Table 5-12. Nitrogen Oxides and Particulate Matter Emissions by Freight Transportation Mode: 2002

Trucks are by far the largest contributor to freight emissions nationally, producing two-thirds of NOx and PM-10 from the freight sector. The U.S. Environmental Protection Agency passed new rules requiring the use of ultra low sulfur diesel (ULSD) fuel in heavy-duty trucks and other diesel-powered highway vehicles beginning in June 2006. ULSD will reduce emissions of NOx and PM and enable the use of advanced pollution control technologies to meet 2007 emissions standards.

Table in Excel format

Mode	NOx Emissions Tons	NOx Emissions Percent	NOx Emissions As percent of: All mobile sources	NOx Emissions As percent of: All sources	PM-10 Emissions Tons	PM-10 Emissions Percent	PM-10 Emissions As percent of: All mobile sources	PM-10 Emissions As percent of: All sources
Heavy-duty vehicles	3,782,000	66.8	33.0	17.9	120,000	64.7	23.3	0.5
Freight railroads	857,200	15.1	7.5	4.1	21,300	11.5	4.1	0.1
Marine vessels	1,011,000	17.9	8.8	4.8	44,000	23.7	8.5	0.2
Air freight	8,200	0.1	0.1	0.0	300	0.2	0.1	0.0
Total	5,658,400	100.0	49.4	26.8	185,600	100.0	36.0	0.8

Source: U.S. Department of Transportation, Federal Highway Administration, Impacts of Freight Movement on Air Quality, prepared by ICF Consulting, January 26, 2005, based on U.S. Environmental Protection Agency, National Emissions Inventory.