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Improve Vehicles and Fuels

Various programs and initiatives are seeking ways to improve fuel efficiency and reduce emissions from existing vehicles, and to incorporate new technologies in vehicle development. Techniques for improving vehicle performance include the following:

  • Alternative fuels – Many fuels or power sources derived from resources other than petroleum produce less pollution than gasoline or diesel. These include as ethanol, biodiesel, natural gas, propane, hydrogen, and electricity. The U.S. Department of Energy notes that use of alternative fuels and advanced vehicles helps to reduce vehicle emissions.
  • Advanced technology vehicle – This is a vehicle that combines new engine, power, or drivetrain systems to improve fuel economy and meet specific emissions standards under the Clean Air Act. These include vehicles that use hybrid power systems and fuel cells, and some specialized electric vehicles.
  • Ecodriving – This is a method of driving that improves fuel economy and reduces vehicle emissions. It includes maintaining a steady speed, shifting earlier to a higher gear, and keeping tires properly inflated. Various agencies and organizations promote ecodriving as a strategy with potential environmental and safety benefits.
  • Crash avoidance features – Technologies have become available to help drivers avoid collisions. These include forward collision warning, autobrake, lane departure warning, lane departure prevention, adaptive headlights, blind spot detection, parking sensors, back-up cameras, and electronic stability control.
  • Diesel bus retrofitting – Emissions from older, diesel buses can be diminished by installing devices in the exhaust system to reduce specific pollutants. Examples of retrofit devices include diesel particulate filters, diesel oxidation catalysts, selective catalytic reduction systems, and exhaust gas recirculation. Retrofits are incorporated in the U.S. EPA’s National Clean Diesel Campaign.
  • Vehicle inspection and maintenance programs – These programs help improve air quality by identifying high-emitting vehicles in need of repair (through visual inspection, emissions testing, or downloading of fault codes from a vehicle's onboard computer) and requiring them to be fixed as a prerequisite to vehicle registration. More than half of states have some sort of vehicle inspection and maintenance program in place.

Such strategies can promote health through improvements to air quality. Some might also contribute to improved safety outcomes.

Related Transportation and Heath Tool Indicators

How can this strategy result in health benefits?

  • Improve safety
  • Reduce motor vehicle-related injuries and fatalities
  • Reduce transportation's contribution to air pollution

How has this worked in practice?

The Magic School Bus Gets Cleaned Up

The U.S. EPA, in collaboration with Scholastic, created a new book in the "Magic School Bus" series for children. In "The Magic School Bus Gets Cleaned Up," students and their teacher research the pollution emitted from their diesel school bus and learn how emissions from the diesel engine can be reduced. At the end of the book, a diesel particulate matter filter is installed on the bus. U.S. EPA has also translated the book into Spanish. Scholastic operates a traveling science laboratory housed in a yellow school bus that tours the United States, visiting schools, fairs, and community events. As a part of the program, the traveling bus was retrofitted with a diesel particulate filter, reducing particulate matter by up to 90%.

Where can I learn more?

The U.S. Department of Energy Alternative Fuels Data Center provides information, data, and tools to help vehicle fleets and transportation decision makers find ways to reduce petroleum consumption through the use of alternative and renewable fuels, advanced vehicles, and other fuel-saving measures.

The U.S. DOT provides resources and information on fuel economy and air quality impacts.

The U.S. EPA Office of Transportation and Air Quality site has information about controlling emissions from passenger cars and light trucks, and from heavy-duty trucks, buses, and engines. This includes consumer information, vehicle standards and regulations, certification and compliance, inspection and maintenance, fuel economy, and test data and evaluations.

Evidence base

Barone TL, Storey JME, Domingo N. An analysis of field-aged diesel particulate filter performance: Particle emissions before, during, and after regeneration. Journal of the Air & Waste Management Association (JA&WMA) 2010;60(8):968-76.

Beatty T, Shimshack JP. School buses, diesel emissions, and respiratory health. Journal of Health Economics 2011;30(5):987-99.

Borak J, Srianni G. Studies of self-pollution in diesel school buses: Methodological issues. Journal of Occupational and Environmental Hygiene 2007;4(9):660-8.

Boriboonsomsin K, Vu A, Barth M. Eco-Driving: Pilot Evaluation of Driving Behavior Changes among U.S. Drivers. University of California Riverside, University of California Transportation Center (UCTC); 2010.

Dehart-Davis L, Corley E, Rodgers MO. Evaluating vehicle inspection/maintenance programs using on-road emissions data: The Atlanta reference method. Evaluation Review 2002;26(2):111-46.

Eisinger DS. Evaluating inspection and maintenance programs: A policy-making framework. Journal of the Air & Waste Management Association 2005;55(2):147–62.

Haller M, Welch E, Lin J, Fulla S. Economic costs and environmental impacts of alternative fuel vehicle fleets in local government: An interim assessment of voluntary ten-year fleet conversion plan. Transportation Research Part D: Transport and Environment 2007;12(3):219-230.

Hill J, Nelson E, Tilman D, Polasky S, Tiffany D. Environmental, economic, and energetic costs and benefits of biodiesel and ethanol benefits. Proceedings of the National Academy of Science 2006;103(30):11206-10.

Jermakian J. Crash avoidance potential of four passenger vehicle technologies. Accident Analysis and Prevention 2011;43(3):732-740.

Kidd D, Brethwaite A. Visibility of children behind 2010-2013 model year passenger vehicles using glances, mirrors, and backup cameras and parking sensors. Accident Analysis and Prevention 2014;66:158-167.

Legal Information Institute, U.S. Code, Title 42, Chapter 152, Subchapter I, § 17013. Advanced technology vehicles manufacturing incentive program. Retrieved on July 2, 2014.

Leiby P, Rubin J. Understanding the transition to new fuels and vehicles: Lessons learned from analysis and experience of alternative fuel and hybrid vehicles. Saint Louis, MO: Elsevier Academic Press; 2004.

Trenbath K, Hannigan MP, Milford JB. Evaluation of retrofit crankcase ventilation controls and diesel oxidation catalysts for reducing air pollution in school buses. Atmospheric Environment 2009;43(37):5916-22.

U.S. Environmental Protection Agency (EPA). Devices and Additives to Improve Fuel Economy and Reduce Pollution – Do They Really Work?. Washington, DC: U.S. EPA, Office of Transportation and Air Quality; EPA-420-F-11-036; 2011.

U.S. Environmental Protection Agency (EPA). Diesel retrofit technology: An analysis of the cost-effectiveness of reducing particulate matter emissions from heavy-duty diesel engines through retrofits. Washington, DC: U.S. EPA, Office of Transportation and Air Quality; 2006.

Wang MQ. Fuel-cycle greenhouse gas emissions impacts of alternative transportation fuels and advanced vehicle technologies. Transportation Research Record 1999;1664:9-17.

Zhang Q, Zhu Y. Performance of school bus retrofit systems: Ultrafine particles and other vehicular pollutants. Environmental Science & Technology 2011;45(15):6475-82.