For in-depth information, check out our Transportation Backgrounder.
Transportation moves people, goods, and fuel from one place to another. Unfortunately, the vehicles and equipment used to move all that can pollute the air and harm human health. Hard work over the past decades has helped cut these emissions.
Many kinds of transportation exist
- Highway vehicles. Cars, SUVs, trucks travel trillions of miles in the U.S. each year. 1
- Public Transit. From bus services to commuter rail, many transit services use more than one mode.
- Aircraft. These range from U.S. and international major carriers to the general aviation fleet that includes small passenger planes and agricultural aircraft.
- Marine. Barges, ferries, tugs, fishing vessels and workboats operate to, from, and between U.S. ports.
- Rail. Large rail companies transport freight across the U.S.
- Pipelines. More than 500,000 miles of pipelines carry crude oil, natural gas and petroleum products from the wellhead to the refinery and to markets.
Transportation affects the air we breathe
- Tailpipe emissions are the source of significant air pollutants. Burning gasoline and diesel fuel contributes particulate matter (PM), nitrogen oxides (NOx) and volatile organic compounds (VOCs), as well as carbon dioxide (CO2), into the air. While not transportation vehicles, heavy equipment like tractors and bulldozers have similar tailpipe emissions.
- Ocean-going marine vessels are also a major source of sulfur dioxide, nitrogen dioxide and particle pollution emissions. There are much higher concentrations of sulfur in their fuel than domestic diesel.
- Aircraft emissions cross the nation, and include nitrogen dioxide, carbon monoxide, sulfur dioxide, volatile organic compounds, particle pollution, and hazardous air pollutants 2. Lead is not used in jet airplanes, but it is still used in smaller piston-engine powered aircraft.
Transportation emissions affect some communities more than others.
- Areas near high-traffic roadways often have much higher levels of pollution than the rest of the community. An estimated 30 to 45 percent of the people in North American cities live or work near enough to a busy road to experience significantly higher levels of pollution.3
- Areas near airports serving smaller aircraft can have high levels of lead. Lead is still used in fuel for smaller aircraft, which are generally used for instructional flying, air taxi activities, agricultural use and personal transportation.
- Port communities have emissions from ships and barges, but they also have trucks, trains and heavy equipment used to transfer goods to and from the ships. International shipping brings vessels with higher emissions into port. Beginning in 2012, the international agreement has required these large ships to reduce their emissions once they reach 200 nautical miles from the U.S. coastline.
- Poor and disadvantaged communities often bear a disproportionate burden of transportation emissions because many major transportation facilities (major highways, rail yards, freight depots, and ports) are located in and near their neighborhoods.
- U.S. Department of Energy (DOE 2015). Transportation Energy Data Book: Edition 34, September 2015. http://cta.ornl.gov/data/index.shtml
- Federal Aviation Administration Office of Environment and Energy (FAA 2005). Aviation & Emissions: A Primer, January 2005. http://www.faa.gov/regulations_policies/policy_guidance/envir_policy/media/AEPRIMER.pdf
- Health Effects Institute (HEI 2010). Traffic-Related Air Pollution: A Critical Review of the Literature on Emissions, Exposure, and Health Effects, January 17, 2010. http://pubs.healtheffects.org/view.php?id=334