Federal Highway Administration Air Quality Performance Measures
Fiscal Year (FY) 2004
FHWA Natural and Human Environment Goal: To protect and enhance the natural environment and communities affected by highway transportation.
In support of this goal, FHWA is committed to enhancing the community and social benefits of highway transportation, and improving the quality of the natural environment by reducing highway-related pollution and by protecting and enhancing ecosystems. Two air quality indicators currently measure our performance in meeting this strategic goal and objective:
- Reducing on-road mobile source emission by 20 percent in 10 years.
- Improving each year the percentage of nonattainment and maintenance areas that are meeting their mobile source emissions budgets.
1. On-Road Mobile Source Emissions
Background
The EPA tracks trend associated with the criteria pollutants, and provides national emissions estimates by pollutant and source1. FHWA uses this data to supply the performance indicators required to measure the reduction of on-road mobile source emissions. One limitation in using this report is that there is generally a 2-year time lag for the emission data. Therefore, data for fiscal year 2003 is still preliminary and data for fiscal year 2004 is not available at this time.
Results for FY 2002 and 2003
In 2002, on-road transportation sources accounted for 55 percent of carbon monoxide (CO) emissions, 35 percent of nitrogen oxides (NOx) emissions, 27 percent of volatile organic compounds (VOC) emissions, and 1 percent of particulate matter (PM-10) emissions2. To establish the trend of on-road mobile source emissions, the annual emissions level is developed by taking the sum of estimated total annual tonnage of on-road mobile source emissions of CO, NOx, VOC, and PM-10.
In order to develop the trend of on-road mobile source emissions, 1996 was selected as the baseline since it was the year with the most recently available data when the FHWA Strategic Plan was developed in 1998. The 1996 baseline is 93.8 million short tons of on-road mobile source emissions. To achieve the goal as set forth in the Strategic Plan, a 2 percent reduction target was established for each year starting in 1998.
The sum total reduction of on-road mobile source emissions from the 1996 levels to 2002 is 20.86 percent. These reductions exceed the target. Preliminary estimates for 2003 note an additional 3.70 percent reduction from the base. Exhibits 1 and 2 illustrate the on-road mobile source emissions data from 1993-2003.
| Year | Emissions in Thousand Short Tons | Total (in Thousand Short Tons) | |||||
|---|---|---|---|---|---|---|---|
| CO | NOx | VOC | PM10 | Emission | Difference from Base Year | Change from Base Year | |
| 1993 | 94,431 | 9,162 | 7,804 | 337 | 111,734 | ||
| 1994 | 89,156 | 9,019 | 7,277 | 321 | 105,773 | ||
| 1995 | 83,881 | 8,876 | 6,749 | 304 | 99,810 | ||
| 1996 | 78,606 | 8,733 | 6,221 | 287 | 93,847 | Base Year* | |
| 1997 | 75,849 | 8,792 | 5,985 | 274 | 90,900 | -2,946 | -3.14% |
| 1998 | 73,244 | 8,619 | 5,859 | 256 | 87,979 | -5,867 | -6.25% |
| 1999 | 68,708 | 8,371 | 5,681 | 241 | 83,001 | -10,846 | -11.56% |
| 2000 | 68,061 | 8,394 | 5,325 | 230 | 82,010 | -11,837 | -12.61% |
| 2001 | 63,476 | 7,774 | 4,952 | 212 | 76,415 | -17,432 | -18.57% |
| 2002 | 62,161 | 7,365 | 4,543 | 204 | 74,273 | -19,574 | -20.86% |
| 2003+ | 58,807 | 7,381 | 4,428 | 187 | 70,802 | -23,044 | -24.56% |
*1996 was selected as the baseline year to measure performance of the Strategic Plan.
+ 2003 estimates are preliminary
EPA revised the emissions methodology used in calculating these estimates.
The adjustments have led to changes in previously reported emissions estimates.
Estimates used in this report reflect the current EPA methodology.
Source: See EPA Air Trends website, available at: http://www.epa.gov/airtrends/.
Exhibit 2: On-Road Mobile Source Emissions (1993-2003*)
2. Percent of Nonattainment and Maintenance Areas Meeting Mobile Source Emissions Budgets
Background
The second air quality indicator is a measure of the number of nonattainment and maintenance areas (including both urban and rural areas) which meet their on-road mobile source emissions budgets to the number of areas with adequate or approved on-road mobile source emissions budgets in their State Implementation Plans. Designated areas without established on-road mobile source emissions budgets are not included in this report. An area may be designated for more than one criteria pollutant; in such areas, each budget is counted in the total. In calculating the percentages, the denominator is the number of nonattainment and maintenance areas that have emissions budgets. The numerator is the number of nonattainment and maintenance areas that are meeting their mobile source emissions budgets. In essence, the numerator is the number of areas with budgets that have demonstrated conformity. The ratio for the current year is then compared with previous years to determine if there has been improvement.
The FHWA division offices annually collect the data for this indicator at a snapshot in time each year, and by area and pollutant. July 1 has been chosen as the day of the snapshot each year. Nonattainment and maintenance areas throughout the year may have experienced a change in their conformity status. However, due to the nature of the transportation conformity process, as well as the data collection process and reporting period, this report only represents their status on July 1. Further, the EPA may approve or find adequate budgets throughout the year. The total number of areas with emissions budgets therefore is not constant over the report years.
Results for FY 2004
As is illustrated in Exhibits 3 and 4, a high percentage of nonattainment and maintenance areas demonstrated that they were meeting their emission goals in fiscal year 2004. As of July 1, 2004, 101 out of 105 (96.2 percent) ozone areas, 58 out of 61 (95.1 percent) CO areas, and 38 out of 39 (97.4 percent) PM-10 areas designated as nonattainment or maintenance had met their on-road mobile source emissions budgets. Although this year a slightly lower percentage of ozone areas met their on-road mobile source emissions budgets, the percentage of nonattainment and maintenance areas meeting their emissions budgets remain high. An analysis of the MPOs in a conformity lapse reveals that three of the MPOs were unable to meet their emissions budgets. The other two MPOs were in a conformity lapse for a failure to meet the plan update deadline. It is important to note however that in each of these areas, FHWA worked closely with State and local officials and other Federal partners to re-establish conformity to minimize projects delays.
| Fiscal Year (as of July 1) | Percent of Nonattainment & Maintenance Areas Meeting Emission Goals | ||
|---|---|---|---|
| Ozone | CO | PM10 | |
| 1996 | 96.7 | 92.6 | 68.2 |
| 1997 | 98.0 | 96.2 | 86.4 |
| 1998 | 90.3 | 96.4 | 96.0 |
| 1999* | 93.0 | 96.2 | 100 |
| 2000 | 97.8 | 95.7 | 100 |
| 2001 | 97.0 | 100 | 94.4 |
| 2002 | 98.0 | 100 | 96.3 |
| 2003 | 96.7 | 92.4 | 93.5 |
| 2004 | 96.2 | 95.1 | 97.4 |
*Data is incomplete for 1999; only 40 States provided information.
Exhibit 4: Areas Meeting On-Road Mobile Source Emission Goal (FY 1996-2004)
*Data is incomplete for 1999; only 40 States provided information.
Summary
The indicators demonstrate that the on-road mobile source emissions are on track for achieving a 20 percent reduction over the strategic 10-year period (1998-2007). The percentage of nonattainment and maintenance areas meeting their mobile source emissions budget have varied over time due to the "snapshot" nature of the measurement; however, the overall trend and level is generally favorable.
1EPA National Emissions Inventory, Average Annual Emissions: All Criteria Pollutants, Years Included 1980, 1985, 1989-2000. Available: http://www.epa.gov/ttn/chief/trends/trends00/trends2000.pdf.
21 percent of PM-10 emissions does not include fugitive dust.
