Summary

Liquid fuel consumption by medium- and heavy-duty vehicles (MHDVs) represents 26 percent of all U.S. liquid transportation fuels consumed and has increased more rapidly—in both absolute and percentage terms—than consumption by other sectors. In early recognition of these trends, which are forecast to continue until 2035 (DOE, EIA, 2009), the Energy Independence and Security Act of 2007 (EISA; Public Law 110-140, Dec. 19, 2007), Section 108, was passed, requiring the U.S. Department of Transportation (DOT), for the first time in history, to establish fuel economy standards for MHDVs. In December 2009 the U.S. Environmental Protection Agency (EPA) formally declared that greenhouse gas (GHG) emissions endanger public health and the environment within the meaning of the Clean Air Act, a decision that compels EPA to consider establishing first-ever GHG emission standards for new motor vehicles, including MHDVs. If the United States is to reduce its reliance on foreign sources of oil, and reduce GHG emissions from the transportation sector, it is important to consider how the fuel consumption of MHDVs can be reduced.

Following the passage of EISA, the National Research Council appointed the Committee to Assess Fuel Economy Technologies for Medium- and Heavy-Duty Vehicles. The committee considered approaches to measuring fuel economy (the committee uses fuel consumption), assessed current and future technologies for reducing fuel consumption, addressed how such technologies may be practically implemented in vehicles, discussed the pros and cons of approaches to improving the fuel efficiency of moving goods as opposed to setting vehicle fuel consumption standards, and identified potential costs and other impacts on the operation of MHDVs (see Chapter 1 and Appendix A for the complete statement of task).

The legislation also requires DOT’s National Highway Traffic Safety Administration (NHTSA) to conduct its own study on the fuel consumption of commercial medium- and heavy-duty highway vehicles and work trucks and then to establish a rulemaking to implement a commercial medium-and heavy-duty on-highway and work-truck fuel efficiency improvement program.

The organization of this Summary follows that of the report’s chapters: Chapter 1 provides background; Chapter 2 provides vehicle fundamentals; Chapter 3 surveys the current U.S., European, and Asian approaches to fuel economy and regulations; Chapters 4 and 5 review and assess technologies to reduce fuel consumption; Chapter 6 assesses direct and indirect costs and benefits of integrating fuel consumption reduction technologies into vehicles; Chapter 7 presents a review of potential unintended consequences and the alternative nontechnology approaches to reducing fuel consumption; and Chapter 8 reviews options for regulatory design. The Summary presents the committee’s major findings and recommendations from each chapter; fuller discussion and additional findings are found in the report.

VEHICLE FUNDAMENTALS, FUEL CONSUMPTION, AND EMISSIONS

Medium- and heavy-duty trucks, motor coaches, and transit buses, Class 2b through Class 8, are used in every sector of the economy. The purposes of these vehicles range from carrying passengers to moving goods. For some vehicles and driving cycles this simple relationship breaks down (as with a bucket truck, which carries one or two passengers but delivers no freight). It brings services and capability (the bucket, tools, and spare parts) to a job site. This results in a broad range of varying duty cycles, from high-speed operation on highways with few stops to lower-speed urban operation with many stops per mile. For the purposes of estimating fuel consumption benefits of various technologies in this report, the committee examined seven different types of vehicles and made assumptions about the duty cycles that would characterize their operations: (1) tractor trailer, (2) Class 6 box truck, (3) Class 6 bucket truck, (4) refuse truck, (5) transit bus, (6) motor coach, and (7) pickup/van. When DOT promulgates standards for fuel consumption, it will have to



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Summary Liquid fuel consumption by medium- and heavy-duty and heavy-duty on-highway and work-truck fuel efficiency vehicles (MHDVs) represents 26 percent of all U.S. liq- improvement program. uid transportation fuels consumed and has increased more The organization of this Summary follows that of the r apidly—in both absolute and percentage terms—than report’s chapters: Chapter 1 provides background; Chapter 2 consumption by other sectors. In early recognition of these provides vehicle fundamentals; Chapter 3 surveys the current trends, which are forecast to continue until 2035 (DOE, EIA, U.S., European, and Asian approaches to fuel economy and 2009), the Energy Independence and Security Act of 2007 regulations; Chapters 4 and 5 review and assess technologies (EISA; Public Law 110-140, Dec. 19, 2007), Section 108, to reduce fuel consumption; Chapter 6 assesses direct and was passed, requiring the U.S. Department of Transportation indirect costs and benefits of integrating fuel consumption (DOT), for the first time in history, to establish fuel economy reduction technologies into vehicles; Chapter 7 presents a standards for MHDVs. In December 2009 the U.S. Envi- review of potential unintended consequences and the alter- ronmental Protection Agency (EPA) formally declared that native nontechnology approaches to reducing fuel consump- greenhouse gas (GHG) emissions endanger public health and tion; and Chapter 8 reviews options for regulatory design. the environment within the meaning of the Clean Air Act, a The Summary presents the committee’s major findings and decision that compels EPA to consider establishing first-ever recommendations from each chapter; fuller discussion and GHG emission standards for new motor vehicles, including additional findings are found in the report. MHDVs. If the United States is to reduce its reliance on foreign sources of oil, and reduce GHG emissions from the VEHICLE FUNDAMENTALS, FUEL CONSUMPTION, transportation sector, it is important to consider how the fuel AND EMISSIONS consumption of MHDVs can be reduced. Following the passage of EISA, the National Research Medium- and heavy-duty trucks, motor coaches, and tran- Council appointed the Committee to Assess Fuel Economy sit buses, Class 2b through Class 8, are used in every sector Technologies for Medium- and Heavy-Duty Vehicles. of the economy. The purposes of these vehicles range from The committee considered approaches to measuring fuel carrying passengers to moving goods. For some vehicles and economy (the committee uses fuel consumption), assessed driving cycles this simple relationship breaks down (as with a current and future technologies for reducing fuel consump- bucket truck, which carries one or two passengers but deliv- tion, addressed how such technologies may be practically ers no freight). It brings services and capability (the bucket, implemented in vehicles, discussed the pros and cons of ap- tools, and spare parts) to a job site. This results in a broad proaches to improving the fuel efficiency of moving goods as range of varying duty cycles, from high-speed operation on opposed to setting vehicle fuel consumption standards, and highways with few stops to lower-speed urban operation identified potential costs and other impacts on the operation with many stops per mile. For the purposes of estimating fuel of MHDVs (see Chapter 1 and Appendix A for the complete consumption benefits of various technologies in this report, statement of task). the committee examined seven different types of vehicles The legislation also requires DOT’s National Highway and made assumptions about the duty cycles that would Traffic Safety Administration (NHTSA) to conduct its own characterize their operations: (1) tractor trailer, (2) Class study on the fuel consumption of commercial medium- and 6 box truck, (3) Class 6 bucket truck, (4) refuse truck, (5) heavy-duty highway vehicles and work trucks and then to transit bus, (6) motor coach, and (7) pickup/van. When DOT establish a rulemaking to implement a commercial medium- promulgates standards for fuel consumption, it will have to 

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 TECHNOLOGIES AND APPROACHES TO REDUCING THE FUEL CONSUMPTION OF MEDIUM- AND HEAVY-DUTY VEHICLES address the duty cycles that characterize different types of metric and be based on using an average (or typical) payload vehicles and their wide range of applications. based on national data representative of the classes and duty The fundamental engineering metric for measuring the cycle of the vehicle. Standards might require different values fuel efficiency of a vehicle is fuel consumption, the amount of LSFC due to the various functions of the vehicle classes of fuel used, assuming some standard duty or driving cycle, e.g., buses, utility, line haul, pickup, and delivery. Regula- to deliver a given transportation service, for example, the tors need to use a common procedure to develop baseline amount of fuel a vehicle needs to go a mile or the amount LSFC data for various applications, to determine if separate of fuel needed to transport a ton of goods a mile. For light- standards are required for different vehicles that have a com- duty vehicles (cars and light trucks), the corporate average mon function. Any data reporting or labeling should state an fuel economy (CAFE) program uses miles per gallon (mpg). LSFC value at specified tons of payload. This measure, although derived from measurements of fuel consumption in gallons/mile, is not the appropriate measure COMPARING THE REGULATORY APPROACHES for MHDVs, since these vehicles are designed to carry loads OF THE UNITED STATES, JAPAN, AND EUROPEAN in an efficient and timely manner. A partially loaded tractor COMMUNITY trailer would consume less fuel per mile than a fully loaded truck, but this would not be an accurate measure of the fuel Although a CAFE regulatory program has been imple- efficiency of moving goods. However, normalizing fuel con- mented for light-duty vehicles, where the responsibility for sumption by the payload and using the calculation of gallon/ the manufacture and certification of vehicles is well defined ton-mile—the load-specific fuel consumption (LSFC)—the and the configurations of cars and light trucks for sale are fully loaded truck would have a much lower LSFC number well defined and of limited number, the MHDV world is than the partially loaded truck, reflecting the ability of the much more complicated. There are literally thousands of truck to accomplish the task of delivering goods. different configurations for vehicles, including bucket trucks, pickup trucks, garbage trucks, delivery vehicles, and long- haul tractor trailers. Their duty cycles vary greatly. Some Major Findings and Recommendations— stop and go every few seconds; others spend most of their Chapters 1 and 2: Introduction and Fundamentals time at highway speeds. Furthermore, the party responsible Finding 2-1. Fuel consumption (fuel used per distance trav- for the final truck configuration is often not well defined. eled; e.g., gallons per mile) has been shown to be the funda- For example, a body builder (vehicle integrator) may be the mental metric to properly judge fuel efficiency improvements manufacturer of record, but the body builder may not design from both engineering and regulatory viewpoints, including or even specify the chassis and power train. For tractor-trailer yearly fuel savings for different technology vehicles. combinations, the tractor and trailer are always made and often owned by different companies, and a given tractor may Finding 2-2. The relationship between the percent improve- pull hundreds of different trailers of different configurations ment in fuel economy (FE) and the percent reduction in fuel over its life. Many trucks are custom made, literally one of consumption (FC) is nonlinear; e.g., a 10 percent increase in a kind. FE (miles per gallon) corresponds to a 9.1 percent decrease Even though the regulation of such vehicles will be much in FC, whereas a 100 percent increase in FE corresponds more complicated than it is for light-duty vehicles, the barri- to a 50 percent decrease in FC. This nonlinearity leads to ers are not insurmountable. Safety and emission regulations widespread consumer confusion as to the fuel-savings po- have been implemented, and regulations for fuel consump- tential of the various technologies, especially at low absolute tion in medium- and heavy-duty trucks already exist in Japan values of FE. and are under development by the European Commission. California is building on the EPA’s SmartWay Partnership Finding 2-3. MHDVs are designed as load-carrying ve- to implement its own approach to regulating truck fuel hicles, and consequently their most meaningful metric of consumption. fuel efficiency will be in relation to the work performed, such as fuel consumption per unit payload carried, which Major Findings and Recommendations— is load-specific fuel consumption (LSFC). Methods to in- Chapter 3: Current Regulatory Approaches crease payload may be combined with technology to reduce Finding 3-1. Although it took years of development and fuel consumption to improve LSFC. Future standards might require different values to accurately reflect the applications substantial effort, regulators have dealt effectively with the of the various vehicle classes (e.g., buses, utility, line haul, diversity and complexity of the vehicle industry for cur- pickup, and delivery). rent laws on fuel consumption and emissions for light-duty vehicles. Engine-based certification procedures have been Recommendation 2-1. Any regulation of medium- and applied to address emissions from heavy-duty vehicles and heavy-duty vehicle fuel consumption should use LSFC as the the myriad of nontransportation engines.

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 SUMMARY Finding 3-2. The heavy-duty-truck fuel consumption regu- unless driven by regulation or by higher fuel prices. Power- lations in Japan, and those under consideration and study by train technologies (for diesel engines, gasoline engines, the European Commission, provide valuable input and expe- transmissions, and hybrids) as well as vehicle technologies rience to the U.S. plans. In Japan the complexity of MHDV (for aerodynamics, rolling resistance, mass/weight reduc- configurations and duty cycles was determined to lend itself tion, idle reduction, and intelligent vehicles) are analyzed in to the use of computer simulation as a cost-effectives means Chapters 4 and 5. Tables S-1 and S-2 provide the committee’s to calculate fuel efficiency, and Japan is not using extensive estimate of the range of fuel consumption reduction that is full-vehicle testing in the certification process. potentially achievable with new technologies in the period 2015 to 2020, compared to a 2008 baseline.1 Figure S-1 provides estimates for potential fuel consumption reductions TECHNOLOGIES AND COSTS OF REDUCING FUEL for typical new vehicles in the 2015 to 2020 time frame. CONSUMPTION The technologies were grouped into time periods based The committee has evaluated a wide range of fuel-saving on the committee’s estimate of when the technologies would technologies for medium- and heavy-duty vehicles. Some be proven and available. In practice, the timing of their in- technologies, such as certain aerodynamic features, automat- troduction will vary by manufacturer, based in large part on ed manual transmissions, and wide-base single low-rolling- individual company product development cycles. In order resistance tires, are already available in production. Some to manage product development costs, manufacturers must of the technologies are in varying stages of development, consider the overall product life cycle and the timing of new while others have only been studied using simulation models. product introductions. As a result, widespread availability Reliable, peer-reviewed data on fuel-saving performance is of some technologies may not occur in the time frames available only for a few technologies in a few applications. shown. As a result, the committee had to rely on information from a The percent fuel consumption reduction (% FCR) num- wide range of sources, (e.g., information gathered from ve- bers shown for individual technologies and other options are hicle manufacturers, component suppliers, research labs, and not additive. For each vehicle class, the % FCR associated major fleets during site visits by the committee), including with combined options is as follows: many results that have not been duplicated by other research- % FCRpackage = 100 [1 – (1 – {% FCRtech1/100}) (1 – ers or verified over a range of duty cycles. T here is a tendency among researchers to evaluate {% FCRtech2/100}) … {(1 – {% FCRtechN/100})] technologies under conditions which are best suited to that specific technology. This can be a serious issue in situations where % FCRtechx is the percent benefit of an individual where performance is strongly dependent on duty cycle, as technology. is the case for many of the technologies evaluated in this re- The major enabling technologies necessary to achieve port. One result is that the reported performance of a specific these reductions are hybridization, advanced diesel engines, technology may be better than what would be achieved by and aerodynamics. Hybridization is particularly important the overall vehicle fleet in actual operation. Another issue in those applications with the stop-and-go duty cycles with technologies that are not fully developed is a tendency characteristic of many MHDVs, such as refuse trucks and to underestimate the problems that could emerge as the transit buses, as well as bucket trucks. Diesel and gasoline technology matures to commercial application. Such issues engine advancements are helpful in all applications and will often result in implementation delays as well as a loss of include continuing improvements to fuel injection systems, performance compared to initial projections. As a result of emissions control, and air handling systems, in addition to these issues, some of the technologies evaluated in this report commercialization of waste heat recovery systems. Essen- may be available later than expected, or at a lower level of tially all Class 8 vehicles will continue with diesel engines performance than expected. Extensive additional research as the prime mover. The third major technology improvement would be needed to quantify these issues, and regulators will is total vehicle aerodynamics, especially in over-the-road need to allow for the fact that some technologies may not applications like tractor trailers and motor coaches. Other mature as expected. technologies that will play a role in reducing fuel consump- The fuel-saving technologies that are already available tion in all vehicle segments include low-rolling-resistance on the market generally result in increased vehicle cost, and tires, improved transmissions, idle-reduction technologies, purchasers must weigh the additional cost against the fuel weight reduction, and driver management and coaching. savings that will accrue. In most cases, market penetration The applications of these technologies can be put into is low at this time. Most fuel-saving technologies that are packages and then applied to the seven types of MHDVs under development will also result in increased vehicle cost, analyzed. The resulting fuel consumption reduction for each and in some cases, the cost increases will be substantial. As a result, many technologies may struggle to achieve market 1 Moreinformation on the baseline can be found in Chapter 6 and in acceptance, despite the sometimes substantial fuel savings, TIAX (2009).

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 TECHNOLOGIES AND APPROACHES TO REDUCING THE FUEL CONSUMPTION OF MEDIUM- AND HEAVY-DUTY VEHICLES TABLE S-1 Range of Fuel Consumption Reduction TABLE S-2 Range of Fuel Consumption Reduction Potential, 2015-2020, for Power Train Technologies Potential, 2015-2020, for Vehicle Technologies Technology Fuel Consumption Reduction (%) Technology Fuel Consumption Reduction (%) Diesel engines 15 to 21 Aerodynamics 3 to 15 Gasoline engines Up to 24 Auxiliary loads 1 to 2.5 Diesel over gasoline engines 6 to 24 Rolling resistance 4.5 to 9 Improved transmissions 4 to 8 Mass (weight) reduction 2 to 5 Hybrid power trains 5 to 50 Idle reduction 5 to 9 Intelligent vehicle 8 to 15 NOTE: Potential fuel reductions are not additive. For each vehicle class, the fuel consumption benefit of the combined technology packages is cal - NOTE: Potential fuel reductions are not additive. For each vehicle class, culated as follows: [% FCRpackage = 100 [1 – (1 – {% FCRtech1 /100}) (1 – the fuel consumption benefit of the combined technology packages is cal - culated as follows: [% FCRpackage = 100 [1 – (1 – {% FCRtech1/100 }) (1 – {% FCRtech2/100)} … (1 – {% FCRtechN /100})]. Values shown are for one set of input assumptions. Results will vary depending on these assumptions. {% FCR tech2/100)} … (1 – {% FCRtechN/100})]. Values shown are for one set of input assumptions. Results will vary depending on these assumptions. SOURCE: Adapted from TIAX (2009). vehicle type will be dependent on the typical vehicle applica- The first measure, dollars per percent fuel saved, is the cost tion and the typical duty cycle. The results of the packages on of the technology package divided by the percent reduction fuel consumption reduction from a 2008 baseline are shown in fuel consumption. The second measure, dollars per gallon for the 2015 to 2020 time frame in Figure S-1. saved per year, accounts for the fact that some vehicles are The technology packages that result in the fuel consump- normally driven more miles than others. The measure calcu- tion reduction for each application also have projected costs. lates how much it costs to save one gallon of fuel each year The costs are estimated assuming the technologies will be for the life of the vehicle by adopting the relevant technol- produced at large enough volumes to achieve economies of ogy. The third measure, “breakeven” fuel price, represents scale in the 2015 to 2020 time frame. The committee has also the fuel price that would make the present discounted value determined several ways to measure costs versus benefits. FIGURE S-1 Comparison of 2015-2020 new-vehicle potential fuel-saving technologies for seven vehicle types: tractor trailer (TT), Class 3-6 Figure S-1 Comparison of 2015-2020...and Class 2b pickups.eps box (box), Class 3-6 bucket (bucket), Class 8 refuse (refuse), transit bus (bus), motor coach (coach), and Class 2b pickups and vans (2b). bitmap NOTE: TIAX (2009) only evaluated the potential benefits of driver management and coaching for the tractor-trailer class of vehicles. It is clear to the committee that other vehicle classes would also benefit from driver management and coaching, but studies showing the benefits for specific vehicle classes are not available. For more information, see the subsection “Driver Training and Behavior” in Chapter 7. Also, potential fuel reductions are not additive. For each vehicle class, the fuel consumption benefit of the combined technology packages is cal - culated as follows: [% FCRpackage = 100 [1 – (1 – {% FCRtech1/100}) (1 – {% FCRtech2/100)} … (1 – {% FCRtechN/100})]. Values shown are for one set of input assumptions. Results will vary depending on these assumptions. SOURCE: TIAX (2009).

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 SUMMARY Major Findings and Recommendations— of the fuel savings equal to the total costs of the technology Chapters 4, 5, and 6: Technologies and Direct Impacts package applied to the vehicle class. The breakeven fuel price shown in Table S-3 does not Finding 4/5/6-1. The fuel consumption reduction potential necessarily reflect how vehicle buyers would evaluate tech- of specific power train and vehicle technologies is extremely nologies, because they often do not plan to own a vehicle for dependent on application (pickup vs. tractor trailer) and duty its full life, they may use a different discount rate, and they cycle (start-stop vs. steady state, variations in load, etc.). would need to consider operation and maintenance costs, which are excluded from the calculation. However, a life- Finding 4/5/6-2. Technologies vary significantly in the time breakeven price is a useful metric for considering both cost-benefit evaluation. Some technologies are economi- the private and the societal costs and benefits of regulation. cally viable at today’s fuel prices. Others examined require Although incomplete, the measures shown in Table S-3 are significantly higher fuel prices or correspondingly high valu- suggestive of the differences in economic viability of the ations of environmental and security externalities to justify various technology options for the indicated vehicle classes. their application. It is important to remember, however, that these breakeven prices are calculated assuming that all the technologies are Finding 4/5/6-3. Cost per percent fuel saved is a widely applied as a package. In fact, individual fuel-saving technolo- used metric for evaluating the cost/benefit of fuel-saving gies applied in a given vehicle class may face much lower technologies, and this metric is also used here. Unfortunately, or much higher breakeven values than the aggregate figures this metric can be very misleading, because it leaves out the listed in Table S-3. For more detailed information on the critical component of total annual vehicle fuel consumption. values summarized in Table S-3, see Tables 6-18 and 6-19 Table S-3 shows great discrepancies between cost per percent in Chapter 6. fuel saved and cost per gallon saved. The findings and recommendations below combine mate- rial from Chapters 4 through 6 and therefore do not match Recommendation 4/5/6-1. The federal government should the numbering in those chapters but are presented instead as continue to support programs in industries, national labora - “Finding 4/5/6-X.” tories, private companies, and universities to develop MHDV technologies for reducing fuel consumption. TABLE S-3 Fuel Consumption Reduction Potential for Typical New Vehicles, 2015-2020, and Cost-Effectiveness INDIRECT EFFECTS AND EXTERNALITIES Comparisons for Seven Vehicle Configurations In addition to the direct costs and benefits associated Cost-Effectiveness Metric with the application of new technologies, there are also in- Dollars Dollars direct costs, benefits, and externalities (impacts that are not Fuel per per Breakeven expressed in market terms) that should be discussed and ad- Consumption Capital Percent Gallon Fuel dressed. Some of these indirect effects represent unintended Pricea Reduction Cost Fuel Saved consequences associated with technologies or policies de- Vehicle Class (%) ($) Saved per Year ($/gal) signed to spur greater fuel efficiency in MHDVs. Although Tractor- 51 84,600 1,670 7.70 1.10 it recognizes that it did not address an exhaustive list of trailer indirect effects, the committee emphasizes the importance Class 6 box 47 43,120 920 29.30 4.20 of assessment of such effects during policy development to truck Class 6 50 49,870 1,010 37.80 5.40 help avoid or mitigate negative unintended consequences. bucket truck Class 2b 45 14,710 330 33.70 4.80 Major Findings and Recommendations— pickup Chapter 6: Indirect Effects and Externalities Refuse truck 38 50,800 1,320 18.90 2.70 Transit bus 48 250,400 5,230 48.00 6.80 Finding 6-9. A number of indirect effects and unintended Motor coach 32 36,350 1,140 11.60 1.70 consequences associated with regulations aimed at reducing NOTE: Numbers in last three columns are rounded. Also, these point es- fuel consumption in the trucking sector can be important. In timates will vary depending on input assumptions. For each vehicle class, particular, regulators should consider the following effects in the fuel consumption benefit of the combined technology packages is cal - the development of any regulatory proposals: rate of replace- culated as follows: [% FCRpackage = 100 [1 – (1 – {% FCRtech1 /100}) (1 – ment of older vehicles (fleet turnover impacts), increased {% FCRtech2/100)} … (1 – {% FCRtechN/100})]. Values shown are for one set ton-miles shipped due to the lower cost of shipping (rebound of input assumptions. Results will vary depending on these assumptions. aCalculated assuming a 7 percent discount rate and a 10-year life, ex - effect), purchasing one class of vehicle rather than another cluding incremental operating and maintenance costs associated with the in response to a regulatory change (vehicle class shifting), technologies. environmental co-benefits and costs, congestion, safety, and SOURCE: Adapted from TIAX (2009). incremental weight impacts.

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 TECHNOLOGIES AND APPROACHES TO REDUCING THE FUEL CONSUMPTION OF MEDIUM- AND HEAVY-DUTY VEHICLES Finding 6-10. Consumer buying in anticipation of new tor and found suggestive evidence that several approaches— regulations (pre-buy) and retention of older vehicles can particularly driver training and longer combination vehicles slow the rate of fleet turnover and the rate at which regulatory (LCVs)—offer potential fuel savings for the trucking sector standards can affect fleet-wide fuel consumption. that rival the savings available from technology adoption for certain vehicle classes and/or types. Any government action Finding 6-11. Elasticity estimates vary over a wide range, taken to reduce fuel consumption in the trucking sector and it is not possible to calculate with a great deal of con- should consider these alternatives. fidence what the magnitude of the “rebound” effect is for Finding 7-2. Fuel taxes offer a transparent and efficient heavy-duty trucks. The rebound effect measures the increase in ton-miles shipped resulting from a reduction in the cost of method for internalizing the potential societal costs of cli - shipping. Estimates of fuel savings from regulatory standards mate change and oil imports (e.g., energy security) and re- will be somewhat misestimated if the “rebound” effect is not ducing fuel consumption in road transport. Fuel taxes operate considered. to make fuel-saving technologies more attractive and provide incentives for saving fuel in operations, while involving Finding 6-12. Standards that differentially affect the capital fewer unintended consequences than standards. and operating costs of individual vehicle classes can cause Recommendation 7-1. Although the committee recognizes purchase of vehicles that are not optimized for particular operating conditions. The complexity of truck use and the the political difficulty associated with increasing fuel taxes, variability of duty cycles increase the probability of these it strongly recommends that Congress consider fuel taxes unintended consequences. as an alternative to mandating fuel efficiency standards for medium- and heavy-duty trucks. Finding 6-16. Some fuel-efficiency-improving technologies Finding 7-5. A cap-and-trade system, such as is being con- will add weight to vehicles and push those vehicles over federal threshold weights, thereby triggering new operational sidered by Congress that would limit total carbon dioxide conditions and affecting, in turn, vehicle purchase decisions. (CO2) emissions by primary energy producers, would have More research is needed to assess the significance of this implications for the trucking sector. Regulators would then potential impact. not need to develop standards for CO2 emissions that apply to specific trucks and trucking operations, avoiding the com- Finding 6-17. Some fuel-efficiency-improving technolo- plexity of different classes and duty cycles of trucks. On the gies will reduce cargo capacity for trucks that are currently other hand, the cap-and-trade system would likely involve “weighed-out” and will therefore force additional trucks onto new administrative burdens for monitoring emissions from the road. More research is needed to assess the significance the primary producers and policing the system. of this potential impact. Finding 7-7. When there are several fuel-saving options Recommendation 6-1. NHTSA, in its study, should do a nd complex truck operating conditions, performance an economic/payback analysis based on fuel usage by ap- standards are likely to be superior to specific technology plication and different fuel price scenarios. Operating and requirements. maintenance costs should be part of any study. Finding 7-8. Increasing vehicle size and weight limits of- fers potentially significant fuel savings for the entire tractor- ALTERNATIVE APPROACHES trailer combination truck fleet. This approach would need to There may be more effective, less costly, and comple- be weighed against increased costs of road repair. Example mentary approaches than vehicle fuel efficiency standards case studies explored in this report demonstrate fuel savings for reducing fuel consumption of MHDVs, such as training of up to 15 percent or more. These savings are similar in size truck drivers on best practices, adjusting size and weight re- but independent and accumulative of other actions that may strictions on trucks, implementing market-based instruments be taken to improve fuel consumption of vehicles; therefore (e.g., fuel taxes), providing incentives for mode shifting, the net potential benefit is substantial. To achieve these sav- or developing intelligent vehicle and highway systems. As ings would require the federal government to: DOT/NHTSA conduct regulatory analyses of fuel efficiency options, indirect costs and alternative approaches will have • Change regulatory limits that currently restrict vehicle to be identified. weight to 80,000 lb and that freeze LCV operations on the Federal Interstate System. • Establish a regulatory structure that assures safety and Major Findings and Recommendations—Chapter 7 compatibility with the infrastructure. One possible Finding 7-1. The committee examined a number of ap- regulatory structure has been proposed by the Trans- proaches for reducing fuel consumption in the trucking sec- portation Research Board in Regulation of Weights,

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 SUMMARY At the same time, there are commonly acknowledged Lengths, and Widths of Commercial Motor Vehicles, characteristics in the commercial truck and buses market- Special Report 267 (TRB, 2002). place that may be improved by a regulatory approach, such as • Consider the necessary changes that would be re - split incentives between owners and operators (e.g., trailers) quired to permit reasonable access of LCVs to vehicle and the short payback period of 18 months to 2 years, that breakdown yards and major shipping facilities in close create barriers to the adoption of efficiency technologies for proximity to the interstate. many purchasers, suggesting that a well-designed regulatory Recommendation 7-2. Congress should give serious con- program may yield important benefits. Due to the complexity of the vehicle market, the commit- sideration to liberalizing weight and size restrictions and tee was not able to give adequate consideration to the non- should consider how the potential fuel savings and other commercial markets such as personal pickup trucks, school benefits of such liberalization can be realized in a way that buses, and personal motor homes. NHTSA should consider maintains safety and minimizes the cost of potential infra- these applications in its regulatory proposal. structure changes. A fundamental concern raised by the committee and Finding 7-10. Intelligent transportation systems enable those who testified during its public sessions was the tension between the need to set a uniform test cycle for regulatory more efficient use of the existing roadway system by improv- purposes and existing industry practices of seeking to mini- ing traffic flow and reducing or avoiding congestion. mize fuel consumption of medium- and heavy-duty vehicles Finding 7-12. There are significant opportunities for sav- designed for specific routes that may include grades, loads, work tasks, or speeds inconsistent with the regulatory test ings in fuel, equipment, maintenance, and labor when driv- cycle. This concern emphasizes the critical importance of ers are trained properly. Indications are that this could be achieving fidelity between certification values and real-world one of the most cost-effective and best ways to reduce fuel results, in order to avoid driving decisions that hurt rather consumption and improve the productivity of the trucking than help real-world fuel consumption. sector. For example, cases evaluated herein demonstrate Because regulations can lead to unintended consequences, potential fuel savings of ~2 to 17 percent with appropriately either because the variability of tasks within a vehicle class trained drivers. is not adequately dealt with or because regulations may lead Recommendation 7-3. The federal government should to distortions between classes in the costs of accomplishing similar tasks, the committee urges NHTSA to carefully con- encourage and incentivize the dissemination of information sider all factors when developing its regulatory proposal. related to the relationship between driving behavior and fuel savings. For example, one step in this direction could be to establish a curriculum and process for certifying fuel-saving Major Finding and Recommendations—Chapter 8 driving techniques as part of commercial driver license Finding 8-1. While it may seem expedient to focus initially certification and to regularly evaluate the effects of such a on those classes of vehicles with the largest fuel consump- curriculum. tion (i.e., Class 8, Class 6, and Class 2b, which together account for approximately 90 percent of fuel consumption APPROACHES TO FUEL CONSUMPTION REDUCTION of MHDVs), the committee believes that selectively regulat- AND REGULATIONS ing only certain vehicle classes would lead to very serious unintended consequences and would compromise the intent This is an important juncture for the nation. The choices of the regulation. Within vehicle classes, there may be certain that will be made over the course of the next few years will subclasses of vehicles (e.g., fire trucks) that could be exempt establish the regulatory design for MHDV fuel consumption from the regulation without creating market distortions. standards for the next several decades at least. While the strin- gency of the standards themselves may be revisited from time Finding 8-2. L arge original equipment manufacturers to time, the regulatory design elements (regulated parties, cer- (OEMs), which have significant engineering capability, de- tification tests and procedures, compliance methods)—once sign and manufacture almost all Class 2b, 3, and 8b vehicles. established—are far more difficult to modify. Small companies with limited engineering resources make In many cases, the commercial vehicle market is sophis- a significant percentage of vehicles in Classes 4 through 8a, ticated, driven by knowledgeable purchasers who focus on although in many cases they buy the complete chassis from the efficiency of their operations, including the fuel costs larger OEMs. Regulators will need to take the limitations of associated with accomplishing their tasks. Thus, one of the these smaller companies into account. most important challenges facing NHTSA is how to enhance and improve upon the commercial trucking industry’s exist- Finding 8-3. Commercial trailers are produced by a separate ing desire to maximize the fuel economy of its trucks and group of manufacturers that are not associated with truck fleets.

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 TECHNOLOGIES AND APPROACHES TO REDUCING THE FUEL CONSUMPTION OF MEDIUM- AND HEAVY-DUTY VEHICLES manufacturers. Trailers, which present an important op - power train tests, which could lower the cost and adminis- portunity for fuel consumption reduction, can benefit from trative burden yet achieve the needed accuracy of results. improvements in aerodynamics and tires. This is similar to the approach taken in Japan, but with the important clarification that the program would represent all Recommendation 8-1. When NHTSA regulates, it should of the parameters of the vehicle (power train, aerodynamics, regulate the final-stage vehicle manufacturers since they have and tires) and relate fuel consumption to the vehicle task. the greatest control over the design of the vehicle and its Finding 8-13. There is an immediate need to take the major subsystems that affect fuel consumption. Component manufacturers will have to provide consistent component findings and recommendations in this report and begin the performance data. As the components are generally tested at development of a regulatory approach. Significant engineer- this time, there is a need for a standardized test protocol and ing work is needed to produce an approach that results in safeguards for the confidentiality of the data and information. fuel efficiency standards that are cost-effective and that ac- It may be necessary for the vehicle manufacturers to provide curately represent the effects of fuel-consumption-reducing the same level of data to the tier suppliers of the engines, technologies. The regulations should fit into the engineering transmissions, and after-treatment and hybrid systems. and development cycle of the industry and provide meaning- ful data to vehicle purchasers. Recommendation 8-3. NHTSA should establish fuel con- Recommendation 8-5. Congress should appropriate money sumption metrics tied to the task associated with a particular type of MHDV and set targets based on potential improve- for and NHTSA should implement as soon as possible a ments in vehicle efficiency and vehicle or trailer changes to major engineering contract that would analyze several ac- increase cargo-carrying capacity. NHTSA should determine tual vehicles covering several applications and develop an whether a system of standards for full but lightly loaded approach to component testing and related data collection (cubed-out) vehicles can be developed using only the LSFC in conjunction with vehicle simulation modeling to arrive at metric or whether these vehicles need a different metric to LSFC data for these vehicles. The actual vehicles should also properly measure fuel efficiency without compromising the be tested by appropriate full-scale test procedures to confirm design of the vehicles. the actual LSFC values and the reductions measured with fuel consumption reduction technologies in order to validate Finding 8-7. Some certification and compliance methods the evaluation method. seem more practical than others, and the committee ac- Recommendation 8-6. NHTSA should conduct a pilot knowledges that there may be other options or variations that have yet to be identified. Regulating total vehicle fuel program to “test drive” the certification process and validate consumption of MHDVs will be a formidable task due to the the regulatory instrument proof of concept. It should have complexity of the fleet, the various work tasks performed, these elements: and the variations in fuel-consumption-related technologies within given classes, including vehicles of the same model • Gain experience with certification testing, data gath- and manufacturer. ering, compiling, and reporting. There needs to be a concerted effort to determine the accuracy and repeat- Finding 8-9. Using the process and results from existing ability of all the test methods and simulation strategies engine dynamometer testing for criteria emissions to certify that will be used with any proposed regulatory stan- fuel economy standards for MHDVs would build on proven, dards and a willingness to fix issues that are found. accurate, and repeatable methods and put less additional • Gather data on fuel consumption from several repre- administrative burden on the industry. However, to account sentative fleets of vehicles. This should continue to for the fuel consumption benefits of hybrid power trains and provide a real-world check on the effectiveness of the transmission technology, the present engine-only tests for regulatory design on the fuel consumption of trucking emissions certification will need to be augmented with other fleets in various parts of the marketplace and in various power train components added to the engine test cell, either regions of the country. as real hardware or as simulated components. Similarly, the vehicle attributes (aerodynamics, tires, mass) will need to REFERENCES be accounted for, one approach being to use vehicle-specific DOE, EIA. 2009. Annual Energy Outlook 2010 (Preliminary). Washington, prescribed loads (via models) in the test cycle. This will D.C., December. require close cooperation among component manufacturers TIAX, LLC. 2009. Assessment of Fuel Economy Technologies for Medium- and vehicle manufacturers. and Heavy-Duty Vehicles. Final Report. Report to the National Academy of Sciences. Cambridge, Mass. September. Recommendation 8-4. Simulation modeling should be used TRB (Transportation Research Board). 2002. Special Report 267: Regula - tion of Weights, Lengths, and Widths of Commercial Motor Vehicles. with component test data and additional tested inputs from Washington, D.C.: TRB.