2005 annual air quality report (Georgia Regional Transportation Authority)

Georgia Regional Transportation Authority 2005 Air Quality Report
This report fulfills the statutory requirement for the Georgia Regional Transportation Authority (GRTA) to formulate measurable targets for air quality improvements and standards within the geographic area over which the authority has jurisdiction and to report annually such targets to the Governor [Official Code of Georgia Annotated 50-32-13 (c)].

Table of Contents
Table of Contents......................................................................................................................................... i List of Figures............................................................................................................................................. ii List of Tables ............................................................................................................................................. iii Introduction..................................................................................................................................................1 Air Quality ...................................................................................................................................................1
Ground-Level Ozone ...............................................................................................................................2 1-Hour Ozone Standard .......................................................................................................................4 8-Hour Ozone Standard .......................................................................................................................4
Fine Particulate Matter ............................................................................................................................4 PM2.5 Standards ...................................................................................................................................6 Proposed Changes to the PM2.5 Standards ..........................................................................................6
Mobile Source Air Toxics .......................................................................................................................7 Greenhouse Gas Emissions......................................................................................................................7 Georgia Nonattainment Areas .....................................................................................................................8 Measures and Targets ................................................................................................................................10 Air Quality Measures.............................................................................................................................10
Atlanta 8-Hour Ozone Standard Attainment Status...........................................................................10 Atlanta Ozone Days...........................................................................................................................12 Atlanta Annual PM2.5 Standard Attainment Status ...........................................................................13 Atlanta PM2.5 Days............................................................................................................................15 Emissions Measures...............................................................................................................................16 Atlanta Total Daily Vehicle Emissions .............................................................................................16 Atlanta Average Daily Vehicle Emissions per Person ......................................................................22 Activity Measures..................................................................................................................................23 Atlanta Average Total Daily VMT....................................................................................................23 Atlanta Average Daily VMT per Person ...........................................................................................23 Atlanta Regional Transit Ridership ...................................................................................................25 Atlanta Regional Transit Ridership per Person .................................................................................25 Summary....................................................................................................................................................26 Initiatives ...................................................................................................................................................28 Existing Fuel and Vehicle Initiatives.....................................................................................................28 Potential and/or Future Fuel and Vehicle Initiatives .............................................................................28 Existing Land Use Initiatives.................................................................................................................29 Transportation Initiatives.......................................................................................................................29 Other Existing and Potential Transportation Initiatives ........................................................................31 Appendix....................................................................................................................................................32
i

List of Figures
Figure 1: VOC Emissions in the Atlanta Nonattainment Area .................................................................3 Figure 2: NOx Emissions in the Atlanta Nonattainment Area ..................................................................3 Figure 3: Average Composition of PM2.5 in Atlanta.................................................................................5 Figure 4: Primary PM2.5 Emissions in the Atlanta Nonattainment Area...................................................5 Figure 5: SO2 Emissions in the Atlanta Nonattainment Area ...................................................................6 Figure 6: NH3 Emissions in the Atlanta Nonattainment Area ..................................................................6 Figure 7: CO2 Emissions in Georgia .........................................................................................................7 Figure 8: Georgia Nonattainment Areas ...................................................................................................9 Figure 9: Atlanta 8-Hour Ozone Standard Attainment Status (1995-2005)............................................11 Figure 10: 8-Hour Ozone Standard Attainment Status in Other Georgia Ozone Nonattainment Areas...11 Figure 11: Atlanta Ozone Days Measure (1995-2005) .............................................................................13 Figure 12: Atlanta Annual PM2.5 Standard Attainment Status (2001-2005).............................................14 Figure 13: Annual PM2.5 Standard Attainment Status in Other PM2.5 Nonattainment Areas in Georgia
(2001-2005) .............................................................................................................................14 Figure 14: Atlanta PM2.5 Days (2000-2005) .............................................................................................16 Figure 15: Total Light-Duty and Heavy-Duty Vehicle VOC Emissions in the Atlanta Nonattainment
Area Relative to the Year 2000 ...............................................................................................18 Figure 16: Total Light-Duty and Heavy-Duty Vehicle NOx Emissions in the Atlanta Nonattainment
Area Relative to the Year 2000 ...............................................................................................19 Figure 17: Total Light-Duty and Heavy-Duty Vehicle Primary PM2.5 Emissions in the Atlanta
Nonattainment Area Relative to the Year 2000.......................................................................19 Figure 18: Total Light-Duty and Heavy-Duty Vehicle SO2 Emissions in the Atlanta Nonattainment Area
Relative to the Year 2000 ........................................................................................................20 Figure 19: Total Light-Duty and Heavy-Duty Vehicle NH3 Emissions in the Atlanta Nonattainment
Area Relative to the Year 2000 ...............................................................................................20 Figure 20: Total Light-Duty and Heavy-Duty Vehicle Air Toxics Emissions in the Atlanta
Nonattainment Area Relative to the Year 2000.......................................................................21 Figure 21: Total Light-Duty and Heavy-Duty Vehicle CO2 Emissions in the Atlanta Nonattainment
Area Relative to the Year 2000 ...............................................................................................21 Figure 22: Average Light-Duty Vehicle Emissions per Person in Atlanta Relative to the Year 2000.....22 Figure 23: Atlanta Total Daily VMT (1994-2004) ...................................................................................24 Figure 24: Atlanta Average Daily VMT per Person (1994-2004) ............................................................24 Figure 25: Annual (Unlinked) Transit Trips in the Atlanta Area (1994-2004).........................................25 Figure 26: Annual Unlinked Transit Trips per Person in the Atlanta Area (1994-2004) .........................26
ii

List of Tables
Table 1: Georgia 8-Hour Ozone Nonattainment Areas and Counties ........................................................8 Table 2: Georgia PM2.5 Nonattainment Areas and Counties ......................................................................8 Table 3: AQI Ozone Sub-Index ................................................................................................................12 Table 4: AQI PM2.5 Sub-Index .................................................................................................................15 Table 5: Summary of GRTA Air Quality Measures and Targets .............................................................27 Table 6: Number of Atlanta 8-Hour Average Ozone Readings Above and Below 84 ppb for May
through September 2005.............................................................................................................32
iii

Georgia Regional Transportation Authority 2005 Air Quality Report

activities. The Atlanta region's ongoing efforts

Introduction

to better recognize and act on the linkages

Air quality in Georgia has improved since 2000. The fact that Atlanta attained1 the 1-hour ozone standard in 2004 is evidence of this trend. Factors such as reductions in power plant emissions, the introduction of cleaner vehicles and fuels, the attrition of older, morepolluting vehicles, and favorable weather conditions have contributed to the improvement. For example, between 2000 and 2004, total ozone-producing pollution generated by highways in the 20-county Atlanta nonattainment area dropped approximately 20%. Remarkably, this improvement occurred at the same time that the area added over 500,000 residents,2 which in other circumstances might be expected to increase pollution and worsen air quality. Nevertheless, more work remains to be done to clean up Georgia's air.
Over the past two years, the U.S.

between land use, transportation and air quality, such as transit-oriented developments along MARTA rail lines, the GRTA Developments of Regional Impact policies that encourage development designs that foster trip reductions, and brownfield and infill redevelopments like Atlantic Station, should be encouraged. We must also obtain greater efficiencies from our existing transportation and land use infrastructure.
GRTA will continue to work with the Environmental Protection Division of the Georgia Department of Natural Resources (EPD), the Georgia Department of Transportation (GDOT), the Atlanta Regional Commission (ARC), and other partners towards these goals. This report outlines the air quality issues confronting Georgia, and the measures, targets, and actions that can lead to continued improvement in air quality.

Environmental Protection Agency (EPA) has designated 28 full or partial counties in Georgia

Air Quality

nonattainment under the 8-hour ozone and/or

The air we breathe is composed mostly

annual fine particulate matter standards--

of oxygen and nitrogen, with trace

including counties in the Atlanta, Macon, Rome,

concentrations of countless other naturally

and Chattanooga metropolitan areas. For the

occurring and human-made (or

recent trend towards better air quality to

"anthropogenic") substances. Unfortunately,

continue, the state must implement and

some of the minor constituents, such as carbon

aggressively promote activities that support

monoxide, particulate matter, and ozone, can be

such improvement, where appropriate. Greater

harmful even at very low concentrations.

use of alternative transportation modes such as

Therefore, EPA has set the health-based

carpools, vanpools, and public transit, and increased teleworking are examples of such

National Ambient Air Quality Standards (NAAQS) for six pollutants3 that must be met

throughout the United States. In Georgia, the

1 "Attaining" or "attainment" means that an area is meeting an air quality standard set by the U.S. Environmental Protection Agency. "Nonattainment"

pollutants of most concern are ground-level ozone and fine particulate matter, as described below.

means that an area is not meeting an air quality standard. 2 U.S. Census Bureau,

3 "Ambient" means outdoor air. The six NAAQS

http://www.census.gov/popest/counties/CO-EST2005-

pollutants are carbon monoxide, lead, nitrogen dioxide,

01.html.

ozone, particulate matter, and sulfur dioxide.

1

Ground-Level Ozone
Ozone is a highly reactive, pungent gas composed of three oxygen atoms. In the stratosphere, 10 to 30 miles up, ozone helps protect us from the sun's harmful ultraviolet rays. At ground level, however, ozone can be harmful. Breathing ozone can trigger a variety of health problems including chest pain, coughing, throat irritation, and congestion. It can worsen bronchitis, emphysema, and asthma and can reduce lung function and inflame the linings of the lungs. Repeated exposure may permanently scar lung tissue. A recent study of Atlanta area hospital records found an association between emergency department visits for upper respiratory infections and increases in ambient ozone levels.4 Ground-level ozone can also reduce crop yields, and damage vegetation, ecosystems, and human-made materials such as plastics and paints. It is also a greenhouse gas that may contribute to climate change (see the section entitled "Greenhouse Gas Emissions" below).5,6
Ozone is not emitted directly into the air, but is rather a "secondary" pollutant that forms when other chemicals (or "precursors") combine in the atmosphere under the right conditions. At ground level, ozone is created by a complex series of reactions in the air between nitrogen oxides7 (NOx) and volatile organic compounds8 (VOC) in the presence of heat and sunlight. (Ozone in the stratosphere is formed through a different process.) Ground-level ozone formation is typically greatest during the hot, stagnant weather conditions of summer.

Ozone concentrations vary greatly throughout the course of the day. The morning rush hour is a significant source of NOx and VOC emissions and generally marks the daily onset of ozone formation. As the sun begins to shine, reactions between ozone precursors start up and continue throughout the day. The afternoon rush hour pumps more NOx and VOC into the air, contributing to further ozone formation. Peak concentrations of ozone are typically measured in the afternoon, between 2:00 p.m. and 6:00 p.m. Ozone concentrations drop off significantly in the nighttime due to the lack of sunlight, which shuts down the ozone formation process.9
To assist in air quality planning, EPD compiles inventories of ozone precursors and other emissions from all sources in Georgia. These inventories help identify the relative contributions of the various emissions sources to the state's air quality problems. The sources are categorized into "area," "point," "nonroad mobile," "on-road mobile," and "biogenic" sectors. Examples of area sources are print shops, dry cleaners, restaurants, painting facilities, and outdoor burning. Examples of point sources are power plants and chemical facilities. Examples of nonroad mobile sources are locomotives, aircraft, boats, construction equipment, lawn mowers, chain saws, and leaf blowers. On-road mobile sources include automobiles, trucks, buses, and motorcycles. Examples of biogenic sources are trees, crops, grass, and other vegetation. The most recent emissions inventory was collected for the year 2002, and some key results of that inventory are

discussed below.

4 Peel, J. L.; Tolbert, P. E.; Klein, M.; Metzger, K. B.; Flanders, W. D.; Todd, K.; Mulholland, J. A.; Ryan, P. B.; Frumkin, H.; "Ambient Air Pollution and Respiratory Emergency Department Visits," Epidemiology, 16(2):164-174, March 2005. 5 For general information on ozone, go to www.epa.gov/air/oaqps/gooduphigh/index.html. 6 For extensive information on the formation mechanisms and the health and environmental impacts of ground-level ozone, see EPA's "Air Quality Criteria for Ozone and

In terms of ozone precursors, Figure 1 shows that 42% of VOC emissions in the 20county Atlanta area come from biogenic sources. In fact, biogenic sources emit roughly three-quarters of the VOC statewide. There is typically much more VOC in the air than there is NOx available with which to form ozone. Therefore, ozone production is "NOx limited,"

Related Photochemical Oxidants." 7 NOx is the collective term for nitrogen monoxide (NO)
and nitrogen dioxide (NO2). 8 VOC includes many naturally-occurring and human-

9 USEPA, Office of Air Quality Planning and Standards, "Guideline on Ozone Monitoring Site Selection," EPA-

made carbon-based compounds that evaporate readily.

454/R-98-002, August 1998.

2

and, generally speaking, reducing NOx emissions will reduce ozone levels more effectively than reducing a comparable amount of VOC emissions.10 This has important policy implications since, unlike VOC, NOx emissions are dominated by anthropogenic sources and are therefore easier to control than VOC emissions. Figure 2 shows that anthropogenic sources are responsible for essentially all of the NOx emissions in the 20-county Atlanta nonattainment area, and more than half of those emissions come from on-road mobile sources. Furthermore, more than half of the on-road mobile source NOx emissions are produced by heavy-duty vehicles (i.e., trucks and buses).
Figure 1: VOC Emissions in the 20-County Atlanta Nonattainment Area in 200211

lower than at higher altitudes. The ozone that forms as result of these emissions is closer to the ground, where people are more likely to be exposed to it.
Figure 2: NOx Emissions in the 20-County Atlanta Nonattainment Area in 200212

Nonroad Mobile
15%

Biogenic 0% Area 7%

Power Plants
19%

On-Road Heavy-Duty
Vehicles 33%

Other Point Sources 2%
On-Road Light-Duty Vehicles
24%

Area

Biogenic 42%

31%

Figure 2 indicates that power plants and

on-road and nonroad mobile sources are

significant contributors of ozone precursor

emissions in the Atlanta area. EPD is presently

Point 2%

conducting sensitivity analyses to determine

Nonroad Mobile
6%

On-Road Heavy-Duty
Vehicles

On-Road Light-Duty Vehicles
18%

how important both mobile source and power plant NOx emissions are for reducing ozone concentrations in Atlanta and other areas.

1%
On-road and nonroad mobile sources are significant contributors to ground-level ozone formation in the Atlanta area not only because of the large quantity of precursors they emit, but also because much of their emissions are released in the most heavily-traveled areas in and around the urban core. Mobile sources emit all the chemical ingredients needed to create ozone together near the ground where they are less likely to be transported away from the region since wind speeds at the ground are

Fortunately, on-road mobile source emissions of ozone precursors in Atlanta are expected to decline markedly over the next 1520 years due to replacement of older, more polluting vehicles with newer, cleaner vehicles. Nevertheless, with continued growth it will be important to reduce on-road emissions even more in Atlanta by continuing to encourage the use of alternative modes of transportation, managing travel demand, reducing congestion, and by making more efficient connections between land uses and the transportation

10 EPD estimates that reducing NOx emissions by 1 ton per day in the 20-county Atlanta nonattainment area would be 23 times more effective at lowering ambient ozone concentrations than reducing VOC emissions by 1

system. These additional reductions obtained through changes in travel behavior may be necessary for several reasons: (1) to attain the air quality standards in the short term (i.e., the

ton per day. For more information, see the presentation

next five years); (2) to maintain the standards

by Dr. James Boylan from the 2005 Georgia Air Policy
Symposium. 11 EPA, 2002 National Emissions Inventory. 2002 is the

over the long term after the impact of newer vehicle emissions control technology plateaus;

most recent year for which a comprehensive emissions inventory is available.

12 Ibid.

3

and (3) to reduce public exposure to potentially

standard provides a greater level of protection to

unhealthy levels of motor vehicle pollution in

the public against ozone-related health effects

the vicinity of heavily-congested transportation

than the previous 1-hour ozone standard.

facilities.

Fine Particulate Matter

1-Hour Ozone Standard

Particulate matter is the general term

Until recently, EPA was enforcing two

used for a mixture of solid particles and liquid

forms of the NAAQS for ground-level ozone:

droplets found in the air. Some particles are

the "1-hour" and "8-hour" standards. In

large or dark enough to be seen as soot or

addition to differences in the levels and forms of

smoke. Others are so small they can only be

the two standards, the 1-hour standard was

seen with an electron microscope. These

based on averaging monitored ozone

particles originate from many different sources.

concentrations over 1-hour periods whereas the

Their chemical and physical compositions vary

8-hour standard was based on averaging over

depending on location, time of year, and

consecutive 8-hour periods. The 1-hour standard had been in place for over twenty-five

weather. Fine particulate matter (PM2.5) is less than 2.5 microns (i.e., millionths of a meter) in

years, and for most of that time the Atlanta area

diameter, or about one-fortieth the width of a

did not meet the standard. However, thanks to

human hair, and is so small that it can get deep

reductions in emissions from power plants,

into the lungs and cause serious health

motor vehicles and other sources, as well as favorable weather conditions,13 EPA officially

problems. Numerous scientific studies have linked particle pollution exposure to a variety of

redesignated the Atlanta area to attainment of the 1-hour ozone standard in June 2005.14 Soon

problems, including: increased respiratory symptoms, such as irritation of the airways,

thereafter, EPA revoked the 1-hour ozone

coughing, or difficulty breathing; decreased

standard and from now on will enforce only the 8-hour standard.15 Therefore, the 1-hour ozone

lung function; aggravated asthma; development of chronic bronchitis; irregular heartbeat;

standard will no longer be tracked for purposes

nonfatal heart attacks; and premature death in

of this report.

people with heart or lung disease. Recent

8-Hour Ozone Standard
EPA identified areas that did not meet the new 8-hour ozone standard in June 2004.

studies of Atlanta area hospital records found
associations between emergency department visits for cardiovascular disease17 and pneumonia18 with increases in PM2.5 levels.

EPA set the level of the 8-hour ozone standard at 80 parts per billion (ppb).16 The 8-hour ozone

ppb. Concentrations at or above 85 ppb exceed the standard. The steps in determining whether an area meets

13 Preliminary results of an analysis of ozone trends in

the 8-hour ozone standard are as follows. For each monitor in the area, determine the fourth-highest 8-hour

Atlanta conducted by researchers at EPD indicate that

ozone concentration for the year. Next, take the average

approximately half of the improvement that occurred in

of the fourth-highest 8-hour ozone concentration per year

ozone levels since 1999 is attributable to weather, and

over each of the three most-recent years. Finally, for an

half is due to reductions in ozone precursor emissions.

area to attain the 8-hour ozone standard, this three-year

Marmur, A.; Cohan, D.; Morton, J.; Abrams, D.;

average (also known as the 8-hour ozone "design value")

"Interannual Variability in Ozone Levels in Atlanta:

at each monitor in the area must be less than or equal to

Effect of Emissions, Meteorology, and Ensuring LongTerm Attainment," presented at the 86th American
Meteorological Society Annual Meeting, Atlanta, GA,

84 ppb. For more detail on how to interpret the 8-hour
ozone NAAQS, see 40 CFR 50, Appendix I. 17 Metzger, K. B.; Tolbert, P. E.; Klein, M.; Peel, J. L.;

2006. 14 Atlanta attained the 1-hour ozone standard in 2004,

Flanders, W. D.; Todd, K.; Mulholland, J. A.; Ryan, P. B.; Frumkin, H.; "Ambient Air Pollution and

based on 2002-2004 monitoring data, and was officially

Cardiovascular Emergency Department Visits,"

redesignated in 2005. 70 Federal Register 34660. 15 69 Federal Register 23951. 16 Due to rounding conventions, monitored concentrations

Epidemiology, 15(1):46-56, January 2004. 18 Peel, J. L.; Tolbert, P. E.; Klein, M.; Metzger, K. B.;
Flanders, W. D.; Todd, K.; Mulholland, J. A.; Ryan, P.

of 84 ppb or less are considered to meet the standard of 80

B.; Frumkin, H.; "Ambient Air Pollution and Respiratory

4

Particle pollution can also reduce visibility and damage structures, crops and ecosystems.19,20

Figure 3: Average Composition of PM2.5 in Atlanta23

PM2.5 is a complex mixture of substances and can be both a "primary" (i.e., emitted directly into the air) and a secondary pollutant. Figure 3 below shows the average composition of PM2.5 at a monitor in south DeKalb County. Examples of primary PM2.5 include soot (or "elemental carbon") from diesel engines, organic compounds from incomplete combustion or cooking, compounds containing metals such as arsenic, selenium, and zinc formed during combustion or smelting, and road dust.21 Figure 4 suggests that primary PM2.5 emissions in the Atlanta area are dominated by road dust and other area sources such as windblown soil (or "crustal" material). However, a recent study completed by Georgia Tech concluded that the contribution of area sources to primary PM2.5 emissions in Atlanta is probably overestimated. Instead, the results suggested that diesel and gasoline-powered engines were responsible for almost two-thirds of the primary PM2.5 measured at the particular urban location chosen for the study.22

Other 18% Crustal 2% Elemental Carbon 6%
Nitrate 5%
Ammonium Ion 9%

Organic Carbon
30%
Sulfate 30%

Figure 4: Primary PM2.5 Emissions in the 20-County Atlanta Nonattainment Area in 200224

On-Road
Light-Duty
Vehicles 1% Point 5%

On-Road Heavy-Duty
Vehicles 4%

Nonroad Mobile
4%

Other Area Sources 34%

Roads 52%

Secondary PM2.5 forms in the

atmosphere from chemical precursors such as

VOC, NOx, sulfur dioxide (SO2), and ammonia (NH3). Examples include nitrates formed from NOx and NH3, and sulfates from SO2 and NH3 (the ammonium ion portion of Atlanta PM2.5 levels shown in Figure 3 are generally bound to NOx and SO2 to form these nitrate and sulfate compounds). NOx emissions in Atlanta are dominated by on-road vehicles and coal-fired power plants (Figure 2). Although VOC emissions are dominated by biogenic sources

(Figure 1), currently, there is considerable uncertainty in the scientific community as to the relative importance of biogenic VOC compared to anthropogenic VOC (e.g., from mobile sources) in the production of secondary PM2.5 in urban areas.25 However, the majority of the scientific evidence is indicating that secondary PM2.5 in urban areas is dominated by biogenic VOCs rather than anthropogenic VOCs. Figure 5 on page 6 shows that almost 90% of SO2

emissions in the Atlanta nonattainment area are

Emergency Department Visits," Epidemiology,

attributable to coal-fired power plants. Figure 6

16(2):164-174, March 2005. 19 For general information on particulate matter pollution,
go to www.epa.gov/oar/particlepollution. 20 For extensive information on the formation mechanisms

on page 6 shows that almost half of the NH3 emissions in the Atlanta nonattainment area are released by livestock (e.g., poultry farms).

and the health and environmental impacts of PM2.5, see EPA's "Air Quality Criteria for Particulate Matter." 21 EPA, "Air Quality Criteria for Particulate Matter,"
Volume I, EPA/600/P-99/002aF, October 2004. 22 Amit Marmur, Alper Unal, James A. Mulholland,
Armistead G. Russell, "Optimization-Based Source

23 2004 PM2.5 speciation from South Dekalb site. EPD
2004 Ambient Air Surveillance Report. 24 EPA, 2002 National Emissions Inventory. 25 See, for example, the presentations by Mr. Eric

Apportionment of PM2.5 Incorporating Gas-to-Particle Ratios," Environ. Sci. Technol. 2005, 39, 3245-3254.

Edgerton and Prof. Rodney Weber from the 2005 Georgia Air Policy Symposium.

5

Figure 5: Sulfur Dioxide Emissions in the 20-County Atlanta Nonattainment Area in 200226

planning for PM2.5 in Georgia more effective and efficient.

Other Point Sources 2%

On-Road Mobile 2%

Nonroad Mobile
1%

Area 9%

PM2.5 Standards
There are two forms of PM2.5 NAAQS--

the "24-hour" and "annual" standards--which

are designed to protect against effects from both

short and long-term exposure to fine particulate

matter. Unlike ozone, which is primarily a

summertime pollutant, PM2.5 occurs year-round.

Power Plants
86%

The annual standard is based on measured PM2.5 levels averaged over an entire year. EPA set the level of the annual PM2.5 standard at 15.0

Figure 6: Ammonia Emissions in the 20-County Atlanta Nonattainment Area in 200227

On-Road Light-Duty Vehicles
21%

On-Road Heavy-Duty
Vehicles 1%

micrograms (i.e., millionths of a gram) per cubic meter (g/m3) of air.28 For comparison, a typical grain of salt weighs about 60 g.29 All
areas of Georgia are meeting the 24-hour PM2.5 standard of 65 g/m3. However, several areas
are not meeting the annual standard.

Point 1%

Livestock 49%

Proposed Changes to the PM2.5 Standards

EPA recently proposed changes to the

Other Area

PM2.5 NAAQS, including lowering the 24-hour standard from 65 g/m3 to 35 g/m3.30 EPA

Sources 28%

proposed to keep the level of the annual standard at 15.0 g/m3; however, the final levels

could change based on public comments

It should be noted that the chemistry and physics of PM2.5 formation, especially regarding secondary PM2.5, are not as well understood as for ozone, and there are still important questions to be answered about the sources of, and the best strategies for reducing, PM2.5 in Georgia. For example, in addition to the discrepancies

received by EPA. EPA expects to finalize the changes by September 2006, and the new standards would take effect in 2010. The impact that revised standards would have on Georgia's air quality status will depend on the final form of the standards and on monitoring data at the time the standards are implemented.

between the estimated primary PM2.5 emissions

inventory and actual PM2.5 measurements

mentioned above, on-road and nonroad mobile sources may also play a significant role in causing unhealthy PM2.5 concentrations in localized areas in Georgia, such is in the vicinity

28 The steps in computing the PM2.5 annual average are as follows. First, the 24-hour averages for a calendar year at a given monitoring site are averaged together by quarters (i.e., three month averages). Second, the four quarterly

of heavily-congested transportation facilities (i.e., "hot spots"). GRTA will continue to work with its planning partners to find answers to key questions that will help make air quality

averages are averaged together to calculate the annual average for the year at each monitoring site. Finally, the annual averages for three consecutive years are averaged together to calculate the annual PM2.5 "design value" for comparison with the standard. For more details, see 40

26 EPA, 2002 National Emissions Inventory. 27 Ibid.

CFR 50, Appendix N. 29 See, for example,
www.physlink.com/Education/AskExperts/ae342.cfm. 30 71 Federal Register 2620.

6

Mobile Source Air Toxics
EPA has identified 21 hazardous air pollutants from motor vehicles and motor vehicle fuels known or suspected to cause

environment are uncertain, but potentially very serious.,34
Figure 7: Carbon Dioxide Emissions in Georgia in 199635

cancer or other serious health or environmental

Commercial Production

effects. Collectively, these are referred to as "mobile source air toxics" (MSATs). Among the 21 pollutants, EPA believes diesel particulate matter and diesel exhaust organic

Residential3% 5%
Industrial 10%

Processes 3%
Power Plants
41%

gases, benzene, 1,3-butadiene, formaldehyde,

acetaldehyde, and acrolein are likely to present the highest risks to public health and welfare.31

Although EPA has not set NAAQS for MSATs,

Transpor-

exposure to these pollutants is still a health

tation

38%

concern. GRTA is interested in working in

conjunction with its planning partners to

determine whether Georgians are being exposed to unhealthy levels of MSATs, especially in urban areas and/or in the vicinity of heavilycongested transportation facilities, and, if so, finding ways to reduce the emissions of and/or public exposure to MSATs.

The dominant source of greenhouse gas emissions is fossil fuel combustion, and the primary pollutant is CO2. Figure 7 shows the estimated contribution of CO2 emissions from all sources in Georgia for the year 1996. (1996 is the most recent year for which a Georgia

Greenhouse Gas Emissions
Carbon dioxide (CO2), water vapor,

greenhouse gas inventory is available.) Power plants were the largest contributor to CO2 emissions, followed closely by the

methane, ozone, and a number of other

transportation sector. (The transportation sector

naturally-occurring and human-made

includes both on-road and nonroad sources.)

constituents in the atmosphere help keep the earth much warmer than it would otherwise be.

Nationally, almost 80% of the CO2 emissions from the transportation sector are attributable to

These gases trap heat in a process known as the "greenhouse effect" and are therefore called

gasoline and diesel fuel consumption by automobiles, trucks and buses.36 Although EPA

greenhouses gases. Were it not for the
greenhouse effect, life on earth as we know it would not be possible.32 However, human

has not set a NAAQS for CO2 nor does it regulate CO2 emissions, it is nevertheless important for people to be aware of the impacts

activities such as fossil fuel combustion for

their travel choices and other activities may

electricity generation and transportation are

have on the earth's climate and the environment.

causing a build-up of greenhouse gases in the

atmosphere, leading to increases in surface air
temperatures known as "climate change" or "global warming." 33 The impacts of climate

34 Committee on the Science of Climate Change, Division on Earth and Life Studies, National Research Council, "Climate Change Science: An Analysis of Some Key

change on human health, welfare, and the

Questions," National Academy Press, Washington, D.C.,
2001. 35 "Revised Final Report For Phase I Of The United States

31 66 Federal Register 17230. 32 See, for example,

Environmental Protection Agency's State and Local Climate Change Program: Development Of A Greenhouse Gas Emissions Inventory For The State Of Georgia,"

yosemite.epa.gov/oar/globalwarming.nsf/content/Climate.

Georgia Environmental Protection Division, January,

html. 33 Intergovernmental Panel on Climate Change, "Climate

1999. 36 USEPA, "Inventory Of U.S. Greenhouse Gas

Change 2001: Synthesis Report--Summary for

Emissions and Sinks: 1990 2003," EPA 430-R-05-003,

Policymakers."

March, 2005.

7

GRTA seeks to reduce energy consumption and greenhouse gas emissions in Georgia by reducing traffic congestion and encouraging more energy efficient forms of transportation, such as car- and vanpooling, bus rapid transit, and rail.

Georgia Nonattainment Areas
Table 1 lists the areas and corresponding counties and partial counties in Georgia designated nonattainment under the 8-hour ozone standard, while Table 2 lists the areas and corresponding counties and partial counties designated nonattainment under the annual PM2.5 standard. These areas are also depicted in Figure 8 on page 9.
Table 1: Georgia 8-Hour Ozone Nonattainment Areas and Counties

Area

Counties

result, the area must attain the standard by 2007. The Macon and Murray County ozone nonattainment areas are classified as "basic" and are required to attain the standard by 2009. Catoosa County is part of Chattanooga, Tennessee's "Early Action Compact" with EPA to achieve clean air sooner than would be required under the 8-hour ozone standard regulations. As long as the Chattanooga area continues to fulfill the compact's requirements and meet prescribed milestones, EPA will defer the effective date of its nonattainment designation, including Catoosa County. As an Early Action Compact area, Chattanooga must attain the 8-hour ozone standard by the end of 2007.40 There are no classifications for PM2.5 nonattainment areas, and all PM2.5 areas must attain the standard by 2010.
Table 2: Georgia PM2.5 Nonattainment Areas and Counties

Barrow Carroll Clayton

Bartow Cherokee Cobb

Area

Counties
Barrow Carroll

Bartow Cherokee

Coweta

DeKalb

Clayton

Cobb

Atlanta

Douglas Forsyth Gwinnett

Fayette Fulton Hall

Atlanta

Coweta Douglas Forsyth

DeKalb Fayette Fulton

Henry

Newton

Paulding

Rockdale

Spalding

Walton

Macon Murray

Bibb Murray38

Monroe37

The Atlanta area is classified39 as a "marginal" ozone nonattainment area. As a

Chattanooga Macon

Gwinnett Heard41 Newton Paulding Spalding Catoosa Bibb

Hall Henry Putnam42 Rockdale Walton Walker Monroe

37 Partial ozone and PM2.5 nonattainment county,
encompassing Plant Scherer. See 40 CFR 81.311. 38 The portion of Murray County designated as 8-hour

Rome

Floyd

ozone nonattainment includes only mountain peaks within

the Chattahoochee National Forest in Murray County at or

above 2,400 feet above sea level. See 40 CFR 81.311. 39 Ozone nonattainment areas are classified as "basic," "marginal," "moderate," "serious," "severe," or "extreme" based on the ozone design value at the time of designation. Areas with higher ozone design values are generally given longer to attain the standard but are subject to more prescriptive control measures.

40 69 Federal Register 34080. 41 Partial PM2.5 nonattainment county, encompassing
Plant Wansley. See 40 CFR 81.311. 42 Partial PM2.5 nonattainment county, encompassing
Plant Branch. See 40 CFR 81.311.

8

Figure 8: Georgia Nonattainment Areas43
43 Counties colored solid white and those not shown on the map are in attainment of all applicable air quality standards.
9

Measures and Targets
In general, a measure is an observable or computable quantity, such as the concentration of ozone in the air or vehicle miles traveled per day, that provides useful information regarding the state of the air quality or important factors that affect air quality. A target is both (1) a specified level for a measure and (2) a timeframe for achieving that level that should lead to air quality improvements. Although GRTA's jurisdiction currently includes only 13 of the 20 counties in the Atlanta ozone nonattainment area, GRTA staff believes it is appropriate to expand the scope of the measures to cover the entire nonattainment area. Therefore, the following measures and targets apply to the entire 20-county Atlanta ozone nonattainment area and are grouped under the headings "Air Quality," "Emissions," and "Activity."44
Air Quality Measures
GRTA's air quality measures and targets are based on EPD's ozone and PM2.5 monitoring data and on the National Ambient Air Quality Standards (NAAQS). These measures provide the ultimate assessment of the progress made in improving air quality in Georgia. The four air quality measures are described below.
Atlanta 8-Hour Ozone Standard Attainment Status
This measure tracks Atlanta's 8-hour ozone design value (see Footnote 16 on page 4 for a description of how to calculate the 8-hour ozone design value). In order for the area to attain the 8-hour ozone standard, its 8-hour ozone design value must be less than 85 ppb.

area has until June 15, 2007, to attain the 8-hour ozone standard. To achieve this goal, Atlanta's ozone design value at the end of the 2006 ozone season must be less than 85 ppb. Therefore, GRTA has adopted a target for this measure of 84 ppb in 2006. Although for the past three years this measure has been well below the preceding years, statistically speaking, it is very unlikely that it will meet the 2006 target.45 Therefore, sometime in 2006 or 2007, EPD will likely request that EPA change the Atlanta ozone nonattainment area's classification from marginal to moderate. This will allow Atlanta until June 15, 2010, to attain the 8-hour ozone standard, but it will also impose more requirements on the area.
For informational purposes, Figure 10 on page 11 shows the 8-hour ozone design value trends in the Macon, Murray County, and Chattanooga areas although they are not within GRTA's jurisdiction. Both Macon and Murray County were classified as "basic" 8-hour ozone nonattainment areas and given until June 15, 2009, to attain the 8-hour ozone standard. Hence, the ozone design values in these areas must be less than 85 ppb by the end of the 2008 ozone season. Although GRTA is not adopting targets for these areas, 84 ppb in 2008 is the de facto target in these two areas. The Chattanooga area, including Catoosa County in Georgia, is participating in an Early Action Compact with EPA which requires the area to attain the 8-hour ozone standard by December 31, 2007. Therefore, the de facto target in the Chattanooga area is 84 ppb in 2007. Figure 10 shows that as of 2005, the Macon, Murray County, and Chattanooga areas are all attaining the 8-hour ozone standard.

Figure 9 on page 11 shows Atlanta's 8hour ozone design values for the years 19952005. Based on its classification as a marginal 8-hour ozone nonattainment area, the Atlanta
44 Previous GRTA Air Quality Reports contained a fourth category called "Sources." However, this category and the associated measure have been eliminated for this year's report.

45 In order to achieve a design value of 84 ppb in 2006, the fourth highest 8-hour ozone concentration at the Confederate Avenue monitor near downtown Atlanta would have to be 73 ppb or less during the 2006 ozone season.
10

Figure 9: Atlanta 8-Hour Ozone Standard Attainment Status (1995-2005)

125 121

120

118

8-Hour Ozone Design Value (ppb)

115

113

109

110

110

105

105

100

95

90

107

99

2006

Target 93

91

91

85

84

80 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 Year
Design Value Target

Figure 10: 8-Hour Ozone Standard Attainment Status in Other Georgia Ozone Nonattainment Areas

110

105

105

104

8-Hour Ozone Design Value (ppb)

100

98

97

95

94 93

93 92

90

92

88

91

86 86

Macon & Murray Co.
Target

85

87

83

85

85

84 84

80

83 79

Chattanooga

Target

75 1997

1998

1999

2000

2001

2002

2003 Year

2004

2005

2006

2007

2008

2009

Macon Murray Co. Chattanooga Macon & Murray Co. Target Chattanooga Target

11

Atlanta Ozone Days
The peak daily 8-hour average ozone concentration may be classified into one of five46 discrete levels defined by the "ozone subindex" of EPA's "Air Quality Index" (AQI) as shown in Table 3 below. The AQI is an index for reporting daily air quality. It tells how clean or polluted the air is, and what associated health effects might be a concern. AQI sub-indices are calculated for five major air pollutants including ozone and particulate matter. Normally, the AQI for the pollutant with the highest sub-index is the one that is reported to the public. However, for purposes of this measure, the ozone sub-index was tracked for each day of the Atlanta ozone season (May 1 to September 30), regardless of whether it was the pollutant with the highest sub-index for the day. This allows GRTA to measure progress made in reducing ozone and PM2.5 levels separately.47

For purposes of this measure, the AQI ozone sub-index was retrieved from EPA's online "AirData" system for the years 1995 through 2005.50 The total number of days with the AQI ozone sub-index in the "green," "yellow," "orange," "red," and "purple" ranges were then totaled for each ozone season. The Atlanta Ozone Days measure for 1995-2005 is shown in Figure 11 on page 13. This measure has shown considerable improvement since 1998, as indicated by the increase in "green" days and decrease in "orange," "red" and "purple" days. The three most recent ozone seasons have averaged 140 days when peak ozone levels were "good" or "moderate," and 13 days when peak levels were "unhealthy for sensitive groups" or worse. GRTA has adopted a target of zero "orange" or worse ozone days per ozone season in the Atlanta area by the year 2015. (Note that it is possible to attain the 8hour ozone standard without achieving this target.)

Table 3: AQI Ozone Sub-Index

Color Green Yellow
Orange

Air Quality "Good"

Ozone Sub-Index
0 -- 50

"Moderate" 51 -- 100

"Unhealthy for Sensitive 101 -- 150
Groups"

Red

"Unhealthy" 151 -- 200

Purple

"Very Unhealthy"

201 -- 300

Maroon "Hazardous"

301

8-Hr Avg Ozone Concentration
(ppb)48 0 -- 64 65 -- 84 85 -- 104
105 -- 124
125 -- 374
405 (1-hour average)

EPA's Cautionary Statement49
None
Unusually sensitive people should consider reducing prolonged or heavy outdoor exertion.
Active children and adults, and people with respiratory disease, such as asthma, should reduce prolonged or heavy outdoor exertion.
Active children and adults, and people with respiratory disease, such as asthma, should avoid prolonged or heavy outdoor exertion; everyone else, especially children, should reduce prolonged or heavy outdoor exertion.
Active children and adults, and people with respiratory disease, such as asthma, should avoid all outdoor exertion; everyone else, especially children, should reduce outdoor exertion.
Everyone should avoid all outdoor exertion.

46 The sixth level of the AQI ozone sub-index is

determined using 1-hour average concentrations. 47 For more information on EPA's AQI, go to airnow.gov. 48 64 Federal Register 42530.

49 EPA, "Guideline For Reporting Of Daily Air Quality -
Air Quality Index (AQI)," EPA-454/B-06-001, 2006. 50 AQI ozone sub-index data were downloaded from

www.epa.gov/air/data/.

12

Figure 11: Atlanta Ozone Days Measure (1995-2005)

120

Number of Days in Year with AQI Ozone SubIndex in Indicated Range

98 100
89

80

80

76

76

74

69

65

62

60

62

54

51 46

55

52

44 40
17 20

41 41

25

35

44 46 38 13

40 29

2015 Target for 44 Orange + Red +
Purple

21

20 0

12 7

10

3

0

1

5

18

16

15

11

10 10

7

7

2

2 0

1

2 0

10

2 0

0

1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 ... 2015

Year

Good Unhealthy for Sensitive Groups Very Unhealthy

Moderate Unhealthy Target

Atlanta Annual PM2.5 Standard Attainment Status

Atlanta PM2.5 nonattainment area. Although Atlanta's annual PM2.5 design values have

This measure tracks Atlanta's annual PM2.5 design value (see Footnote 28 on page 6 for a description of how to calculate the annual PM2.5 design value). In order for an area to attain the annual PM2.5 standard, its annual PM2.5 design value must be less than or equal to 15.0 g/m3.
Figure 12 on page 14 shows the annual PM2.5 design values for the years 2001-2005 in Atlanta.51 The Atlanta area has until April 5, 2010, to attain the annual PM2.5 standard. To achieve this goal, Atlanta's annual PM2.5 design value at the end of 2009 must be less than or equal to 15.0 g/m3. Therefore, GRTA has adopted a target of 15.0 g/m3 in 2009 for the

trended downward since 2001, the design value has held constant for the past two years, and more rapid progress will be needed to achieve the 2009 target.
For informational purposes, Figure 13 on page 14 shows the annual PM2.5 design value trends in the Macon, Rome, and Chattanooga areas although they are not within GRTA's jurisdiction. As in the case of Atlanta, all three of these areas must attain the annual PM2.5 standard by April 5, 2010. Although GRTA is not adopting targets for these areas, 15.0 g/m3 in 2009 is the de facto target for this measure in these areas. As can be seen in Figure 13, all three areas have made significant progress towards meeting the standard since 2001.

51 The values in Figure 12 for years 2001-2004 are different than in previous reports due to an error in the way that this measure had been calculated in the past. Briefly, in past reports, the annual PM2.5 averages for all monitors in the Atlanta nonattainment area had been averaged together to calculate the annual PM2.5 design value. This should not have been done, and the values for

However, the design values increased between 2004 and 2005, indicating some degradation in recent PM2.5 air quality in these areas. The reason for this is uncertain but may have been caused by increased power plant SO2 emissions, leading to increases in sulfate-based PM2.5.

this measure have been corrected to reflect this.

13

Figure 12: Atlanta Annual PM2.5 Standard Attainment Status (2001-2005)

23

22 21.2
21

Annual PM2.5 Design Value (g/m3)

20

19.3

19 18.1

18

17.6

17.4

17

16

15

14

13 2001

2002

2003

2004

2005 Year

Design Value

2006

2007

Target

2009 Target
15.0
2008 2009

Figure 13: Annual PM2.5 Standard Attainment Status in Other PM2.5 Nonattainment Areas in Georgia (2001-2005)
20 19
19

Annual PM2.5 Design Value (g/m3)

18 18.4 17.6
17
16
15

16.9

16.4

16.1

16.1

15.6

15.2

16.1 15.8
15.5

2009 Target
15.0

14 2001

2002

2003

2004

2005 Year

2006

Macon Rome Chattanooga

2007 2008 Target

14

2009

Atlanta PM2.5 Days
Similar to the Ozone Days measure described on page 12, 24-hour average PM2.5 concentrations may be classified into one of six discrete levels defined by EPA's AQI PM2.5 sub-index as shown in Table 4 below. 52 For purposes of this measure, the AQI PM2.5 subindex was retrieved from EPA's on-line "AirData" system for the years 2000-2005.53 The total number of days with the AQI PM2.5 sub-index in the "green," "yellow," "orange," "red," and "purple" ranges were then totaled for each year. (The totals for each year did not always add up to 365 due to a few days with missing data.)
This measure is new in this year's report, and it complements the Atlanta Annual PM2.5 Attainment Status measure. Whereas the annual PM2.5 design value is one number averaged over

three years, this measure provides more detailed information on the number of days during an individual year when PM2.5 pollution was a health concern.
The Atlanta PM2.5 Days measure for 2001-2005 is shown in Figure 14 on page 16. This measure improved from 2000 through 2002, as indicated by the increase in "green" days and decrease in "yellow" and worse days. However, the number of "green" days declined in 2004 and recovered somewhat in 2005. The reason for this decline in PM2.5 air quality in Atlanta is uncertain but may have been caused by increased power plant SO2 emissions, leading to increases in sulfate-based PM2.5. GRTA has adopted a target of zero "orange" or worse PM2.5 days per year in the Atlanta area by the year 2015. (Note that it is possible to attain the annual PM2.5 standard without achieving this target.)

Table 4: AQI PM2.5 Sub-Index

Color Green Yellow
Orange

Air Quality "Good"

PM2.5 Sub-Index
0 -- 50

"Moderate" 51 -- 100

"Unhealthy for Sensitive
Groups"

101 -- 150

Red

"Unhealthy" 151 -- 200

Purple

"Very Unhealthy"

201 -- 300

Maroon "Hazardous"

301

24-Hr Avg PM2.5

Concentration

(g/m3)54

EPA's Cautionary Statement55

0.0 -- 15.4 None

15.5 -- 40.4

Unusually sensitive people should consider reducing prolonged or heavy exertion.

40.5 -- 65.4

People with heart or lung disease, older adults, and children should reduce prolonged or heavy exertion.

65.5 -- 150.4

People with heart or lung disease, older adults, and children should avoid prolonged or heavy exertion; everyone else should reduce prolonged or heavy exertion.

150.5 -- 250.4

People with heart or lung disease, older adults, and children should avoid all physical activity outdoors. Everyone else should avoid prolonged or heavy exertion.

250.5

Everyone should avoid all physical activity outdoors; people with heart or lung disease, older adults, and children should remain indoors and keep activity levels low.

52 For more information on EPA's AQI, go to airnow.gov. 53 The AQI PM2.5 sub-index data were downloaded from www.epa.gov/air/data/. 54 64 Federal Register 42530. 55 EPA, "Guideline For Reporting Of Daily Air Quality -
Air Quality Index (AQI)," EPA-454/B-06-001, February,
2006.
15

Figure 14: Atlanta PM2.5 Days (2000-2005)

Number of Days in Year with AQI PM2.5 SubIndex in Indicated Range

260

240

236

220

225

200

200

197

201

188

180

160

168

167

140

144

151

130

120

100

108

2015 Target for

80 Orange + Red + Purple Totals
60

Orange + Red + Purple

40

17

20

20

0

10

11

13

0

0

2000

2001

2002

2003

2004

2005

...

2015

Year

Good Unhealthy for Sensitive Groups Very Unhealthy

Moderate Unhealthy Target

Emissions Measures

are generally trending downward at the regional scale, trends at smaller geographic scales, such

GRTA's emissions measures focus on

as at the neighborhood level, may be different

regional-scale on-road mobile source emissions

depending on the intensity of vehicle activity

that contribute to ground-level ozone, PM2.5, mobile source air toxics (MSATs), and

and congestion in and around a given neighborhood.

greenhouse gases in the Atlanta ozone nonattainment area.56 These measures are based

Atlanta Total Daily Vehicle Emissions

on four sources of information: (1) summeradjusted daily vehicle miles traveled (VMT) data from GDOT;57 (2) MOBILE6-based emissions factors (i.e., amount of pollution emitted per VMT) developed by EPD; (3) ARC population estimates; and (4) Census Bureau population estimates. Note: These measures track emissions at the scale of the entire Atlanta

Total daily vehicle emissions of VOC,
NOx, primary PM2.5, SO2, NH3, MSATs, and CO2 are estimated for the 20-county Atlanta ozone nonattainment area by multiplying the
summer-adjusted average total daily VMT for
the area by the corresponding MOBILE6 emissions factors.58 The measures for 2001-

nonattainment area. Although vehicle emissions

58 MOBILE6 is a computer model developed by EPA for

56 For purposes of the emissions measures, the term
"vehicle" refers exclusively to on-road vehicles. 57 VMT are summer adjusted to account for slightly

estimating on-road motor vehicle emissions of NOx, VOC, PM2.5, MSATs, and CO2 among other pollutants. Emissions estimates depend on characteristics of the vehicle fleet (e.g., calendar year, age distribution),

greater travel observed on Atlanta roadways during the

operation (e.g., average speed), fuel (e.g., sulfur levels),

summertime. Summertime VMT is used because this is

controls (e.g., inspection and maintenance program), and

the time of year when ozone levels are highest.

meteorological conditions (e.g., air temperature).

16

2004 are compared to the baseline (year 2000) levels by dividing each year's values by the year 2000 values and converting the results into percentages. So, for example, Figure 15 shows that total daily vehicle VOC emissions in 2004 were 80% of the year 2000 level--a decrease of 20% over four years. The 2000-2004 trends are presented in the seven figures on pages 18 through 21.
Figure 15 and Figure 16 show the trends in total daily vehicle emissions of VOC and NOx in the 20-county Atlanta ozone nonattainment area from 2000 through 2004. Note that the values in 2001-2003 are slightly different than those contained in GRTA's 2004 Air Quality Report.59 These differences were caused by expanding the area covered by these measures from 13 to 20 counties. However, the conclusions remain the same: On-road vehicle VOC and NOx emissions in the Atlanta nonattainment area dropped significantly (roughly 20%) between 2000 and 2004, even as total population and VMT increased. Vehicles in Atlanta became much cleaner on average over this period for several reasons: (1) switching from a biennial to an annual vehicle inspection and maintenance program; (2) implementation of the National Low Emissions Vehicle program;60 (3) implementation of the second and third phases of Georgia's low-sulfur gasoline program; (4) the phase-in of more stringent federal "Tier 2" vehicle emissions standards;61 and (5) the continuous attrition of older, more-polluting vehicles from the fleet. These decreases contributed to improvements in ambient ozone levels in the Atlanta area and, since VOC and NOx are both precursors to secondary PM2.5 formation, likely also contributed to improvements in ambient PM2.5 levels.

Figure 17, Figure 18, and Figure 19 show the trends in total daily vehicle emissions of primary PM2.5, SO2 and NH3, respectively, in the 20-county Atlanta ozone nonattainment area over the 2000-2004 period. These measures are new in this year's report and have been included because Atlanta is now a PM2.5 nonattainment area. Motor vehicle emissions of primary PM2.5 originate from fuel combustion and tire and brake wear. Overall, primary PM2.5 emissions dropped almost 20% between 2000 and 2004 due mostly to increased market penetration of heavy-duty diesel vehicles powered by engines subject to the tighter emissions standards phased-in during the 1990s.62 This can be seen in Figure 17, where heavy-duty vehicle emissions of PM2.5 (light blue bars) are dropping much faster than for light-duty vehicles (dark blue bars). SO2 emissions initially increased from 2000 to 2002 as total daily VMT increased (see Figure 23 below) but then decreased significantly in 2003 and 2004 as fuel sulfur levels were reduced as part of Georgia's low-sulfur gasoline program. This is evident in Figure 18, which shows that lightduty vehicle SO2 emissions (dark blue bars) dropped rapidly after 2002. Vehicle-related NH3 emissions climbed by 12% from 20002004 as VMT increased. NH3 emissions are unregulated, and, in fact, EPA believes that NH3 emissions are enhanced slightly by the advanced emissions control systems that are designed to reduce other pollutants.63 Figure 19 shows that light-duty vehicles (dark blue bars) emit much more NH3 than heavy-duty vehicles (light blue bars).
Figure 20 shows the trend in total daily MSATs emissions in the 20-county Atlanta nonattainment area from 2000 through 2004.64

62 See, for example, www.epa.gov/otaq/cert/hd-cert/stds-

59 GRTA's 2004 Air Quality Report is available at

eng.pdf. 63 EPA, "MOBILE6.1 Particulate Emission Factor Model
Technical Description Final Report, M6.PM.001," Office

www.grta.org/news_section/2005_Publications/2004_AQ

of Transportation and Air Quality, EPA420-R-03-001,

_report_final.pdf. 60 For more information about the National Low

January, 2003. 64 For purposes of this measure, MSATs include benzene,

Emissions Vehicle program, see www.epa.gov/otaq/lev-

1,3-butadiene, formaldehyde, acetaldehyde, and acrolein.

nlev.htm. 61 For more information about the federal Tier 2 emissions

Diesel particulate matter is not included, which would significantly affect the heavy-duty vehicle fraction of this

standards, see www.epa.gov/tier2/.

measure.

17

This measure is new to the report and reflects GRTA's concern about whether Georgia residents are being exposed to unhealthy levels of these pollutants. This measure indicates that MSATs have decreased roughly 25% since 2000 due to the same programs that reduced VOCs (see above). Although MSATs are not regulated, increasingly stringent vehicle emissions standards have reduced VOC emissions, resulting in reduced MSATs. However, it should be noted that this measure tracks average area-wide vehicle emissions and does not address whether localized MSATs concentrations may have increased or decreased over this timeframe, for example, in the vicinity of heavily-congested transportation facilities.
Figure 21 shows the trend in total daily vehicle CO2 emissions in the 20-county Atlanta nonattainment area from 2000 through 2004.

This measure is also new to the report and is part of GRTA's effort to raise awareness about the importance of personal travel decisions in the generation of CO2 and other greenhouse gas emissions. Motor vehicle CO2 emissions depend on the amount of carbon in the fuel, the fuel consumed per mile driven (i.e., fuel economy), and the total number of miles driven. Since the average fuel economy of vehicles in Atlanta held fairly constant from 2000-2004, total CO2 emissions over that timeframe increased by 10% in direct proportion to the increase in total VMT.
GRTA has not yet adopted targets for these measures. Targets will be adopted after EPD develops ozone and PM2.5 attainment plans for Atlanta with associated motor vehicle emissions budgets.

Figure 15: Total Light-Duty Vehicle (LDV) and Heavy-Duty Vehicle (HDV) VOC Emissions in the 20-County Atlanta Nonattainment Area Relative to the Year 2000

110% 100%
90% 80%

100%

98%

92%

86%

80%

VOC Emissions Relative to 2000 Levels

70%

60% 50%

HDV LDV

40%

30%

20%

10%

0% 2000

2001

2002 Year

2003

2004

18

Figure 16: Total Light-Duty Vehicle (LDV) and Heavy-Duty Vehicle (HDV) NOx Emissions in the 20-County Atlanta Nonattainment Area Relative to the Year 2000

NOx Emissions Relative to 2000 Levels

110% 100%
90% 80% 70% 60% 50% 40% 30% 20% 10%
0%

100% 2000

97% 2001

94%
2002 Year

88% 2003

83% HDV LDV
2004

Primary PM2.5 Emissions Relative to 2000 Levels

Figure 17: Total Light-Duty Vehicle (LDV) and Heavy-Duty Vehicle (HDV) Primary PM2.5 Emissions in the 20County Atlanta Nonattainment Area Relative to the Year 2000

110% 100%
90% 80%

100%

96%

90%

84%

82%

70%

60% 50%

HDV LDV

40%

30%

20%

10%

0% 2000

2001

2002 Year

2003

2004

19

Figure 18: Total Light-Duty Vehicle (LDV) and Heavy-Duty Vehicle (HDV) Sulfur Dioxide (SO2) Emissions in the 20County Atlanta Nonattainment Area Relative to the Year 2000

SO2 Emissions Relative to 2000 Levels

110% 100%
90% 80% 70% 60% 50% 40% 30% 20% 10%
0%

100% 2000

103% 2001

104%
2002 Year

82% 2003

61%

HDV LDV

2004

Figure 19: Total Light-Duty Vehicle (LDV) and Heavy-Duty Vehicle (HDV) Ammonia (NH3) Emissions in the 20County Atlanta Nonattainment Area Relative to the Year 2000

120% 110% 100%

100%

104%

105%

107%

112%

NH3 Emissions Relative to 2000 Levels

90%

80%

70% 60% 50%

HDV LDV

40%

30%

20%

10%

0% 2000

2001

2002 Year

2003

2004

20

Figure 20: Total Light-Duty Vehicle (LDV) and Heavy-Duty Vehicle (HDV) Air Toxics Emissions in the 20-County Atlanta Nonattainment Area Relative to the Year 2000 (*Includes benzene, 1,3-butadiene, formaldehyde, acetaldehyde, and acrolein; but not diesel particulate matter)

110% 100%
90% 80% 70%

100%

97%

91%

82%

74%

MSATs* Emissions Relative to 2000 Levels

60% 50%

HDV LDV

40%

30%

20%

10%

0% 2000

2001

2002 Year

2003

2004

Figure 21: Total Light-Duty Vehicle (LDV) and Heavy-Duty Vehicle (HDV) Carbon Dioxide (CO2) Emissions in the 20-County Atlanta Nonattainment Area Relative to the Year 2000

CO2 Emissions Relative to 2000 Levels

120% 110% 100%
90% 80% 70% 60% 50% 40% 30% 20% 10%
0%

100% 2000

103% 2001

104%
2002 Year

105% 2003

110%
HDV LDV
2004

21

Atlanta Average Daily Vehicle Emissions per Person
Each of the emissions measures presented in the previous section has been reestimated on a "per person" basis in the measures below. This removes much of the effect of population growth on the trends and focuses the measures on the combined impacts of changes in vehicle technology and individual travel behavior. Average daily vehicle emissions per person of VOC, NOx, primary PM2.5, SO2, NH3, MSATs, and CO2 are estimated for the 20-county Atlanta ozone nonattainment area by dividing total daily lightduty vehicle emissions by the 20-county population. Light-duty vehicle emissions were chosen for these measures since personal travel (e.g., commuting, shopping, going to school) predominately uses light-duty vehicles and is the focus of programs that are aimed at reducing VMT by changing travel behavior. As before, the measures for 2001-2004 are compared to the baseline (year 2000) levels by dividing each year's values by the year 2000 values and

converting the results into percentages. The 2000-2004 trends are presented in Figure 22.
Figure 22 shows that light-duty vehicle emissions in the Atlanta area have declined even more on a per-person basis than total emissions over the 2000-2004 timeframe. This is because average VMT per person decreased by 9% (see Figure 24) while population increased by over 10% during this period. The increase in population resulted in a net increase in total VMT in the area (see Figure 23), partially offsetting the gains made through cleaner vehicles and the modest reductions in VMT per person over the period. Per-person emissions were six to ten percentage points lower than the corresponding average total daily emissions measures for the year 2004.
GRTA has not adopted targets for these measures. As with the total daily vehicle emissions above, GRTA will adopt targets for these measures after EPD develops ozone and PM2.5 attainment plans for Atlanta, including motor vehicle emissions budgets.

Figure 22: Average Light-Duty Vehicle Emissions per Person in Atlanta Relative to the Year 2000 (*The MSATs measure includes benzene, 1,3-butadiene, formaldehyde, acetaldehyde, and acrolein; but not diesel particulate matter)

LDV Emissions Per Person Relative to 2000 Levels

110% 100%
90% 80% 70%

100% 100% 100% 100%

100%100% 100%

98%

95% 96%

94%

98%99% 98%

94% 91%

87%

86%

99% 97%

87% 83%
79%

76%

101% 100%

80% 78%
73%

67%

60%

59%

50%

40%

30%
21%
20%

10%

0% 2000

2001

2002 Year

2003

2004

VOC NOx PM2.5 SO2 NH3 MSATs* CO2
22

13-county area, the 20-county average tends to

Activity Measures

track with the 13-county average. Over the

GRTA's activity measures focus on the usage of on-road motor vehicles and transit in the 20-county Atlanta ozone nonattainment area. These activities produce the emissions tracked in the measures reported in the previous section and are based on four sources of information: (1) summer-adjusted daily VMT data from GDOT;

entire period, VMT per person in the sevencounty area was greater than in the 13-county area, indicating that people in the seven outside counties travel more per day on average than people in the core counties. This is expected since homes and businesses are more spread out in the outlying seven-county area.

(2) transit ridership data from transit providers

Note that VMT per person in the 13-

operating in the area and/or the National Transit Database;65 (3) ARC population estimates; and

county area increased between 2003 and 2004. The reason for this increase is not known, and it

(4) Census Bureau population estimates. The

will be important to monitor this measure

activity measures are described below.

closely in the future since even relatively small

increases in VMT per person, when factored

Atlanta Average Total Daily VMT

together with a large and growing population,

Figure 23 on page 24 shows the trend in average total daily VMT in the 20-county Atlanta area and, for comparison, the former 13county Atlanta ozone nonattainment area from 1994 through 2004. Between 13 and 14% of total VMT occurs in the seven counties outside of the 13-county core. In both cases, average total daily VMT has increased by more than 30% over the past 10 years, and this trend is

translate into substantial increases in total VMT. For example, if average VMT per person in 2004 had remained at the 2003 level, total daily VMT in the 20-county area in 2004 would have been roughly 3 million lower. If the recent increase in this measure is real and sustained, it could exacerbate the Atlanta area's traffic congestion and air quality problems and require additional strategies to offset the increase.

expected to continue for at least the next 25

GRTA's 2004 Air Quality Report

years, so it is critical to Atlanta's air quality that

contained a target of 30.0 VMT per person per

vehicles continue to get cleaner in order to offset this increase. GRTA has not adopted a

day for the 13-county area, consistent with the 2004 Transportation MAP Report.66 Since this

target for this measure.

measure has been revised to cover the 20-county

area in this report, GRTA staff believes it is

Atlanta Average Daily VMT per

appropriate to revise the target as well. The 20-

Person

county values are on average 1% higher than the

Figure 24 on page 24 compares the trends in average daily VMT per person in the

13-county values, therefore, the target for this measure has been increased 1% to 30.3 in 2006.

former 13-county Atlanta nonattainment area,

the seven new Atlanta nonattainment counties,

and the entire 20-county Atlanta ozone

nonattainment area for 1994 through 2004.

Over this period, average daily VMT per person

in the 13-county core peaked at 34.7 in 1998

and then declined steadily to 31.6 in 2003. In

the seven new counties, VMT per person

continued to increase after 1998, peaking at 37.6

in 2001, and it has declined steadily since then.

Since over 85% of the VMT is generated in the

66 The 2004 Transportation Metropolitan Atlanta

65 For more information on the National Transit Database,

Performance (MAP) Report may be downloaded at www.grta.org/news_section/2005_publications/2004_Tra

go to www.ntdprogram.com.

nsportation_MAP_Report.pdf.

23

Figure 23: Atlanta Total Daily VMT (1994-2004)

180

Total Daily VMT (Millions)

160 140 120 100

113.6 98.4

118.1 102.9

124.3 108.4

130.4 113.7

136.7 119.2

137.6 119.0

141.1 121.6

145.1 124.3

146.4 125.4

147.6 126.2

153.5 131.7

80

60

40

20

0 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 Year
20-County Area 13-County Area

Figure 24: Atlanta Average Daily VMT per Person (1994-2004)

39

37.6

37

36.9 36.7
36.4

36.2

35.6

35.3

35.2

35

34.2

34.5

34.7 34.8 34.1 34.3

2006
35.4
20-County Area Target

33.6 33.8

33 32.9

33.2 32.9

33.1

33.8

33.3

33.4

33.2

32.9

32.5

32.6

32.0

32.9 32.2 32.3

31.6

31 30.3

Daily VMT Per Person

29

27

25 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 Year
13-County Area 7-County Area 20-County Area

24

Atlanta Regional Transit Ridership
The annual regional transit ridership measure represents the number of passengers who board the Atlanta region's buses and trains in a given year. The totals for the 20-county area are essentially the same as the totals for the 13-county core area since the vast majority of transit trips take place on the MARTA system. Passengers are counted each time they get on vehicles no matter how many vehicles they use to travel from their origin to their destination (i.e., "unlinked" transit trips). As shown in Figure 25, in the base year of 2001, there were 167 million passenger boardings. That number declined to 148 million boardings in 2004, the fewest boardings witnessed in the region since 1996. This trend appears despite an increase in the number of transit providers such as Xpress, Gwinnett County Transit, and C-Tran (Clayton County). The target for 2006 is 175 million transit trips. Such an increase in transit ridership would help offset potential increases in

VMT, with corresponding reductions in vehicle emissions.
Atlanta Regional Transit Ridership per Person
While the information in Figure 25 provides an indication of the trends in emissions reductions provided by transit ridership in the Atlanta nonattainment area, it does not necessarily indicate whether more or less people are choosing to utilize transit services. Figure 26 on page 26 better explains this by showing the average number of transit trips per person per year for fixed route (meaning all non demand-response) transit service in the 20county and 13-county Atlanta areas. While the absolute numbers are interesting, the trends are most important. By comparing the trends from 1994 to 2000 between Figure 25 and Figure 26, it can be seen that while overall ridership increased, transit trips per person stayed fairly constant over this timeframe. (Note: 1997 was an exception since fiscal year 1997 ridership data included the 1996 Olympics.) This means

Figure 25: Annual (Unlinked) Transit Trips in the Atlanta Area (1994-2004)

Annual Transit Ridership (Millions)

200

2006

180

173 161 166 170 167 166

Target

160 146 147 148

151 148

140

120

100

80

60

175
Target Vanpools GRTA Gwinnett CCT MARTA Bus MARTA Rail

40

20

0 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 Year

25

Average Annual Transit Trips per Person

Figure 26: Annual Unlinked Transit Trips per Person in the Atlanta Area (1994-2004)

60

52.0

50

48.7

46.9

45.9

45.5

46.9

46.6

46.0

42.6

41.1

40.2

40

41.0

40.8

40.2

43.7 42.3

38.2 36.9

37.8 36.5

32.9 31.7
30

20

10

0 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004
Year
20-County Area 13-County Area
that the growth in transit ridership in the Atlanta area from 1994 to 2000 basically kept pace with population growth. However, between 2001 and 2004 average transit trips per person declined due to decreases in ridership despite continued population growth. This decrease was probably due to a combination of several factors, including the economic downturn in the region, the scaling back of MARTA bus and rail service, increases in transit fares, and continued development in areas not served by transit.
Summary
In summary, GRTA has developed ten air-quality-related measures and targets for six of them. The measures and targets, summarized in Table 5 on page 27, focus on transportationrelated emissions, ground-level ozone, and fine particulate matter. However, GRTA may develop measures and targets for other emissions sources and other pollutants in the future.

26

Table 5: Summary of GRTA Air Quality Measures and Targets

Baseline

Measure

Description

Value Year

Atlanta 8-Hour Ozone Standard Attainment Status

Atlanta 8-hour ozone design value (ppb)

121 2000

Air Quality Measures

Atlanta Ozone Days

Number of days from May September with AQI Ozone Sub-Index in indicated range

60 2000 48 2000 32 2000 11 2000
2 2000

Atlanta Annual PM2.5 Attainment Status

Atlanta annual PM2.5 design value (g/m3)

21.2 2001

Number of days per year with Atlanta PM2.5 Days AQI PM2.5 Sub-Index in
indicated range
VOC

108 236 14
3 0 100%

2000 2000 2000 2000 2000 2000

Atlanta Total Daily Vehicle Emissions (relative to year 2000 levels)

NOx Primary PM2.5 SO2 NH3 MSATs

100% 100% 100% 100% 100%

2000 2000 2000 2000 2000

Emissions Measures

CO2 VOC/Person

100% 2000 100% 2000

Atlanta Average Daily Vehicle Emissions per Person (relative to year 2000 levels)

NOx/Person Primary PM2.5/Person SO2/Person NH3/Person MSATs/Person

100% 100% 100% 100% 100%

2000 2000 2000 2000 2000

CO2/Person

Atlanta Total Daily Average total daily summer-

VMT

adjusted VMT (millions)

100% 2000 141.1 2000

Activity Measures

Atlanta Average Daily VMT per Person
Atlanta Regional Transit Ridership
Atlanta Regional Transit Ridership per Person

Average daily summer-adjusted VMT per person
Number of transit trips per year (millions)
Average number of transit trips per person per year

33.4 2000 167 2001 38.2 2001

27

Update Value Year

91 2005

85 2005 54 2005 12 2005
2 2005 0 2005

17.5 2005

189 166
6 0 0 80% 83% 82% 61% 112% 74% 110% 73% 75% 74% 55% 101% 67% 100%

2005 2005 2005 2005 2005 2004 2004 2004 2004 2004 2004 2004 2004 2004 2004 2004 2004 2004 2004

153.5 2004

32.9 2004

148 2004

31.7 2004

Target Value Year

84 2006

N/A N/A

N/A N/A

2015

0

2015

0

2015

0

15.0 2009

N/A N/A

N/A N/A

2015

0

2015

0

2015

0

N/A N/A

N/A N/A

N/A N/A

N/A N/A

N/A N/A

N/A N/A

N/A N/A

N/A N/A

N/A N/A

N/A N/A

N/A N/A

N/A N/A

N/A N/A

N/A N/A

N/A N/A

30.3 2006

175 2006

N/A N/A

Initiatives
The following is a brief list of air quality related initiatives underway in the Atlanta area and those that are being considered by GRTA, EPD, ARC, and others, for future implementation.

buses in the area with emissions control devices. Another $4.7 million were programmed for the same period to help offset the incremental costs of ultra-low sulfur diesel fuel which must be used for some diesel retrofit technologies. EPD is the sponsor of these two projects.
Georgia Adopt-A-School Bus Program EPD

Existing Fuel and Vehicle Initiatives

has initiated a school bus retrofit program, also referred to as the Adopt-A-School Bus Program. It focuses on retrofitting school buses with

Georgia Low-Sulfur Fuel A state rule

diesel oxidation catalysts and diesel particulate

reducing NOx and VOC emissions from

filters and using cleaner fuels such as ultra low

gasoline-powered motor vehicles by lowering the sulfur content and Reid Vapor Pressure67 of

sulfur diesel. EPD has already worked with one school system, Clayton County, to retrofit 60 of

conventional gasoline in a 45-county area

their school buses with diesel oxidation

surrounding Atlanta.

catalysts. EPD received a grant from EPA's

Inspection and Maintenance Program Annual emissions control systems inspections of most gasoline-powered passenger vehicles and lightduty trucks registered in the 13-county Atlanta area.

Clean School Bus USA program, allowing it to select four school systems in the metro-Atlanta area to pilot the Adopt-A-School Bus Program. GRTA is contributing up to $20,000 to leverage up to $80,000 in federal CMAQ funds for the Adopt-A-School Bus Program.

Low Emission Vehicle Certification Program Provides tax credits for the purchase of dedicated alternative fuel low emission vehicles, for electric vehicle chargers purchased by businesses, for the purchase of zero emission vehicles, and for the conversion of conventional fueled vehicles to low emission alternative fueled vehicles.

Ultra-Low Sulfur Diesel Fuel (ULSD) The federal ULSD fuel program, when fully implemented and combined with heavy-duty diesel engine controls phased in through 2010, is expected to reduce PM and NOx emissions by 90% and 95%, respectively. EPD has established a statewide contract in 2005 through which state and local agencies may purchase

Diesel Engine Idle Emissions Reduction

ULSD over a year sooner than it would

Technology A 10% tax credit based on the

otherwise be available under the federal

cost of purchasing and installing certain diesel

program. Several agencies are utilizing this

emissions reduction technology equipment.

contract, including GRTA's Xpress regional

Heavy Duty "Not to Exceed" Standards In

express commuter coach system.

2001 Georgia adopted the California Air

Georgia Diesel Working Group The Georgia

Resources Board heavy-duty engines standards

Diesel Working Group formed in 2004 to

in advance of national standards adopted by

develop mechanisms and solutions to address

EPA in 2005.

and reduce the contribution of diesel engines to

Congestion Mitigation and Air Quality

Georgia's air quality problems.

Improvement Program (CMAQ) Retrofit Projects A total of $2.5 million in federal CMAQ funds were programmed for fiscal years

Potential and/or Future Fuel and Vehicle Initiatives

2005 and 2006 in the Atlanta Transportation Improvement Program for retrofitting school

Clean Construction Diesel Retrofit Program EPD is evaluating the feasibility of a heavy-duty

67 Reid Vapor Pressure is a measure of how quickly a fuel will evaporate. The higher the Reid Vapor Pressure, the

diesel retrofit program for nonroad construction diesel vehicles in the nonattainment area. The

faster the fuel evaporates.

28

result of the program would be a reduction in ozone, NOx, VOC, CO, PM, and air toxics.
Inspection and Maintenance Program The current Atlanta I/M program may be implemented in the seven additional counties within the expanded 20-county 8-hour ozone Atlanta nonattainment area.
Accelerated Vehicle Retirement Programs Programs that help purchase older high emitting vehicles for a fixed amount of money to permanently "retire" them by crushing them or disabling them and selling the remaining parts with the goal of removing high-emitting vehicles from the fleet and spurring turnover to a newer fleet.
Existing Land Use Initiatives
ARC/GRTA Joint Land Use Strategy The purpose of the Joint Land Use Strategy is to ensure the land use policies represented in the Regional Transportation Plan (RTP) and the Regional Development Plan (RDP) will effectively and successfully guide future development in Atlanta.
Developments of Regional Impact (DRI) GRTA's legislation requires that it review DRI's within its jurisdiction with the purpose of approving or disapproving the use of state and federal funds to create transportation services and access that may be required as a result of the DRI. The goals of the review are protecting and efficiently allocating limited state and federal resources, promoting compliance with regional transportation plans and air quality standards, and furthering GRTA's mission and goals.
Atlantic Steel Redevelopment The redevelopment of this former steel mill site was approved by the EPA as a Transportation Control Measure (TCM) in the Georgia state implementation plan. It is the first TCM in the country to explicitly recognize the air pollution benefits of a well-designed, mixed-use, transitoriented development. Part of the redevelopment plan included the construction of the 17th Street Bridge connecting the development to the Arts Center MARTA rail

station. The bridge design includes wide pedestrian walkways and dedicated bus lanes to encourage alternative modes of transportation in the area.
Southern Regional Accessibility Study ARC, in partnership with two other Regional Development Centers, six counties and twentynine municipalities, is conducting a study of existing and proposed land use and transportation policies, strategies and plans in the southern portion of the metro Atlanta region. The results and recommendations of the Southern Regional Accessibility Study will be critical to the update of ARC's Regional Development and Regional Transportation Plans. The study began in October 2005 and will be completed in February 2007.
Livable Centers Initiative The ARC's Livable Centers Initiative promotes quality growth in the region by encouraging greater mobility and livability within existing employment and town centers through enhancements of the already existing infrastructure instead of building anew.
Transportation Initiatives
Congestion Mitigation Task Force The Congestion Mitigation Task Force was formed in March 2005 by Governor Perdue to develop recommendations for cooperatively managing traffic congestion in metro Atlanta. The Task Force was comprised of representatives from ARC, GDOT, GRTA, and the State Road & Tollway Authority. The Task Force was charged by the Governor to: (1) Develop strategies, benchmarks and goals to costeffectively reduce traffic congestion in the metro-Atlanta non-attainment area; (2) develop a cost/benefit methodology to be applied to project selection; and (3) present recommendations to the four agencies for incorporation into the regional and statewide planning processes. The Task Force issued its final report in December 2005.
Traffic Incident Management Task Force The Traffic Incident Management Enhance Task Force (TIME) was formed to address the critical issues related to incident management in the region. The Task Force is made up of concerned

29

incident responders from transportation agencies, fire, rescue, police, towing, emergency medical services, etc., and its mission is to develop and sustain a region-wide traffic incident management program to facilitate the safest and fastest roadway clearance of traffic accidents while lessening the impact on emergency responders and the motoring public.
Transit Planning Board The Transit Planning Board is a partnership between state and local governments that will establish and maintain a seamless, integrated public transportation network for the Atlanta region. An initial phase of at least two years will be required for planning. A second long-term phase is envisioned as an established regional body (the Transit Services Board), which would be implemented if/when a new funding mechanism is recommended by the Transit Planning Board and approved.
Xpress Regional Express Commuter Coach System GRTA has begun implementing Xpress, a regional express commuter coach system serving the Atlanta nonattainment area. Of the 20 nonattainment counties in the Atlanta area, 11 have reached an agreement with GRTA to participate in the Xpress system and have committed $21 million for capital and operating assistance in exchange for arterial roadway improvements. Forty-eight coaches were purchased and delivered to the system in late 2003. Ten additional coaches, for use by Gwinnett County Transit, were ordered and delivered in 2005. Twenty additional coaches were delivered in the fall of 2005. By early in 2006, 14 routes had been implemented and over 300,000 passenger trips had been made by Xpress riders.
Regional Vanpool Program In 2003, GRTA assumed the responsibility for the State Employees Commuter Assistance Program and the continued operation of the state vans. GRTA also launched a regional vanpool program.
Regional HOV Network The existing Atlanta area HOV network consists of 90 lane-miles. GDOT has performed a study and developed a strategic plan for expanding the HOV system in the Atlanta region. This plan will be considered

in the development of Mobility 2030, the region's next RTP, and the 2005-2010 Transportation Improvement Program (TIP).
Regional Commuter Rail System GRTA, GDOT and the Georgia Rail Passenger Authority form the Georgia Rail Passenger Program which has identified seven commuter rail corridors. The Federal Environmental Assessment process was completed in two corridors; the Macon-Atlanta and the AthensAtlanta. GDOT has had discussions regarding the Lovejoy-Atlanta segment of the Macon corridor with the owning railroad, Norfolk Southern Corporation.
Northwest I-75/I-575 HOV/BRT Study This is a combination of GDOT's I-75 HOV Project with GRTA's Northwest Connectivity Study to create alternative transportation within the Town Center, Cumberland-Galleria and Midtown Atlanta transportation corridor. The GRTA Board selected Bus Rapid Transit (BRT) as the Locally Preferred Alternative, and the next two years will focus on identifying, evaluating and mitigating environmental impacts to complete a federal Environmental Impact Statement. After 2011, as the project phases are completed, peak-period transit users and carpoolers will be able to significantly reduce travel time along the I-75 northwest corridor as compared with driving alone.
Breeze Card Regional Task Force MARTA has begun a replacement of its ageing transit fare collection system using smartcard based technology. The new system, branded BreezeTM is expected to be operational by August of 2006. A Breeze Card Regional Task Force has been established by MARTA to work with GRTA, GCT, CTRAN, CCT, SRTA, Hartsfield/Jackson Airport, and others to extend MARTA's smartcard systems for use by the entire region. Smart Card Technologies are key to the implementation of a seamless transit infrastructure for the region. A regional implementation of a common smartcard will enable customers to transfer from one transit system using a single fare card. The new system will provide a foundation for the implementation of innovative fare structures

30

across multiple jurisdictions, and help agencies meet federal reporting requirements.
State of Georgia Work Away Program Work Away is a management option provided to the State of Georgia employees that allows selected employees to telework for one or more days per week, or other time period.
Fast Forward Congestion Relief Program On April 14, 2004 Governor Perdue introduced the Fast Forward Congestion Relief Program to address Georgia's growing congestion problems. Fast Forward is a comprehensive 6year, $15.5 billion transportation program that will relieve congestion and spur economic growth through the acceleration of existing projects.
Other Existing and Potential Transportation Initiatives
Atlanta Regional Commission's Bicycle Suitability Maps ARC has produced bicycle suitability maps for every county in the Atlanta region as well as the City of Atlanta to assist the cycling community in determining the safest and most logical paths. The maps identify existing on-road bicycle facilities, off-road paths, transit stations, bus routes, and various points of interest.
The Clean Air Campaign The Clean Air Campaign is a not-for-profit organization that works to reduce traffic congestion and improve air quality through a variety of voluntary programs and services.
C-TRAN Local bus service for Clayton County operated as a partnership between GRTA and Clayton County.
Regional Transit Action Plan (RTAP) The RTAP is a two-year study that has recommended the foundations for a seamless, integrated public transportation network in the Atlanta region. Part of this study developed the blueprint for the Xpress regional express commuter system. The Concept Plan for the RTAP has been completed and has been incorporated into the planning of ARC's Mobility 2030 and 2005-2010 TIP.

Regional Traffic Operations Initiative In 2003, Governor Perdue announced an initiative to improve metro Atlanta's traffic signal operations. GRTA, GDOT and ARC partnered to create a Task Force spearheading regional efforts on short range traffic operations projects to improve traffic flow and reduce traffic congestion. As a result, a regional corridor prioritization list for signal retiming has been prepared, five signal system retiming projects are completed, and GDOT has selected consultants for program management and signal timing.

31

Appendix
For informational purposes, Table 6 presents the total number of observations, or "readings," of the 8-hour average ozone concentration at each of the 11 monitors in the Atlanta ozone nonattainment area from May 1 through September 30, 2005. (Previous reports also included a table of 1-hour ozone readings. However, since EPA has revoked the 1-hour ozone standard, GRTA will no longer track these data.) The table also lists the total number of readings above and below the level of the 8hour ozone standard (= 84 ppb).
This table shows that the percentage of ozone readings that exceeded the level of the standard in Atlanta from May through September 2005 was relatively small, averaging 0.37%. However, note that each reading is an average over eight hours of monitoring, so that one reading above 84 ppb actually represents an

eight-hour long episode of potentially unhealthy air quality. In addition, these data do not indicate the extent to which the readings exceeded or were below 84 ppb, nor the associated health implications. Furthermore, the totals include nighttime observations when ozone levels are typically lowest, and when people are less likely to be outdoors where they could be exposed to ozone. If, for example, the readings were restricted to the period from 6AM to midnight, the resulting average number of readings above 84 ppb would increase to 0.49%.
It should also be noted that these numbers are based on 2005 data only, and they are therefore only part of the data necessary for determining attainment of the 8-hour ozone standard. For an area to attain the 8-hour standard, the three-year average of the annual fourth-highest daily maximum 8-hour average ozone concentration in the area must be less than or equal to 84 ppb.

Table 6: Number of Atlanta 8-Hour Average Ozone Readings Above and Below 84 ppb for May through September

2005

Number of

8-Hour Avg

Number of

Percent of

Number of

Percent of

Ozone

Readings

Readings

Readings

Readings

Monitor Location

Readings

> 84 ppb

> 84 ppb

84 ppb

84 ppb

Confederate Avenue

3,660

25

0.68%

3,635

99.32%

Conyers

3,608

16

0.44%

3,592

99.56%

Douglasville

3,647

30

0.82%

3,617

99.18%

Fayetteville

3,661

10

0.27%

3,651

99.73%

Kennesaw

3,667

3

0.08%

3,664

99.92%

Lawrenceville

3,515

2

0.06%

3,513

99.94%

McDonough

3,661

24

0.66%

3,637

99.34%

Newnan

3,667

0

0.00%

3,667

100.00%

South DeKalb

3,626

20

0.55%

3,606

99.45%

Tucker

3,551

12

0.34%

3,539

99.66%

Yorkville

3,660

4

0.11%

3,656

99.89%

Totals

39,923

146

0.37%

39,777

99.63%

32