical Patterns in Freight Mode Share 17 Mode Shares in Tons As described in the introduction to this report, modal shares vary considerably depending on the metric (tons, ton-miles, value) that is the focus of the analysis. Figure 2 provides estimates of the number of tons moved by each freight mode for the four historical CFS years (1997, 2002, 2007, and 2012) and the four forecast years (2015, 2020, 2025, and 2030). Figure 2 clearly shows the domination of trucks in terms of total tonnage moved. The high level of growth in truck tonnage between 2002 and 2007 slowed considerably from 2007 to 2012, and FAF forecasts continued sluggish growth through 2015 followed by robust growth in future years. Rail is the next largest mode in terms of tonnage, followed by pipelines. Rail exhibited tonnage growth between 1997 and 2002, but has stagnated since, while pipeline moved a stable amount of ton- nage between 1997 and 2002. Figure 3 provides the same set of tonnage data, but in terms of percentages. Historically, truck tonnage has hovered around 70 percent, and FAF projects the truck share to remain in that range. Meanwhile, rail has a share just over 10 percent, while pipelines are just below 10 percent. From 1997, rail has slightly increased its share, while the pipeline share has dipped slightly. Mode Shares in Ton-Miles The distribution by mode is significantly different when analyzed by ton-miles, as average rail and pipeline movements travel longer distances. Figure 4 provides estimates of the number of ton-miles moved by each freight mode for the four historical CFS years (1997, 2002, 2007, and 2012) and the four forecast years (2015, 2020, 2025, and 2030). While truck is still the dominant mode, rail and pipeline capture much larger shares. Although truck steadily increased ton-miles from 1997 to 2012, rail has had a larger increase in ton-miles. Pipelines lost ton-miles between 1997 and 2002, but has stabilized its share since. Figure 5 provides the same set of ton-mile data, but in terms of percentages. Historically, truck ton-miles have hovered around 40 percent, but this mode had lost share slightly by 2012. FAF projects the truck share to grow to 45 over the next decade. Historically, rail has increased its Source: (FHWA 2014a) 0 2 4 6 8 10 12 14 16 18 20 1997 2002 2007 2012 2015 2020 2025 2030 Truck Rail Water Air (includes truck-air) Multiple modes & mail Pipeline Other and unknown Figure 2. Freight transportation by mode in billion tons (1997â2030).
18 Impacts of Policy-Induced Freight Modal Shifts Source: (FHWA 2014a) Truck Rail Water Air (includes truck-air) Multiple modes & mail Pipeline Other and unknown 0% 10% 20% 30% 40% 50% 60% 70% 80% 1997 2002 2007 2012 2015 2020 2025 2030 Figure 3. Freight transportation by mode in percentage of tons (1997â2030). 0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 1997 2002 2007 2012 2015 2020 2025 2030 Source: (FHWA 2014a) Truck Rail Water Air (includes truck-air) Multiple modes & mail Pipeline Other and unknown Figure 4. Freight transportation by mode in trillion ton-miles (1997â2030).
Historical Patterns in Freight Mode Share 19 share of ton-miles by over 5 percent, but FAF forecasts that share to slip in the future. Pipelines have been losing share, and FAF projects that trend to continue. Mode Shares in Values The distribution by mode is again significantly different when analyzed by the value of the goods carried. Figure 6 provides estimates of the value of the goods moved by each freight mode for the four historical CFS years (1997, 2002, 2007, and 2012) and the four forecast years (2015, 2020, 2025, and 2030). Truck still is by far the dominant mode, when analyzed by value, 0% 5% 10% 15% 20% 25% 30% 35% 40% 45% 50% 1997 2002 2007 2012 2015 2020 2025 2030 Source: (FHWA 2014a) Truck Rail Water Air (includes truck-air) Multiple modes & mail Pipeline Other and unknown Figure 5. Freight transportation by mode in percentage of ton-miles (1997â2030). 0.0 5.0 10.0 15.0 20.0 25.0 1997 2002 2007 2012 2015 2020 2025 2030 Source: (FHWA 2014a) Truck Rail Water Air (includes truck-air) Multiple modes & mail Pipeline Other and unknown Figure 6. Freight transportation by mode in value ($, Trillion) (1997â2030).
20 Impacts of Policy-Induced Freight Modal Shifts but rail and pipeline are replaced as the next tier of modes by air and multiple mode (intermodal) shipments. Figure 7 provides the same set of data on the value of goods, but in terms of percentages. FAF projects the truck share to slip slightly over the next decade, with an increase in the share of multiple mode shipments. Mode Share by Distance Mode shares vary considerably by the distance that the freight moves. Figure 8 depicts freight mode shares for ton-miles by distance for 2007. Trucks carry over 80 percent of the ton-miles for shipments of less than 100 miles and for shipments from 100 to 249 miles. For shipments under 750 miles, trucks remain the leader in modal share. Rail is the dominant mode, followed by pipelines for goods moved distances greater than 750 miles, and fewer than 2,000 miles. For shipments over 2,000 miles, there is a fairly even split among rail, water, pipeline, and multiple modes, with truck regaining the largest share. Emissions and Energy Impacts of Freight Mode Share Patterns Modal share studies from the EPA (2006) show that freight greenhouse gas (GHG) emis- sions increased by 46 percent between 1990 and 2003 in the United States. The majority of this increase was due to a switch to less sustainable, more energy intensive modes. GHG emis- sions from 1990 to 2003 exceeded concurrent improvements in the energy efficiency of the modes. GHG emissions of heavy-duty trucks increased by 57 percent, while those of light-duty trucks increased by 51 percent. Non-road modes had either a decrease or a negligible increase in emissions from 1990 to 2003. The EPA (2006) also states that the improvement in energy effi- ciency between 1970 and 1980 is primarily due to the replacement of less fuel-efficient vehicles with new vehicles. 0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 1997 2002 2007 2012 2015 2020 2025 2030 Source: (FHWA 2014a) Truck Rail Water Air (includes truck-air) Multiple modes & mail Pipeline Other and unknown Figure 7. Freight transportation by mode in percentage of value (1997â2030).
Historical Patterns in Freight Mode Share 21 Rail consumes less energy per ton-miles of transportation and utilizes 90 percent and 80 per- cent less energy than truck and ships, respectively (in terms of British thermal unit). According to Freight Rail Works, a member of the Association of American Railroads that operates over 140,000 miles of rail network across North America, the United States transports one-third of its exports by rail and approximately 40 percent of intercity freight volume (2014). Freight rail contributes 2.3 percent to total GHG emissions caused by the transportation sector, and the trucking industry contributes 22.4 percent. This relationship between mode share and emis- sions in the United States is explained in detail in the section below. The mode share of all commercial freight activity in the United States in terms of tons of commodity transported for the years 1993, 1997, and 2002 is displayed in Table 4. The table shows that for those three years, trucking maintained its position as the predominant mode in terms of weight of commodity transported, while air was the most negligible of the modes. In terms of tons, there was not a significant change in the mode share for truck and rail over the period. For truck, there was an increase in mode share by 9 percent between 1993 and 1997, Source: (Strocko et al. 2013) 100% 90% 80% 70% 60% 50% 40% 30% 20% 10% 0% M od e Sh ar e Below 100 100-249 250-499 500-749 750-999 1,000-1,499 1,500-2,000 Over 2,000 Average Distance Band (miles) Other/Unknown Multiple Modes & Mail Water Truck Pipeline Air Rail Figure 8. Mode share of freight ton-miles by distance band (2007). 1993 1997 2002 1993â97 1997â2002 Truck 54.47 59.48 58.15 9.21 -2.24 Rail 11.83 10.85 11.98 -8.29 10.40 Water 15.93 15.36 14.83 -3.62 -3.45 Air (includes truck and air) 0.05 0.07 0.07 40.00 0.00 Pipeline 11.94 9.70 10.47 -18.77 7.92 Multimodal combinations* 1.73 1.53 1.35 -11.64 -11.56 Other and unknown modes 4.05 2.96 3.16 -26.81 6.64 Mode of Transportation Mode Share (Tons) % Change in the Freight Mode Share Data source: (U.S. DOT 2004) * Multimodal combinations include truck and rail, truck and water, and postal and courier services. Table 4. Freight mode share distribution (tons).
22 Impacts of Policy-Induced Freight Modal Shifts and a decrease by 2 percent from 1997 to 2002. The rail mode share decreased by 8 percent between 1993 and 1997, and increased by 10 percent between 1997 and 2002. The share of tonnage of commodity transported by water and multimodal combinations decreased by 3 percent and 11 percent, respectively, in both the 1993 to 1997 and 1997 to 2002 periods. This information is based on CFS data plus additional estimates from the Bureau of Transportation Statistics (BTS). Table 5 shows the mode shares in terms of ton-miles of commodities transported in 1993, 1997, and 2002. In 1993, all predominant modesâtruck, rail, and waterwaysâhad almost equal mode shares, around 25 percent. The air mode had the least mode share, less than 0.5 percent from 1993 to 2002. In 1997, the mode share of waterways decreased to 20 percent, while that of truck and rail increased to 28 percent and 27 percent, respectively. Although the air mode share is 0.37 percent, there was a 50 percent increase in the mode share of air between 1993 and 1997. By 2002, the mode share of truck increased to 32 percent, while the mode share of rail remained constant, close to 27 percent from 1993 to 2002. In the columns showing the percentage change in the share of different modes, it can be seen that the rate of increase of the truck mode share grew; 10.94 percent growth from 1993 to 1997 and 13 percent growth between 1997 and 2002. The growth in rail mode decreased, from nearly 3 percent between 1993 and 1997 to 2 percent between 1997 and 2002. A comparison of Tables 4 and 5 shows that the higher the mode share for rail in terms of ton-miles, the lower the mode share in terms of weight. This indicates that rail is used to carry less cargo weight longer distances. Water, air, pipeline, and multimodal combinations show trends similar to that of rail: less weight carried larger distances. The truck mode, on the other hand, is used to transport more cargo smaller distances. Figure 9 depicts the overall percentage change in mode share between 1993 and 2002 in terms of tons transported. The air mode grew by 23 percent, followed by the truck mode, which grew by nearly 7 percent. Rail grew by just 1.24 percent. Waterway mode share by weight decreased by 7 percent. The mode share of multimodal combinations and other modes decreased by around 20 percent each. The growth in the truck mode share is compensated for by the drastic decrease in waterways and other modes. Multimodal combinations increased between 1993 and 1997, but decreased between 1997 and 2002. Figure 10 depicts the overall percentage change in mode share between 1993 and 2002 in terms of ton-miles of cargo transported. The air mode grew by 32 percent, followed by the truck mode, which grew by 26 percent. The rail and pipeline grew by less than 5 percent, and waterways and other modes decreased by 33 percent. The mode share of multi- modal combinations increased by 10 percent from 1993 to 2002. 1993 1997 2002 1993â97 1997â2002 Truck 25.59 28.39 32.15 10.94 13.23 Rail 26.51 27.29 27.82 2.95 1.93 Water 24.25 20.84 16.27 -14.10 -21.89 Air (includes truck and air) 0.25 0.37 0.33 49.91 -12.08 Pipeline 16.29 15.79 16.71 -3.08 5.83 Multimodal combinations* 4.55 5.43 5.03 19.35 -7.49 Other and unknown modes 2.54 1.88 1.70 -26.13 -9.59 Mode Mode Share (Ton-Miles) % Change in the Freight Mode Share Data source: (U.S. DOT 2004) * Multimodal combinations include truck and rail, truck and water, and postal and courier services. Table 5. Freight mode share distribution (ton-miles).
Historical Patterns in Freight Mode Share 23 A comparison of the data in Figures 9 and 10 shows that truck mode share by weight increased by 7 percent, while truck mode share by ton-miles increased by about 25 percent; in other words, the mode share by ton-miles increased more than the mode share by weight. This indicates that more miles were traveled by truck in 2002 than were traveled in 1993, with less increase in the weight carried. The rail mode also had less increase in weight, but more miles traveled. Waterways and other modes had decreases in both weight and distance. The airline industry had increases in both weight and distance, nearly of equal margins. Multimodal combinations and pipeline are exceptional, as the mode share by weight decreased for both, while increases in the distance of transportation led to increases in the mode share in the ton-miles traveled. This analysis is supported by Greenhouse Gas Emissions from the U.S. Transportation Sector: 1990â2003 (EPA 2006), which states that the increase in the haulage of heavy-duty trucks led to an increase in vehicle miles traveled (VMT) of 48 percent from 1990 to 2003. The data for Tables 4 and 5, and Figures 9 and 10 are based on 1993, 1997, and 2002 CFS data and estimates from BTS. Of note is that the rail mode had less increase in both weight and ton- miles compared to the truck mode, which indicates a greater expansion of roads than railways. The mode share in ton-miles per CFS data only for 1997, 2002, 2007, and 2012 is presented in Table 6. The mode share of truck increased from 1997 to 2007 and decreased from 2007 to 2012. Rail mode share increased between 2007 and 2012. This trend could be due to the economic downturn and rising fuel prices during that period (see Figure 11). Data source: (U.S. DOT 2004) 6.77 1.24 -6.94 23.19 -12.34 -21.85 -21.95 -25 -20 -15 -10 -5 0 5 10 15 20 25 30 T ruck R ail W ater A ir (includes truck and air) Pipeline M ultim odal com binations O ther m odes Figure 9. Percentage change in the freight mode share (tons) from 1993 to 2002. Data source: (U.S. DOT 2004) 25.62 4.93 -32.90 31.80 2.56 10.41 -33.21-40 -30 -20 -10 0 10 20 30 40 T ruck R ail W ater A ir (includes truck and air) Pipeline M ultim odal com binations O ther m odes Figure 10. Percentage change in the freight mode share (ton-miles) from 1993 to 2002.
24 Impacts of Policy-Induced Freight Modal Shifts The impact of the recession and fuel prices can also be observed in the total VMT in the United States. Figure 11 shows the total VMT from 1970 to 2012. The VMT of total vehicles increased at a constant rate of 2.4 percent from 1970 to 2012. There is a drop in VMT from 3,117,292 to 3,063,059 million miles between 2007 and 2008. VMT further declined to 2,956,816 million miles in 2009, and from 2009 to 2012, the total VMT remained more or less constant. Figure 12 gives the modal distribution of VMT between 1970 and 2012. Passenger cars are the predominant mode in VMT throughout the period, although the passenger car mode share decreased from 80 percent to 50 percent between 1970 and 2012. The share of two-axle, four-tire trucks increased tremendously: from 10 percent in 1970 to 40 percent in 2012. Single- unit and combination trucks increased by 1 to 2 percent over the same period. This analysis is also supported by Greenhouse Gas Emissions from the U.S. Transportation Sector: 1990â2003 (EPA 2006), which states that sales of light-duty vehicles increased from 1988 to 2003, leading to more VMT. In 2002, light-duty vehicle sales surpassed the sales of passenger cars. It is important to consider the different types of trucks when evaluating the modal distribu- tion of freight. Table 7 lists the eight truck classes, categorized by the gross vehicle weight rating of each vehicle, and lists a few examples of vehicles belonging to each class. Classes 1 and 2 are called light trucks while Classes 3 through 8 are categorized as heavy trucks. It can be observed that lightweight vehicles contribute more to emissions than heavy trucks (see Figure 16). Figure 13 shows the total emissions of carbon dioxide (CO2) from all sectors from 1990 to 2012. Total emissions increased from 1990 to 2007, then decreased sharply in 2008. From 2007 Mode/Year 1997 2002 2007 2012 Trucka 38.46 40.02 40.13 38.08 Rail 38.42 40.21 40.18 44.51 Water 9.83 9.01 4.70 6.27 Air (includes truck and air) 0.23 0.18 0.13 0.19 Pipelineb 2.62 1.98 1.39 1.57 Multiple modes 7.68 7.19 12.46 9.36 Other and unknown modes 2.76 1.41 1.01 0.01 Data source: (Oak Ridge National Laboratory 2014a) aTruck as single mode (for-hire/private truck); bExcludes most shipments of crude oil by pipeline Table 6. Mode share in ton-miles based on CFS data (1997, 2002, 2007, and 2012). Data source: (Oak Ridge National Laboratory 2014a) 0 500,000 1,000,000 1,500,000 2,000,000 2,500,000 3,000,000 3,500,000 19 70 19 72 19 74 19 76 19 78 19 80 19 82 19 84 19 86 19 88 19 90 19 92 19 94 19 96 19 98 20 00 20 02 20 04 20 06 20 08 20 10 20 12 V M T in m ile s Year Figure 11. Vehicle miles traveled by all vehicles in the United States (1970â2012).
Historical Patterns in Freight Mode Share 25 Data source: (Oak Ridge National Laboratory 2014a) 19 70 19 72 19 74 19 76 19 78 19 80 19 82 19 84 19 86 19 88 19 90 19 92 19 94 19 96 19 98 20 00 20 02 20 04 20 06 20 08 20 10 20 12 0.0% 10.0% 20.0% 30.0% 40.0% 50.0% 60.0% 70.0% 80.0% 90.0% Pe rc en ta ge s ha re o f to ta l V M T Year Motorcycles Cars Two-axle, four-tire trucks Single-unit trucks Figure 12. Mode share of VMT from 1970 to 2012. Class Weight category (lb) Examples 1 6,000 or Less Minivan, Cargo Van, SUV, Pickup Truck 2 6,001â10,000 Minivan, Cargo Van, Full-Size Pickup, Step Van 3 10,001â14,000 Walk-In, Box Truck, City Delivery, Heavy-Duty Pickup 4 14,001â16,000 Large Walk-In, Box Truck, City Delivery 5 16,001â19,500 Bucket Truck, Large Walk-In, City Delivery 6 19,501â26,000 Beverage Truck, Single-Axle, School Bus, Rack Truck 7 26,001â33,000 Refuse, Furniture, City Transit Bus, Truck Tractor 8 33,001 or Over Cement Truck, Truck Tractor, Dump Truck, Sleeper Source: (Oak Ridge National Laboratory 2014b) Table 7. Truck classes and examples. Data source: (EPA 2014) 5500 6000 6500 7000 7500 C O 2 em is si on s in m ill io n m et ri c to ns (M T ) Year 19 90 19 92 19 94 19 96 19 98 20 00 20 02 20 04 20 06 20 08 20 10 20 12 Figure 13. Total CO2 emissions in million metric tons (MT) (1990â2012).
26 Impacts of Policy-Induced Freight Modal Shifts to 2012 the total emissions showed a huge decline. This could be due to improvements in fuels and vehicle technologies, as well as to the economic recession in 2008 followed by a steep rise in fuel prices (Oak Ridge National Laboratory 2014b). Figure 14 shows CO2 emissions in MT from various sectors from 1990 to 2012. The trans- portation sector is the second major contributor to emissions after electricity generation. The emissions from the industrial sector decreased from 1990 to 2012, while the emissions from the agriculture, commercial and residential sectors remain more or less constant through that period. There was a steep decline in CO2 emissions from the transportation sector from 2008 on. Figure 15 shows the transportation sectorâs contribution to total CO2 emissions from 1990 to 2012. The emission share of the transportation sector has been steadily increasing, except for the period of 2008 to 2010. The transportation sector contributed 25 percent of total CO2 emissions in 1990, while in 2012 the same sector contributed more than 28 percent of CO2 emissions. The shift from low-emission modes (rail) to high-emission modes (truck) in the past 2 years is one of the major reasons behind this growth (Freight Rail Works 2014). Data source: (EPA 2014) 0 500 1000 1500 2000 2500 3000 C O 2 em is si on s in m ill io n M T Year Electricity generation Transportation Industry Agriculture Commercial Residential 19 90 19 91 19 92 19 93 19 94 19 95 19 96 19 97 19 98 19 99 20 00 20 01 20 02 20 03 20 04 20 05 20 06 20 07 20 08 20 09 20 10 20 11 20 12 Figure 14. CO2 emissions from various sectors (1990â2012). Data source: (EPA 2014) 22 23 24 25 26 27 28 29 19 90 19 91 19 92 19 93 19 94 19 95 19 96 19 97 19 98 19 99 20 00 20 01 20 02 20 03 20 04 20 05 20 06 20 07 20 08 20 09 20 10 20 11 20 12 % s ha re o f C O 2 em is si on s (M ill io n M T ) Year Figure 15. Transportation sectorâs share of total CO2 emissions (1990â2012).
Historical Patterns in Freight Mode Share 27 Figure 16 shows the contribution of each mode, including passenger transport, to the overall GHG emissions by transportation sector in 2003. Table 5 (2002) and Figure 16 (2003) show that the air mode, with 0.33 percent of the modal share in ton-miles, contributes 9 percent of the GHG emissions, while the truck mode, with 32 percent of the mode share, contributes nearly 50 percent of the total emissions. It is interesting to see that rail, with around 27 percent of the mode share in ton-miles, contributes just 2 percent of the emissions, and waterways, with 16 percent of the mode share, contribute just 3 percent of the total emissions. This proves how large a role mode shift can play in contributing to, or reducing, GHG emissions of the trans- portation sector. The studies by Oak Ridge National Laboratory (2014a, 2014b) confirm the importance of mode share in emissions. Figure 17 shows the contribution of transportation and highway vehicles to the total emis- sions of carbon monoxide (CO), nitrogen oxides (NOx), volatile organic compounds (VOCs), and particulate matter of (1) less than 2.5 microns and (2) less 10 microns (PM-2.5 and PM-10, respectively). Clearly, the highway sector contributes most of the emissions in transportation. Especially in terms of CO emissions, the transportation sector accounted for nearly 80 percent of the emissions in 1970, 1980, 1990, and 2000. There is a drop in CO emissions from the transpor- tation sector in 2010 and 2013 to nearly 60 percent. Almost 50 percent of NOx, 20 to 30 percent of VOCs, 6 to 7 percent of PM-2.5 emissions, and 2 percent of PM-10 emissions are from the transportation sector. In 1995, there was a sudden rise in PM-10 emissions from the transporta- tion sector to 10 percent. Figure 17 also indicates that the non-highway sectorâs contribution to these emissions is less than that of the highway sector. Table 5 and Figure 17 show that highway (trucks) with 25 to 32 percent of mode share in ton-miles from 1993 to 2002, contributed nearly 80 percent, 60 percent and 50 percent of the emissions of CO, NOx, and VOC, respectively, during that period. Despite the increase in mode share and ton-miles traveled by trucks, total emissions from the transportation sector have declined. Between 2002 and 2013, CO emissions declined by 47 percent, NOx emissions declined by 49 percent, VOC emissions declined by 41 percent, and PM-10 emissions declined by 39 percent. This could be due to technological improvements in vehicles, the recession, and fuel price changes in 2008 (Oak Ridge National Laboratory 2014b). In addition to increased emissions, inefficiencies in mode share or the shift toward trucks causes other externalities, including accidents, congestion, noise, pavement deterioration, and greater consumption of natural resources such as energy and fuel by the transportation sector (McAuley 2010). Source: (EPA 2014) Passenger cars 36% Light trucks 28% Heavy-Duty 19% Aircraft 9% Waterways 3% Pipelines 2% Rail 2% Lubricants 1% Figure 16. Mode share of GHG emissions (million MT) by transportation sector in 2003.
28 Impacts of Policy-Induced Freight Modal Shifts Figure 18 shows the total energy consumed by various sectors from 1970 to 2012 in trillion British Thermal Units (BTUs). Transportation is the second major consumer of energy after the electric power sector. Total energy consumption in the United States increased steadily from 1970 to 2007 and declined slightly from 2008 to 2012. The mode share of transporta- tion in energy consumption was steadily increasing between 24 percent and 28 percent from 1970 to 2012. In 2008, there was a decrease in energy consumption in the electric power and transportation sectors. The source of energy explains the sustainability and efficiency of its consumption; the more renewable and pollution-free the energy source, the more sustainable the system will be. So, it is important to look into how different sources of energy are distrib- uted across the energy consumption spectrum of the transportation sector. Figure 19 explains the energy consumed by the transportation sector from various energy sources. The total energy consumed by the transportation sector increased from 1970 to 2012, with little variation. Between 2007 and 2012, consumption decreased. The use of biomass and electricity also increased from 2006 to 2012. This could be due to the recession in 2008, followed by the fuel price increase to $90 per barrel from $35 per between 2004 and 2008 (Oak Ridge National Data source: (Oak Ridge National Laboratory 2014a) 0 20 40 60 80 100 1970 1980 1990 2000 2010 2013 P er ce nt CO 0 2 4 6 8 10 12 1990 1995 2000 2005 2010 2013 P er ce nt PM-2.5 0 20 40 60 80 1970 1980 1990 2000 2010 2013 P er ce nt NOx 0 10 20 30 40 50 60 1970 1980 1990 2000 2010 2013 P er ce nt VOCs 0 2 4 6 8 10 12 1990 1995 2000 2005 2010 2013 P er ce nt PM-10 Transportation total Highway vehicles Figure 17. Contribution of transportation and highway mode to total emissions.
Data Source: (U.S. Energy Information Administration 2014) 0 5,000 10,000 15,000 20,000 25,000 30,000 35,000 40,000 45,000 19 70 19 72 19 74 19 76 19 78 19 80 19 82 19 84 19 86 19 88 19 90 19 92 19 94 19 96 19 98 20 00 20 02 20 04 20 06 20 08 20 10 20 12 Residential sector Commercial sector Industrial sector Transportation sector Electric power sector 0 20,000 40,000 60,000 80,000 100,000 120,000 19 70 19 72 19 74 19 76 19 78 19 80 19 82 19 84 19 86 19 88 19 90 19 92 19 94 19 96 19 98 20 00 20 02 20 04 20 06 20 08 20 10 20 12 Total energy consumption Transportation sector Figure 18. Energy consumption (in trillion BTU) of different sectors (1970â2012). Data Source: (U.S. Energy Information Administration 2014) 0 5,000 10,000 15,000 20,000 25,000 30,000 B T U ( tr ill io n) Coal Natural Gas Petroleum Biomass Energy 20 12 20 10 20 08 20 06 20 04 20 02 20 00 19 98 19 96 19 94 19 92 19 90 19 88 19 86 19 84 19 82 19 80 19 78 19 76 19 74 19 72 19 70 Figure 19. Energy consumed by the transportation sector from different sources (1970â2012).
30 Impacts of Policy-Induced Freight Modal Shifts Laboratory 2014b). The important point is that petroleum is the source of energy consumed by the transportation sector; almost 95 percent of the total energy consumed by the transportation sector is from petroleum. Very little energy for transportation is derived from sustainable or environmentally friendly sources such as biomass (1 percent) and electricity (0.1 percent). Figure 20 illustrates the energy consumption share of various modes from 1970 to 2012. Highway vehicles, which include passenger vehicles, consumed 81.4 percent of the energy con- sumed by the transportation sector in 2012 (Oak Ridge National Laboratory 2014a). The rail mode share includes both freight and passenger transportation. Table 5 shows that the freight mode share of rail was nearly 26 to 27 percent of ton-miles from 1993 until 2002. A compari- son of this with Figure 20 shows that the rail mode contributed 26 percent of the ton-miles of freight transportation, but consumed 2 to 3 percent of the total energy consumed by the trans- portation sector and contributed just 2 percent of the total GHG emissions (See Figure 16). In addition, Figure 20 shows that the light truck contribution to energy consumption increased from 10 percent to 30 percent over the period of 1970 to 2012. This could also be attributed to the increase in the VMT of light trucks, as explained in Figure 12. Energy consumption depends on the number of miles traveled; therefore, comparing Figure 20 with Figure 12 it can be observed that the VMT share of heavy trucks (the sum of single unit and combination trucks) is nearly 10 percent, which contributes 20 percent of the energy consumption, whereas light trucks, with nearly 40 percent of the VMT share, contribute 30 percent of the energy consumption. This is due to increased fuel efficiency in light trucks (EPA 2006). The energy consumption of heavy trucks increased from 10 percent to 20 percent from 1970 to 2012, primarily due to Class 7 and 8 vehicles. The share of energy consumption by trucks categorized as Classes 3 through 6 increased from 2 percent to 5 percent, while that of Classes 7 and 8 increased from 8 percent to 17 percent. An explanation for the share of energy consumption among medium/heavy trucks, Classes 3 through 8, follows. Figure 21 shows the mode share (in total number of vehicles) and energy use share (in BTU) of Class 3â8 trucks in 2002. Class 8 vehicles, which constituted 41 percent of heavy trucks, Data source: (Oak Ridge National Laboratory 2014a) Notes: (1) Light trucks include pickups, minivans, sport-utility vehicles, and vans. (2) Heavy trucks represent the sum of Class 3â6 trucks and Class 7â8 trucks. (3) Passenger road mode includes cars, buses, and motorcycles. 0 10 20 30 40 50 60 19 70 19 72 19 74 19 76 19 78 19 80 19 82 19 84 19 86 19 88 19 90 19 92 19 94 19 96 19 98 20 00 20 02 20 04 20 06 20 08 20 10 20 12 Pe rc en ta ge o f en er gy c on su m pt io n Year Passenger road Light trucks Heavy trucks Air Water Rail Class 3-6 trucks Class 7-8 trucks Figure 20. Energy consumption share by mode of transportation (1970â2017).
Historical Patterns in Freight Mode Share 31 accounted for 78 percent of the total energy use by heavy trucks. According to the Oak Ridge National Laboratory (2014b), Class 3â6 trucks are economical in fuel consumption, but they are used for shorter distance trips. The fact that these are heavy trucks making shorter trips is also represented by the low VMT values from Figure 12. Single-axle, four-tire trucks constitute the majority of VMT by all modes. Light trucks caused more GHG emissions (28 percent) than did heavy trucks (19 percent) (see Figure 16). Clearly, light trucks had higher VMT and more energy consumption and emissions than heavy trucks. Among heavy trucks, Class 8 trucks contribute the majority of mode share in number of vehicles and energy consumption. A similar pattern is observed in the consumption of petroleum by various transportation modes from 1970 to 2012 (see Figure 22). Highway vehicles consumed 85.9 percent of the total petroleum consumed by the transportation sector (Oak Ridge National Laboratory 2014a), with the most consumption by light trucks, followed by heavy trucks. Class 7â8 trucks were the lead- ing consumers of petroleum among heavy trucks. Railâs share of petroleum consumption was Data Source: (Oak Ridge National Laboratory 2014b) 0% 20% 40% 60% 80% 100% Class-3 Class-4 Class-5 Class-6 Class-7 Class-8 Mode share Energy use share Figure 21. Mode share and energy use share of heavy trucks (Classes 3â8) in 2002. Data source: (Oak Ridge National Laboratory 2014a) Note: (1) Light trucks include pickups, minivans, sport-utility vehicles and vans. (2) Heavy trucks represent the sum of Class 3â6 trucks and Class 7â8 trucks. (3) Passenger road mode includes cars, buses, and motorcycles. 0 10 20 30 40 50 60 70 19 70 19 72 19 74 19 76 19 78 19 80 19 82 19 84 19 86 19 88 19 90 19 92 19 94 19 96 19 98 20 00 20 02 20 04 20 06 20 08 20 10 20 12 Pe rc en ta ge o f pe tr ol eu m c on su m pt io n Year Passenger road Light trucks Heavy trucks Air Water Rail Class 3-6 trucks Class 7-8 trucks Figure 22. Petroleum consumption share by mode of transportation (1970â2012).
32 Impacts of Policy-Induced Freight Modal Shifts nearly 2 percent of total petroleum consumption (Figure 22). Waterways were similarly efficient; with a contribution of 16 to 20 percent of ton-miles, waterwaysâ share of the total energy and petroleum consumption of transportation is only 4 to 5 percent. Figures 20 and 22 show that the passenger car contribution to energy and petroleum consumption has decreased from 60 per- cent to 30 percent over the period 1970â2012. Overall, transportation in the United States became more efficient from 1970 to 2009. Between 1970 and 2009, the fuel used by all vehicles per mile declined from nearly 80 gallons to 55 gallons per thousand miles. The production-weighted average annual carbon footprint for light vehicles (including vans, special utility vehicles, and trucks) dropped by 40 percent from 1975 to 2013 (Oak Ridge National Laboratory 2014a). So, transportation overall has improved its functional efficiency. The externalities discussed so far can be attributed to the combined impact of higher economic activity, changes in costs (vehicle and fuel), and more VMT and modal distribution. Since the national economy and fuel prices influence modal distribution and, by extension, such transportation externalities as pollution, GHG emissions, and energy consumption, it is important to look at economic growth and fuel price changes in the United States. Figure 23 shows the economic growth rate and fuel price changes in the United States from 1970 to 2012. Changes in oil prices affected the markets five times (1973 to 1974, 1979 to 1980, 1990 to 1991, 1999 to 2000, and 2008) in 30 years. The rise in oil prices can be observed just after the recession that began in 2008. The reduction in the total emissions of CO, NOx, and VOCs, in the energy and petroleum consumed by the transportation sector, and in the total VMT in the year of 2008 can all be attributed to the economic downturn and rising fuel prices, as described previously. Data source: (Oak Ridge National Laboratory 2014a) -4% -2% 0% 2% 4% 6% 8% $0 $20 $40 $60 $80 $100 $120 19 70 19 72 19 74 19 76 19 78 19 80 19 82 19 84 19 86 19 88 19 90 19 92 19 94 19 96 19 98 20 00 20 02 20 04 20 06 20 08 20 10 20 12 G D P G ro w th R at e O il P ri ce Year Oil Price per Barrel (2009 $) GDP Growth Rate Figure 23. Price of oil and gross domestic product (GDP) growth rate (1970â2012).