TABLE 74a Change in Nitrogen Oxide Emissions by Mode: 1991-2001
TABLE 74a Change in Nitrogen Oxide Emissions by Mode: 1991-2001
Index: 1991 = 1.00
Excel | CSV | Graphic Version
| 1991 | 1992 | 1993 | 1994 | 1995 | 1996 | 1997 | 1998 | 1999 | 2000 | 2001 | |
|---|---|---|---|---|---|---|---|---|---|---|---|
| Highway gasoline | 1.00 | 0.96 | 0.91 | 0.87 | 0.83 | 0.78 | 0.77 | 0.74 | 0.71 | 0.69 | 0.72 |
| Highway diesel | 1.00 | 1.03 | 1.07 | 1.11 | 1.14 | 1.18 | 1.21 | 1.22 | 1.19 | 1.24 | 1.16 |
| Aircraft | 1.00 | 1.01 | 1.03 | 1.04 | 1.04 | 1.06 | 1.19 | 1.30 | 1.43 | 1.26 | 1.16 |
| Marine vessels | 1.00 | 1.01 | 1.02 | 1.03 | 1.04 | 1.05 | 1.00 | 0.95 | 0.90 | 1.00 | 1.00 |
| Railroad | 1.00 | 1.02 | 1.04 | 1.05 | 1.07 | 1.09 | 1.10 | 1.12 | 1.13 | 1.04 | 1.04 |
| Other nonroad | 1.00 | 0.97 | 1.03 | 1.03 | 1.03 | 1.10 | 1.19 | 1.11 | 1.37 | 1.19 | 1.19 |
NOTES: Highway gasoline vehicles include: light-duty gas vehicles and motorcycles, light-duty gas trucks, and heavy duty gas vehicles. Highway diesel includes heavy-duty diesel vehicles, light-duty diesel trucks and vehicles. Marine vessels include: coal, diesel, residual oil, gasoline and other. Other includes: diesel and gasoline recreational vehicles, airport service, railway maintenance, and recreational marine service. These tables do not include farm, construction, industrial, logging, light commercial, and lawn and garden equipment.
SOURCE: U.S. Environmental Protection Agency (EPA), Office of Air Quality Planning and Standards, "National Emissions Inventory, Air Pollutant Emission Trends," available at http://www.epa.gov/ttn/chief/trends/index.html/, as of August 2002.