Environmental Protection
The Federal Government Could Help Communities Better Plan for Transportation That Protects Air Quality Gao ID: GAO-02-988T July 30, 2002Despite regulations limiting emissions and improved vehicle and fuel technologies, the air in many cities and towns still does not meet air quality standards. Vehicle emissions contain substances, including carbon monoxide, nitrogen oxides, and volatile organic compounds, that degrade air quality and threaten public health and the environment. Vehicles emissions account for about one third to one-half of these pollutants. Epidemiological and other studies have consistently found that breathing emissions containing these compounds contributes to respiratory and other health problems. Vehicle emissions also harm vegetation and cause crop damage. Provisions in the clean air and surface transportation laws have encouraged transportation planners to look for ways to curb harmful emissions, but predominantly in areas that already suffer pollution problems. The Clean Air Act requires planners to demonstrate that their plans and programs will not worsen air quality, but only in areas with current or prior air quality problems. Congress and federal agencies have opportunities to provide more help to transportation planners and communities considering the environmental impacts of their transportation and land use decisions.
GAO-02-988T, Environmental Protection: The Federal Government Could Help 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 community‘s 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 nation‘s 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 conformity‘s 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 transportation‘s 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 nation‘s 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 nation‘s
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
organization‘s 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
organization‘s 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 area‘s 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 area‘s 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 chairman‘s request,
we are initiating a more comprehensive review of the conformity
requirement‘s 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
EPA‘s new limits on ozone and fine particulate matter will increase the
number of communities with air quality problems and may increase demand
for the program‘s 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 agency‘s 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 EPA‘s 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 EPA‘s 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 Transportation‘s 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 EPA‘s ozone National Ambient Air Quality
Standard implementation policy to be unlawful and has instructed EPA to
develop a plan consistent with the Court‘s opinion. Whitman v. American
Trucking Ass‘ns, Inc., 531 U.S. 457 (2001); on remand sub nom. American
Trucking Ass‘ns, Inc. v. EPA, 283 F.3d 355 (D.C. Cir. 2002).
[7] EPA‘s 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.
