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Communities Better Plan for Transportation That Protects Air Quality' 
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United States General Accounting Office:



GAO:



Testimony:



Before the Committee on Environment and Public Works, U.S. Senate:



For Release on Delivery:



Expected at 9:30 a.m., EDT

Tuesday, July 30, 2002:



ENVIRONMENTAL PROTECTION:



The Federal Government Could Help Communities Better Plan for 

Transportation That Protects Air Quality:



Statement for the Record by John B. Stephenson:



Director, Natural Resources and Environment:



GAO-02-988T:



Mr. Chairman and Members of the Committee:



We are pleased to have the opportunity to comment on how transportation 

can affect a communitys air quality. My statement is based primarily 

on our October 2001 report on these issues.[Footnote 1] As you know, 

since World War II, cities and suburbs grew, more roads were built, and 

more people had to rely on cars and buses for work, shopping, and 

business. In fact, in the last 30 years, the total number of vehicle 

miles driven grew 4 times faster than the rate of population growth, 

increasing to 2.6 trillion miles per year. The fuel these cars, buses, 

and other vehicles burn emits substances into the air that harm human 

health and the environment. Despite regulations limiting these 

emissions and improved vehicle and fuel technologies, the air in 

numerous cities and towns still does not meet air quality standards. 

Therefore, communities may look to change their future transportation 

and land use plans as a means to curb emissions.



Recognizing that transportation can affect the nations efforts to 

improve air quality, the Congress has provided funds for projects that 

protect air quality. Now, as the Congress begins the work of 

reauthorizing the surface transportation programs,[Footnote 2] it will 

have to consider whether to continue or revise these initiatives. To 

help inform this work, we are commenting on (1) the impacts of surface 

transportation on air quality; (2) the benefits and limits of key 

federal surface transportation and clean air requirements and programs 

designed to mitigate these impacts; and (3) ways the federal government 

can use these requirements and programs to further reduce these 

impacts. Our findings and recommendations are based to a large extent 

on the results of a survey we conducted in 2001 of all of the 341 

metropolitan planning organizations in existence at that time (295, or 

87 percent, responded). These organizations are responsible for 

developing transportation plans and ensuring that they do not worsen 

air quality. We surveyed these planners on their views about the types 

of transportation projects undertaken in their areas, how concerns 

about air quality impact their plans, and how the federal government 

could help them further assess alternative land use strategies when 

developing their transportation plans, among other things.



In summary, we found the following:



Vehicle emissions contain substances, including carbon monoxide, 

nitrogen oxides, and volatile organic compounds, that degrade air 

quality, thereby threatening public health and the environment. 

Vehicles currently account for about one-third to one-half of these 

pollutants, and the risk they pose to public health is substantial. 

Epidemiological and other studies have consistently found that 

breathing emissions containing these compounds contributes to 

respiratory and other health problems, including the possibility of 

cancer and increased incidence of childhood asthma. Vehicle emissions 

can also pose risks to the environment by, for example, harming 

vegetation and causing crop damage. Regulatory limits on emissions, as 

well as cleaner fuels and engines, have significantly decreased these 

harmful substances since 1970, despite the increase in the number of 

vehicles and in the time they spend on the roads. But EPA estimates 

that better technology alone will not fully compensate for the 

increasing vehicle travel and emissions expected in the future.



Provisions in the clean air and surface transportation laws have helped 

encourage transportation planners to look for ways to curb harmful 

emissions, but predominantly in areas that already suffer pollution 

problems. The provisions have not encouraged those areas with little 

pollution that still expect significant growth--and that may have the 

greatest potential to influence it--to grow in ways that preserve clean 

air. For instance, the Clean Air Act requires transportation planners 

to demonstrate that their plans and programs will not worsen air 

quality, but only in areas with current or prior air quality problems. 

Few planners in areas with clean air try to assess how changing land 

use or transportation plans can help them maintain the healthy air 

quality in their communities, according to our survey. Many of those 

planners that have to demonstrate to the Department of Transportation 

(DOT) that their plans will protect air quality have had difficulty 

doing so, potentially limiting conformitys effectiveness. Provisions 

of the surface transportation laws, in particular the Congestion 

Mitigation and Air Quality Improvement Program, also primarily target 

areas with air quality problems to help them avoid further degradation, 

but do less to target areas with clean air to help them prevent the 

pollution in the first place. In addition to these statutory 

provisions, DOT and the Environmental Protection Agency (EPA) have 

implemented a number of funding, technical assistance, and public 

education programs aimed at minimizing transportations effects on air 

quality. But some initiatives have had limited funding, or were only 

implemented in a few communities.



The Congress and federal agencies have opportunities to provide 

transportation planners and communities more help in considering the 

environmental impacts of their transportation and land use decisions. 

For example, the transportation planners responding to our survey 

identified several areas in which financial and technical assistance 

would help them assess these impacts. In addition, in our 2001 report, 

we made a number of recommendations on ways to leverage the benefits of 

current laws and programs designed to help limit or prevent the impacts 

of land use and transportation on air quality or to consider new 

programs to achieve this outcome. We have summarized some of these 

recommendations in our statement today.



Air Pollution from Vehicle Emissions Will Continue to Pose Health and 

Environmental Risks to Some Communities, Despite New Technology and 

Emissions Limits:



Vehicles emissions contribute to air quality degradation and, as a 

result, threaten public health and the environment. For example, in 

1999, emissions from vehicles contributed about 51 percent of the 

carbon monoxide, 34 percent of the nitrogen oxides, and 29 percent of 

the volatile organic compounds in the nations air, according to EPA 

(see fig. 1).[Footnote 3]



Figure 1: Proportion of 1999 Motor Vehicle Emissions for Carbon 

Monoxide, Nitrogen Oxides, and Volatile Organic Compounds:



[See PDF for image]



Source: EPA.



Note: The most current data available are for 1999.



[End of figure]



In addition, the Department of Energy estimates that in 1999 alone, 

vehicle emissions, primarily from automobiles and light trucks, 

contributed about 60 percent of the total carbon emitted by the 

transportation sector.



Over the past 50 years, epidemiological and other studies have 

consistently found that these types of pollutants from vehicle 

emissions pose health risks. Carbon monoxide can damage cardiovascular 

and nervous systems. Nitrogen oxides and volatile organic compounds 

react with sunlight to form ozone, which, along with particulate 

matter, can damage lung tissue, aggravate respiratory disease, and lead 

to premature deaths. These pollutants also increase susceptibility to 

respiratory infection, compromise immune systems, and in some cases, 

increase the risks of cancer, according to EPA.



In addition to health problems, vehicle emissions adversely affect the 

environment by harming vegetation, damaging water resources, and 

contributing to global climate change. Emissions increase plant 

vulnerability to disease, potentially causing long-term damage to 

forests. According to EPA, air pollution from motor vehicle emissions 

annually causes about $2.5 billion to about $4.5 billion in crop 

damage. Air pollutants also damage sensitive waters, such as bays and 

estuaries. For example, nitrogen oxides from vehicle emissions 

deposited into the Chesapeake Bay have caused algae blooms that 

threaten the fish hatchery and degrade spawning habitat. Furthermore, 

motor vehicles emit carbon dioxide, a greenhouse gas and a factor in 

global climate change, according to the National Research 

Council.[Footnote 4] Although the effect of this change on human health 

and the environment is uncertain, it is believed to be significant.



The good news is that harmful vehicle emissions have declined 

significantly since 1970 and are expected to continue downwards because 

of cleaner fuels and better regulatory and technological controls. For 

example, stricter emissions limits for sport utility vehicles and 

light-duty trucks are scheduled to go into effect in 2004. EPA 

estimates that over the next 30 years these new standards will 

significantly reduce emissions of nitrogen oxides from vehicles by 

about 74 percent. Nevertheless, EPA also estimates that by 2005, the 

benefits gained from technological advances may not be enough to 

compensate for the increases in vehicle use. A study of emissions in 

Tennessee also predicts that stricter emissions limits would not be 

sufficient to offset the increased vehicle use and resulting nitrogen 

oxide and volatile organic compound emissions in its major cities of 

Memphis, Nashville, and Knoxville.[Footnote 5]



It is not only communities with current pollution problems that need to 

be concerned. A significant number of new communities will soon face 

pollution problems when EPA implements stricter limits on ozone and 

particulate matter around the end of 2004, as planned, in order to 

better protect public health from these harmful substances.[Footnote 6] 

EPA estimates that approximately 334 of the 3,141 counties nationwide 

will not meet the new ozone limit, as figure 2 shows.[Footnote 7]



Figure 2: Areas with Current and Potential Ozone Problems:



[See PDF for image]



Source: GAO analysis of EPA data.



[End of figure]



While the number of counties not meeting the standard may be relatively 

small, the number of people that will be living with these air quality 

problems is significant. For example, in 1999, EPA estimated that twice 

as many people live in areas that are expected to violate the new 

standard as compared to the number that live in areas violating the 

current standard--123 million people, or 44 percent of the nations 

population, compared with 54 million. This development, coupled with 

the fact that the technological solutions needed to achieve relatively 

smaller emissions reductions may become too costly, will require 

communities to look for other ways to reduce emissions. These 

alternatives could include altering their future transportation and 

land use plans.



Federal Laws and Programs Linking Transportation to Improved Air 

Quality Have Helped Targeted Communities Control Pollution but Could Be 

More Comprehensive:



Both the clean air and surface transportation laws established 

requirements and programs that have helped to reduce harmful vehicle 

emissions, but these have focused on managing existing pollution and do 

not provide areas with clean air an incentive to preserve it. DOT and 

EPA also have initiatives underway, including joint projects, that 

encourage transportation planners and communities to consider how their 

anticipated transportation systems and projects will affect air 

quality. However, DOT has limited discretion over one of its grant 

programs, thereby raising questions about whether funds are used most 

effectively, and EPA has limited funding for its initiatives and 

therefore has supported only a small number of communities.



The Clean Air Act Requires Planners to Ensure Transportation Designs 

Will Not Worsen Air Quality, but Only in Areas that Already Have 

Pollution Problems:



A provision in the Clean Air Act addresses the link between 

transportation and air quality--the conformity demonstration 

requirement. Generally speaking, under this requirement, 

transportation planners in an area with air quality problems must 

estimate the emissions resulting from their transportation plans and 

programs and demonstrate that they do not exceed the vehicle emissions 

ceiling, or budget, approved for that area in the state implementation 

plan for achieving air quality standards.[Footnote 8] If they cannot do 

so, they must adjust their transportation plans or their area cannot, 

with limited exceptions, spend federal funds on highway or transit 

projects that will exacerbate or create air quality problems.[Footnote 

9]



In our 2001 survey, 56 percent of the 134 transportation planners in 

areas of poor air quality, and thereby required to demonstrate 

conformity, said that they made at least moderate changes to their 

transportation plans and programs to reduce emissions. These changes 

could include, for example, adding more transit projects, bike and 

pedestrian facilities, or intelligent transportation systems like 

electronic toll collection systems on highways. Furthermore, the 

conformity requirement provided an incentive for planners in areas with 

air quality problems to go beyond just looking for ways to make changes 

in their transportation plan to reduce emissions. Some of these 

planners also assessed whether changing local land use plans could have 

an even more dramatic effect on transportation plans and prevent 

pollution by reducing reliance on cars. In fact, 46 percent of the 134 

planners said that they evaluated the emissions from the mix of 

transportation projects generated from alternative land uses, as shown 

in figure 3.



Figure 3: MPOs in Areas with Air Quality Problems That Have Modeled 

Emissions from Different Land Uses:



[See PDF for image]



Note: The boundaries covered by the planning organizations are based on 

survey data and may not reflect exact borders. We designated an 

organizations entire boundary as being an area with air quality 

problems if any one county within the borders has problems. The results 

from Alaska are not included.



Source: GAO analysis of survey data.



[End of figure]



In contrast, transportation planners in areas with good air quality 

that did not have to meet the conformity requirement seemed to have 

little incentive to assess emissions from alternative land uses as a 

means to preserve their air quality. In fact, only 8 percent of these 

155 planners reported assessing emissions from the mix of 

transportation projects generated from alternative land uses, as shown 

in figure 4, compared with the 46 percent of planners in areas with air 

quality problems. By not conducting these assessments, the localities-

-many of which could be facing rapid growth in the future--may have 

missed an opportunity to plan their growth--and the transportation 

systems to support it--in ways that preserve clean air.



Figure 4: MPOs in Areas Without Air Quality Problems that Have Modeled 

Emissions from Different Land Uses:



[See PDF for image]



Note: The boundaries covered by the planning organizations are based on 

survey data and may not reflect exact borders. We designated an 

organizations entire boundary as being an area with air quality 

problems if any one county within the borders has problems. The results 

from Alaska are not included.



Source: GAO analysis of survey data.



[End of figure]



While recognizing that the conformity requirement has encouraged 

certain communities to look for ways to reduce emissions, only 31 

percent of the planners responding to our survey found the process of 

demonstrating conformity to be effective in helping their areas achieve 

air quality goals (40 percent found it to be ineffective). Managers of 

state air quality programs, who we surveyed separately, expressed 

similar views about the effectiveness of the process. Planners, 

managers, and DOT officials identified several difficulties in 

executing the various steps needed to demonstrate conformity. These 

include the following:



The required time frames for updating transportation plans and testing 

conformity do not match those for updating an areas vehicle emissions 

budget in the air quality plan, and this difference can further 

complicate efforts to meet the conformity requirement, according to DOT 

officials. For example, when planners in the Washington, D.C., 

metropolitan area had to update their transportation plans and test for 

conformity, they had to use the most current data on the types of 

vehicles driven in the area. That data showed an unexpected increase in 

the number of sport-utility vehicles on the roads and, consequently, 

projected emissions were higher. To ensure conformity did not lapse, 

the planners had to try to find additional ways to alter their 

transportation plans to achieve the necessary emissions offsets. 

Because the areas air quality plan was not updated at the same time, 

it was not possible to assess whether the emission budgets needed to be 

revised to reflect the increased vehicle emissions.



Planners responded in the survey that they could use additional 

technical assistance and training to help them better understand the 

models used to compute emissions expected from their transportation 

plans, thereby helping them better demonstrate conformity.



Planners furthermore reported that the public lacks knowledge about the 

air quality impacts of their transportation choices. This may make it 

less likely that they will support transportation changes that better 

protect air quality.



Planners responded that land use decisionmakers are not systematically 

involved in the conformity process, despite the belief that certain 

land uses can impact regional air quality. Therefore, land use 

decisionmakers may be less likely to support changes that better 

protect air quality, such as denser housing and development in older, 

urban areas rather than scattered development on undeveloped land.



According to DOT program managers, some planners have found the 

requirement to update their transportation plans and meet the 

conformity test at least every 3 years to be too burdensome. Because of 

the complexity and time involved in preparing the plan and 

demonstrating conformity, it can take some areas more than 3 years to 

complete their plan updates, after which time they need to begin the 

update process all over again. The tight time frame inhibits them from 

devoting their attention or resources to developing more strategic 

transportation solutions or adopting new and better models for 

assessing emissions and analyzing transportation plans, among other 

things.



Resolving these issues and improving the effectiveness of the 

conformity process could be even more important because of the new 

counties that are expected not to meet the new ozone and particulate 

matter standards. Having to demonstrate conformity will be among the 

challenges these counties will have to face. At the chairmans request, 

we are initiating a more comprehensive review of the conformity 

requirements effectiveness, impact on transportation planning, and 

possible improvements.



Federal Surface Transportation Laws Created Programs to Protect Air 

Quality but Some Are Not Comprehensive Enough to Prevent Pollution:



ISTEA, and its successor, TEA-21, included provisions to promote 

transportation plans and programs that better protect air quality. The 

largest of these is the Congestion Mitigation and Air Quality 

Improvement program (CMAQ), receiving $8.1 billion through 2003. This 

program provides federal funds for transportation projects to reduce 

emissions and congestion in areas with poor air quality. For example, 

Boulder, Colorado, used CMAQ to partially fund a transit service that 

helps connect residents to employment centers and retail districts. 

Because this service transports nearly 10,000 riders per day, it has 

helped the city meet its clean air and congestion relief goals.



Although CMAQ encourages projects that reduce emissions, it targets 

areas with existing air quality problems, and provides less of an 

incentive to areas with clean air that may have emerging air quality 

problems.[Footnote 10] This is important because implementation of 

EPAs new limits on ozone and fine particulate matter will increase the 

number of communities with air quality problems and may increase demand 

for the programs limited funding (see fig. 2). Furthermore, DOT 

program managers observed that communities tend to use their funds on 

tried and true projects, such as carpool lanes, and overlook other, 

more innovative projects, such as cleaner diesel engines, that could 

potentially achieve greater emissions reductions per dollar. In 

addition, the formula used to distribute CMAQ funds takes into account 

whether an area has an ozone or carbon monoxide problem, but not a 

particulate matter problem, even though this pollutant can pose similar 

health risks.



TEA-21 also created the Transportation and Community and System 

Preservation Pilot program to help planners and localities improve the 

efficiency of the transportation system and reduce the environmental 

impacts of transportation, among other objectives. However, program 

managers may not be able to ensure funds are used most effectively on 

projects that could best demonstrate the linkages between 

transportation, air quality, and land use because most of the funds 

were already designated, or earmarked, to projects before they were 

reviewed using the competitive selection factors.



Other DOT and EPA Initiatives Show Promise, but Scope and Funding Are 

Limited:



In addition to the programs authorized under TEA-21, a number of 

funding, technical assistance, and outreach initiatives have helped 

localities minimize the impacts of transportation on air quality. For 

example:



Funding. EPA has programs to encourage transportation projects that are 

more protective of air quality. The agencys Clean Air Transportation 

Communities grants program, implemented in 2001, provided $1.27 million 

in seed money, technical assistance, and recognition for transportation 

projects that reduce emissions. For example, one project will encourage 

a car-sharing program to introduce new low-emissions vehicles. EPA also 

created the Mobile Source Outreach Assistance program, funded at 

$770,000 in fiscal year 2001, to help educate communities about 

transportation choices that reduce vehicle miles and emissions.



Technical assistance. DOT and EPA have a number of joint technical 

assistance efforts underway to help transportation planners consider 

air quality impacts. For example, the agencies (1) are issuing guidance 

to better clarify the modeling needed to comply with the conformity 

requirement and (2) initiated the Travel Model Improvement Program to 

update transportation models so that they help planners better perform 

travel-related technical analyses.



Outreach. EPA has several initiatives aimed at encouraging planners and 

communities to think about alternative land uses as a way to better 

protect the environment, initiatives sometimes referred to as smart 

growth. In particular, EPA has (1) information networks, Web sites, 

guidance on best practices, and training programs for local officials, 

among other things and (2) is issuing guidance on ways to calculate the 

potential emissions reductions from alternative land uses, such as 

redeveloping old industrial sites in an urban area rather than building 

on a new site in the suburbs, in order to discourage and reduce sprawl 

and reduce vehicle miles.



While these efforts have met with success, the available resources and 

scope of impact has been limited. For example, EPA has been able to 

award Clean Air Transportation Communities grants to only 10 state, 

local, or tribal governments, for a total of about $1.27 million to 

date, but has discontinued funding for fiscal year 2002 because of 

budget constraints. In addition, efforts to improve travel models are 

not focused on creating models that fully integrate transportation, the 

environment, and land use, which would help planners consider the 

effects that their transportation decision will have on land use, 

future growth, and air quality. Furthermore, at the time of our survey, 

few planners were aware of EPAs guidance on how to obtain credit in 

their emissions budgets for reductions from alternative land uses, and 

EPA had conducted only a limited number of workshops and did not plan 

to offer additional training. We also found that the level of support 

across EPAs regions for these types of initiatives varied and that 

unless EPA better coordinated its efforts through a more comprehensive 

strategic plan, it would not be able to effectively leverage its 

resources and achieve more widespread results. We recommended that EPA 

devise such a strategy, and the agency expects to have this completed 

by the fall of this year.



Planners Identified Additional Ways the Federal Government Could Help 

Them Further Limit Transportations Impacts on Air Quality:



The planners responding to our survey identified the following actions 

the Congress and the federal government could take to remove some of 

the barriers to assessing and limiting the adverse impacts of land use 

on air quality.



Financial incentives. Federal funding could be allocated to help 

promote a more collaborative working relationship among transportation, 

environmental, and land use planners so that they can develop ways to 

improve air quality. For example, federal funding could be targeted 

more to those transportation projects that were designed through a 

collaborative effort.



Technical assistance. Federal agencies could provide additional tools 

to promote greater consideration of how transportation, air quality, 

and land use interact, including (1) access to technical staff, (2) 

examples of communities or regions that successfully demonstrated how 

changes in land use have affected vehicle miles traveled, and (3) 

improved models, such as those that can measure the emissions of small 

projects, like bicycle and pedestrian facilities.



Public outreach. Federal agencies could undertake additional efforts to 

educate the public and local officials on how their land use and 

transportation decisions affect air quality, which could help to 

promote collaboration among all of these partied on ways to limit these 

effects.



Conclusions:



Using the federal clean air and transportation laws, the nation has 

significantly reduced harmful vehicle emissions, thereby helping to 

protect public health and the environment. Technological advances will 

also continue to produce cleaner vehicles and fuels, further reducing 

harmful emissions. But for some communities, these advances may not be 

enough to compensate for rapid growth and the associated growth in 

miles driven. These communities may still need help to guide their 

growth and design their future transportation systems to limit 

pollution. However, the current clean air and surface transportation 

requirements and programs do not directly encourage communities to 

consider more innovative transportation projects or alternative land 

development strategies as a means to reduce emissions. Nor do they 

encourage communities to take action that will preserve the clean air 

that they still enjoy.



With the upcoming reauthorization of surface transportation programs, 

the Congress has an opportunity to strengthen its past efforts and 

create new initiatives to promote transportation and growth that 

protects public health and the environment. We would like to bring to 

your attention to, as well as reaffirm, a number of recommendations we 

made in our 2001 report to help transportation planners and communities 

in assessing, preventing, or limiting harmful vehicle emissions. These 

recommendations included the following:



The Secretary of Transportation should request all transportation 

planners to assess the emissions impacts of their proposals and use the 

results of these assessments to help educate local decisionmakers about 

the consequences of their transportation and land use decisions. This 

would encourage all parties to collaborate and take a broader, more 

regional approach to solving air quality concerns.



The Administrator, EPA, should target available financial incentives in 

ways that encourage transportation planners, environmental officials, 

and local decisionmakers to collaboratively consider the impacts of 

transportation and land use on air quality.



Both the Secretary and Administrator should provide more access to 

technical tools, such as staff and user-friendly models that integrate 

transportation, environmental protection, and land use, and better 

market these tools to transportation and local decisionmakers.



The Administrator, EPA, should take more action to educate the public 

and local decisionmakers about the air quality impacts of their 

transportation and land use choices.



Our report also suggested ways that the Congress, as it reauthorizes 

the surface transportation laws, could help assist those states and 

localities that want to limit the air quality impacts of their land use 

and transportation decisions by:



adding the requirement that planners consider the environmental impacts 

of different land use strategies as a step in the transportation 

planning process;



continuing but modifying funding programs designed to link 

transportation and air quality so that they also take into 

consideration alternative land uses, where appropriate, or create new 

programs to make this link;



providing funding to states and localities, when possible, to help them 

obtain technical expertise, data, and analyses to assess land use 

impacts and mitigate adverse effects; and:



providing federal agencies with greater discretion over a portion of 

their transportation or environmental funds to encourage assessment and 

mitigation of land use impacts on the environment.



Contacts and Acknowledgments:



For further information, please contact John Stephenson at (202) 512-

6225. Individuals making key contributions to this testimony include 

Eileen Larence, Elizabeth Erdmann, and Cindy Steinfink.



FOOTNOTES



[1] U.S. General Accounting Office, Environmental Protection: Federal 

Incentives Could Help Promote Land Use that Protects Air and Water 

Quality, GAO/02-12 (Washington, D.C.: October 31, 2001). 







[2] The Transportation Equity Act for the 21ST Century (TEA-21), the 

successor to the Intermodal Surface Transportation Efficiency Act of 

1991 (ISTEA), is due to be reauthorized in 2003. 



[3] U.S. Environmental Protection Agency, Office of Air Quality 

Planning and Standards, National Air Quality Emissions Trends Report, 

1999 (Washington, D.C.: March 2001).



[4] National Research Council, Transportation Research Board, Surface 

Transportation Environmental Research: A Long-Term Strategy 

(Washington, D.C.: 2002).







[5] See Wayne T. Davis, Terry L. Miller, Gregory D. Reed, Prakash 

Doraiswamy, Anna Tang, and Pedro Sanhueza, VMT Growth Rates in the 

U.S. and Their Effects on NOx and VOC Emissions (Proceedings of the 

94TH Annual Conference of the Air and Waste Management Association 

(Orlando, Florida: June 25-27, 2001).







[6] The limits have been upheld by the courts, but the United States 

Supreme Court has found EPAs ozone National Ambient Air Quality 

Standard implementation policy to be unlawful and has instructed EPA to 

develop a plan consistent with the Courts opinion. Whitman v. American 

Trucking Assns, Inc., 531 U.S. 457 (2001); on remand sub nom. American 

Trucking Assns, Inc. v. EPA, 283 F.3d 355 (D.C. Cir. 2002).







[7] EPAs estimate is based on 8-hour monitoring during 1997 through 

1999; these data will change from year to year, and the most current 

data will be used to make final designations of ozone nonattainment 

areas when the standard is implemented. The data on the 1-hour ozone 

areas are as of January 29, 2001.







[8] Areas that exceed the standards--nonattainment areas--or are 

maintaining the standards after prior violations--maintenance areas-

-for ozone, carbon monoxide, particulate matter, and nitrogen dioxide 

are subject to the conformity requirement. 







[9] Projects related to highway safety, transportation control measures 

included in an approved state implementation plan, or transportation 

projects approved or funded by the federal government can move forward.







[10] Funds are distributed to states according to a formula based on 

attainment status for ozone and carbon monoxide and the population 

living in the affected area. States without air quality problems 

receive a minimum amount of funds and can spend some of them on 

projects not prescribed under the program.