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Compiled and published by the U.S. Department of Transportation's Bureau of Transportation Statistics (BTS), National Transportation Statistics presents information on the U.S. transportation system, including its physical components, safety record, economic performance, energy...
KEY: kWh = kilowatt hour; R = revised; U = data are not available.
KEY: NA = not applicable; R = revised.
Very large urban areas - 3 million and over population.
Large urban areas - 1 million to less than 3 million population.
Medium urban areas - 500,000 to less than 1 million population.
Small urban areas - less than 500,000 population.
KEY: NA = not applicable; R = revised.
Very large urban areas – 3 million and over population.
Large urban areas – 1 million to less than 3 million population.
Medium urban areas – 500,000 to less than 1 million population.
Small urban areas – less than 500,000 population.
a Rank is based on the calculated point change with the highest number corresponding to a rank of 1.
b Average weighted by vehicle miles traveled in city.
KEY: NA = not applicable; R = revised.
Very large urban areas – 3 million and over population.
Large urban areas – 1 million to less than 3 million population.
Medium urban areas – 500,000 to less than 1 million population.
Small urban areas – less than 500,000 population.
a Rank is based on the calculated percent change with the highest number corresponding to a rank of 1.
b Averages weighted by Vehicle Miles Traveled.
KEY: NA = not applicable; R = revised.
Very large urban areas – 3 million and over population.
Large urban areas – 1 million to less than 3 million population.
Medium urban areas – 500,000 to less than 1 million population.
Small urban areas – less than 500,000 population.
a Percent changes were calculated using the numbers in this table and were not obtained from the source. Rank is based on the calculated percent change with the highest number corresponding to a rank of 1.
KEY: O3 = ozone; Pb = lead; PM-10 = particulate matter smaller than 10 micrometers; PM-2.5 = particulate matter smaller than 2.5 micrometers; SO2 = sulfur dioxide.
a States are listed alphabetically. Some states on a row may be nonattainment for some pollutants and not for others in the general area. A multi-state area with states that have not all been redesignated to maintenance is counted as a nonattainment area until all of the states in the area are redesignated, with the whole area...
KEY: CO = carbon monoxide; g/kW-hr = gram per kilowatt-hour; HC = hydrocarbons; THC = total hydrocarbon; kW = kilowatt; NOx = nitrogen oxides; PM = particulate matter; rpm = revolutions per minute.
a Tier 2 emissions standards established by Congress apply to commercial compression-ignition (diesel) engines with a power rating of at least 37 kW. Both propulsion and auxiliary engines are covered under these standards, but land-based engines used in portable auxiliary equipment must meet standards for land-based engines. Smaller compression-ignition engines are...
KEY: CO = carbon monoxide; g = gram; g/kN = grams of pollutant per kilonewtons of thrust; HC = hydrocarbon, kN = kilonewtons; kW = kilowatt; NOx = nitrogen oxides; rO = rated output, which is the maximum power or thrust available for takeoff; rPR = rated pressure ratio.
a Federal standards apply to all planes operating in the United States, regardless of where they were manufactured. This table primarily displays exhaust emissions standards for newly manufactured aircraft engines. Only two standards (smoke standards) have been set for in-use aircraft...