Linking Transportation and Air Quality 

Planning: 

Implementation of the Transportation 

Conformity Regulations in 15 

Nonattainment Areas
U.S. Environmental Protection Agency

and the 

Federal Highway Administration,

U.S. Departrment of Transportation

Linking Transportation and Air Quality 

Planning: 

Implementation of the Transportation 

Conformity Regulations in 15 

Nonattainment Areas

EPA-420-R-99-011

March 1999
U.S. Environmental Protection Agency Publication # EPA420-R-99-011

Arnold M. Howitt and Elizabeth M. Moore

Taubman Center for State and Local Government

John F. Kennedy School of Government

Harvard University

March 1999

A Report to the

U.S. Environmental Protection Agency

and the

Federal Highway Administration,

U.S. Department of Transportation

LINKING TRANSPORTATION AND 

AIR QUALITY PLANNING:

IMPLEMENTATION OF THE 

TRANSPORTATION CONFORMITY REGULATIONS 

IN 15 NONATTAINMENT AREAS 
iii

ACKNOWLEDGMENTS

It is a genuine pleasure to thank the many people who have made this research possible. We

owe our most important debt of gratitude to the more than 230 individuals – identified by name in

an appendix to this report – who were interviewed and provided other data about the transportation

conformity process. Their knowledge and insight are reflected on virtually every page that follows.

Without the cooperation, patience, and candor of all of these people – sometimes provided on

multiple occasions – this study quite literally could not have been carried out.

From the outset, the researchers were promised full intellectual independence by the federal

agency sponsors, EPA and FHWA. That independence has been scrupulously respected by the

federal agency staff with whom we have worked closely throughout this project. Particular assistance,

for which we are extremely grateful, was provided by Laura Voss, Meg Patulski, Kathryn Sargeant,

and Margo Oge of the Environmental Protection Agency, and Lucy Garliauskas and James Shrouds

of the Federal Highway Administration.

At Harvard, our efforts have been ably supported by Treina Fabre, Sophie Delano, and James

Scafide, who served at various points as research assistants, and by Rochelle Furman, Kate

Fitzpatrick, and Julie Zanotti, who transcribed numerous interview tapes. Sandra Garron effectively

managed project finances, and Julie Zanotti deftly performed many other administrative tasks that

kept the project moving. On several occasions, Stephanie Abundo and Todd Olmstead took time out

from their Ph.D. research to provide helpful technical assistance.

Joshua Anderson was a partner with one of the authors in conducting an earlier study of implementation of the transportation provisions of the Clean Air Act Amendments of 1990. The current

work has benefitted significantly from his earlier efforts.

The people at the Taubman Center for State and Local Government are genuinely delightful

companions, supportive colleagues, and thoughtful commentators. Alan Altshuler, David Luberoff,

Mary Graham, and Jay Walder, in addition to those mentioned above, deserve special thanks for their

support, but others too numerous to mention by name are responsible for creating a unique and

stimulating environment.

The authors of this study are solely responsible for the accuracy of the data presented here and

for the generalizations and conclusions they have reached. They have benefitted greatly, however, from

the careful review and scrutiny of all or parts of this manuscript by representatives of the federal agencies

and some of their interview respondents. The authors are extremely grateful to these commentators, who

have saved them from errors of omission and commission, while helping them refine their interpretations

of the data. Any shortcomings that remain, however, are the exclusive responsibility of the authors.

Neither the project’s federal sponsors nor Harvard University necessarily agree with or endorse the

findings and conclusions presented here. Those are ours alone.

Arnold M. Howitt and Elizabeth M. Moore

March 1999
v

TABLE OF CONTENTS

Acknowledgements ..................................................... iii

Table of Contents ........................................................ v

Executive Summary .................................................... ix

Chapter 1: The Conformity Assessment Project ........................... 1

Project Purposes ...................................................... 1

Focal Questions ....................................................... 2

Selection of the Research Sites ............................................ 3

Research Methods and Data .............................................. 8

The Research in Perspective .............................................. 9

Outline of the Report .................................................. 10

Chapter 2: The Purposes and Requirements of Transportation 

Conformity ....................................................... 12

Policy Antecedents .................................................... 12

Purposes and Expectations .............................................. 14

Pollution Reduction and Public Health ............................... 14

A Procedural Framework and Incentives .............................. 14

Improving the Planning Process .................................... 15

Public Deliberation and Decision Making ............................. 16

Advancing the Environmental Advocacy Agenda ....................... 16

Conformity Requirements .............................................. 17

The 1991 Interim Conformity Guidance .............................. 18

The 1993 Conformity Rule ........................................ 19

Performance Standards ........................................... 20

Procedural Requirements ......................................... 21

Penalties and Penalty Triggers ..................................... 22

Amendments to the 1993 Conformity Rule .................................. 24

The August 1995 Amendments ..................................... 24

National Highway System Designation Act of 1995 ..................... 25

The November 1995 Amendments .................................. 25

The August 1997 Amendments ..................................... 27

Chapter 3: Implementing the Transportation Conformity Requirements . . 28

Passing the Emissions Tests ............................................. 30

Budget Test ................................................... 30

Build/No-Build Test ............................................. 36

Less-than-1990 Test ............................................. 37
vi

Using the Required Modeling Techniques .................................. 37

Demonstrating Timely Implementation of SIP TCMs .......................... 38

Meeting the Fiscal Constraint Requirement ................................. 38

Links to SIP Failures .................................................. 39

Human Error ........................................................ 40

Chapter 4: Institutional Roles in the Transportation 

Conformity Process ............................................... 41

Building Institutional Capacity ........................................... 44

Contextual Conditions ........................................... 44

Organizing for Conformity ........................................ 46

Developing Technical Capacity ..................................... 49

Establishing Interagency Consultation Procedures ............................ 52

Start-up Issues ................................................. 52

Formalizing Consultation Procedures in a Conformity SIP ................ 53

Interagency Consultation in Practice ................................. 56

Stakeholder Participation in Conformity .................................... 64

Environmental Advocates ......................................... 65

Business Associations ............................................ 68

The Broader Visibility of Conformity ...................................... 69

Engaging Policy Makers .......................................... 69

Public Visibility ................................................ 71

Chapter 5: Conformity Effects on Transportation and Air Quality Plans ... 73

Effects of Conformity on Transportation Plans and Programs .................... 73

Effects on Highway Projects ....................................... 74

Effects on Transit, Other TCMs, and Land Use Planning ................. 80

Conformity and Air Quality Planning ...................................... 86

1992 CO and PM10 SIPs .......................................... 86

1993 VOC Reduction SIPs ........................................ 87

Effects on Subsequent SIP Planning ................................. 89

Conformity Effects on SIP TCMs ................................... 92

Other SIP Impacts .............................................. 93

Chapter 6: Toward A New Planning “Arena” ............................. 96

Better Data and Analytic Tools .......................................... 96

Analysis and the Regulatory Process ...................................... 97

Confronting Conformity Difficulties ....................................... 99

Re-examining the Models ........................................ 100

Generating Policy Debate ........................................ 100

Institutional Dynamics of Changing Transportation and Air Quality Plans .... 101

Conformity as an Evolving Process ...................................... 103
Appendix I: Glossary of Abbreviations ................................. 104

Appendix II: Conformity Profiles of 15 Study Sites ...................... 106

Atlanta ............................................................ 106

Baltimore .......................................................... 108

Boston ............................................................ 109

Charlotte .......................................................... 111

Chicago ........................................................... 113

Denver ............................................................ 114

Houston ........................................................... 116

Milwaukee ......................................................... 117

Northern New Jersey ................................................. 118

New York ......................................................... 119

Philadelphia ........................................................ 120

Phoenix ........................................................... 121

Portland ........................................................... 122

Salt Lake City ...................................................... 123

San Francisco ....................................................... 124

Appendix III: Interview Subjects by Study Site .......................... 125

Atlanta ............................................................ 125

Baltimore .......................................................... 126

Boston ............................................................ 126

Charlotte .......................................................... 127

Chicago ........................................................... 128

Denver ............................................................ 129

Houston ........................................................... 130

Milwaukee ......................................................... 131

Northern New Jersey ................................................. 132

New York ......................................................... 133

Philadelphia ........................................................ 134

Phoenix ........................................................... 135

Portland ........................................................... 136

Salt Lake City ...................................................... 137

San Francisco ....................................................... 137

National ........................................................... 139

Appendix IV: Sources of Population and Transportation Data .......... 140

Appendix V: Report Authors ........................................... 143

*****

Figures and Tables

Figure 1-1: Nonattainment Areas in the Study ................................ 4

Table 1-1: Growth Rates of Population and Vehicle Miles Traveled by Study Site ..... 6
viii

Table 1-2: Nonattainment Classifications for Study Sites by Pollutant ............... 7

Table 3-1: Types of Conformity Problems by Nonattainment Area ................ 29

Table 3-2: Problems Meeting the Conformity Requirements by 

Nonattainment Area .......................................... 31-32

Table 4-1: Core Public Agencies in Transportation and Air Quality by 

Nonattainment Area .......................................... 42-43

Table 5-1: Population and VMT Growth Rates by Higher- and Lower-Growth

Study Sites .................................................... 76
Arnold M. Howitt and Elizabeth M. Moore

Taubman Center for State and Local Government

John F. Kennedy School of Government

Harvard University

March 1999

CHAPTER 1: THE CONFORMITY ASSESSMENT PROJECT

The Clean Air Act Amendments (CAAA) of 1990 require far-reaching efforts under the

“transportation conformity” regulations to assure that transportation investments in nonattainment

and maintenance areas are consistent with state commitments to meet national air pollution standards.

 This research documents how these regulations were implemented during the period 1991 through

January 1998.

Focal Questions. Three questions have organized the study: 

• How has conformity affected key agencies and constituencies’ organizational capacity and

relationships? 

• How has conformity changed the transportation planning/programming process and its

results? 

• How has conformity changed air quality planning and regulation? 

Although the research does not attempt to evaluate the technical dimension of conformity

modeling, it seeks to place the technical process in the larger context of the institutional relationships

involved.

Study Sites. The researchers chose a non-random sample of 15 nonattainment areas –

Atlanta, Baltimore, Boston, Charlotte, Chicago, Denver, Houston, Milwaukee, New York, Northern

New Jersey, Philadelphia, Phoenix, Portland, Salt Lake City, and San Francisco – to concentrate on

large metropolitan areas with more severe air pollution problems. The sample does not include rural

nonattainment areas, small metropolitan areas, or areas with minimal pollution problems.

In each area, the researchers consulted documents and publications and conducted personal

interviews. In all, they spoke with more than 230 individuals knowledgeable about conformity, including representatives from MPOs, state air agencies, state DOTs, EPA and FHWA field offices,

environmental advocacy groups, and other stakeholders.

Executive Summary

LINKING TRANSPORTATION AND AIR QUALITY PLANNING:

IMPLEMENTATION OF THE TRANSPORTATION CONFORMITY

REGULATIONS IN 15 NONATTAINMENT AREAS
 Executive Summary: Linking Transportation and Air Quality Planning x

CHAPTER 2: THE PURPOSES AND REQUIREMENTS OF TRANSPORTATION

CONFORMITY

The conformity process is intended to ensure that a nonattainment (or maintenance) area will

keep transportation-related emissions within the bounds needed to bring the state into compliance

with (or maintain) the national ambient air quality standards – and thus to advance the public health

goals of the Clean Air Act. But the statute and the regulations promulgated by EPA to implement

them imply a broader set of purposes, and stakeholder groups have layered on additional expectations

about how conformity would work. These extended purposes and expectations include: 

• establishment of a procedural framework and incentives for analyzing transportation-related pollution, 

• improvements in both transportation and air planning processes and establishment of

tighter connections between them, 

• improvements in public deliberation and decisions on transportation and air quality issues,

and 

• promotion of elements of the environmental advocacy agenda.

CHAPTER 3: IMPLEMENTING THE TRANSPORTATION CONFORMITY REQUIREMENTS

During the study period, each of the 15 study sites experienced at least some difficulty with

the technical and procedural requirements of the 1993 transportation conformity regulations. These

problems are considered in six categories: (1) Emission tests: passing the emission budget and

build/no-build tests, (2) Modeling procedures: fulfilling the transportation modeling requirements, (3)

TCM implementation: demonstrating timely implementation of those transportation control

measures committed to in control strategy SIPs and maintenance plans, (4) Fiscal constraint:

showing that the transportation plan meets the ISTEA fiscal constraint requirement, (5) SIP failure:

triggering conformity problems because of problems with SIP submissions, and (6) Human error:

experiencing conformity problems because of procedural confusion and/or data analysis mistakes.

The nature and consequences of these problems for the transportation planning process and

air quality regulation varied significantly. (See Table 3-2 in the body of the report for the problems

encountered by each nonattainment area.) In applying the specific emission tests of the 1993 regulations, five study sites encountered significant difficulties with the budget tests, which continued to

pose serious problems for Atlanta, Charlotte, and Houston at the end of the study period in January

1998. The build/no-build test was problematic for even more areas, but the difficulties were less

severe – and, because this requirement was substantially altered by the 1997 conformity amendments,

the problem has become moot in most areas. No study area reported difficulty with the less-than1990 test.

The other conformity requirements were generally less problematic than the emission tests.

While a number of study sites had some difficulties gearing up for the network modeling requirements

of the 1993 regulations, only New York City and Chicago faced serious conformity delays as a result.
 Executive Summary: Linking Transportation and Air Quality Planning xi

The fiscal constraint requirement posed no serious problems for any areas, although Boston

experienced a brief conformity delay because of this test. Initially, the provisions of the 1993 rule

regarding SIP failures caused problems for a few areas; but the 1995 conformity amendments

alleviated this issue. During the study period, only Salt Lake City suffered a conformity freeze or

lapse because of SIP failure.

CHAPTER 4:INSTITUTIONAL ROLES IN THE TRANSPORTATION CONFORMITYPROCESS

Fulfilling the purposes of conformity depends crucially on creating stronger institutional links

between two sets of agencies – transportation and air quality – that operated quite independently of

each other prior to enactment of the CAAA of 1990. 

Contextual Conditions. For the core regional and state agencies involved in conformity

– particularly MPOs, state and regional air agencies, and state DOTs – implementation of the

conformity regulations created significant stresses, not merely in terms of what conformity itself

required but also in the context of broader changes stemming from the CAAA and ISTEA. Even

without the conformity requirements, air quality and transportation agencies faced substantial increases in workload as well as the need to develop new skills and to build relationships with other

agencies.

Developing Technical Capacity. Conformity made significant start-up demands on

MPO technical capacity and resources. Of the 15 study sites, New York City and Chicago had the

most difficult experiences. Most of the MPOs in the study were subject to the network modeling

requirements of the 1993 conformity regulations, and all needed to upgrade their modeling capabilities to meet the general requirements of conformity. Typically, MPOs had to hire additional inhouse technical staff and/or consultants for this purpose. While conformity was often the decisive

factor, these upgrades were also motivated by ISTEA’s planning requirements and the provision of

federal funds to strengthen planning capabilities. 

For state air agencies developing necessary technical resources was also challenging. To meet

a spate of new responsibilities under the Clean Air Act, including conformity, most air agencies hired

additional staff members who had or could develop transportation expertise, but this took time; and

new staff had to be assimilated to new institutional practices and cultures. By contrast with both air

agencies and MPOs, state DOTs faced far less conformity-related pressure for technical capacity

enhancement.

Both the U.S. Environmental Protection Agency and the U.S. Department of Transportation

significantly contributed to the development of organizational capacity for conformity by providing

technical assistance to state and regional agencies.

Establishing Interagency Consultation Procedures. The conformity regulations emphasized the need for effective interagency consultation at each stage of the conformity process.

Consultation practices have emerged gradually as first the 1991 interim conformity guidelines and

then the 1993 regulations have been implemented. 

As a result of start-up challenges, many areas missed the window of opportunity for consultation that could have informed the first set of SIPs in the CAAA/ISTEA era. In a few areas, such

as Boston, Houston, and Milwaukee, broad-based SIP planning task forces were established.
 Executive Summary: Linking Transportation and Air Quality Planning xii

However, transportation planners in some other areas were not sufficiently aware of the importance

of their involvement in SIP planning. Thus, emission budgets were derived implicitly from SIP inventories without enough consideration of their implications for future conformity determinations. Likewise, during the start-up phase, air planners were just beginning to establish their role in transportation planning and frequently felt that they had too little influence on the first post-ISTEA round of

transportation plans and TIPs.

Typically led by the air agency, concerned agencies in most states began working on conformity SIPs in 1994. Many states finished work essentially within the allotted year, building on the

experience gained in their initial conformity experiences. Most developed interagency consultation

procedures with little disagreement, and a number regarded the exercise of specifying responsibilities

and defining processes as quite useful in clarifying expectations about how conformity would be

carried out. To accommodate forthcoming amendments to the conformity regulation, however, EPA

moved the deadline for completed conformity SIPs into 1998. Conformity SIPs were therefore not

complete in many areas at the conclusion of the study period in January 1998.

Consultation in Practice. Whatever the legal status of their conformity SIPs, though, the

study areas have developed interagency consultation practices that go well beyond previous levels

of interaction. Formal consultation goes beyond the mechanics of conformity in most, but not all, areas. Air agencies now typically participate in some fashion on the MPO committees where transportation decisions are made, so they have an opportunity to make suggestions or raise issues at a

formative stage of policy development. Official interactions, however, tell only part of the story of

interagency consultation. Formal consultation procedures have frequently helped to foster stronger

informal working relationships and deeper understanding of the issues in a number of areas.

Many of the state and regional officials interviewed for the study stressed that, as a result of

the formal and informal relationships that conformity has spurred, they have developed a much greater understanding of their counterparts’ challenges and the constraints that shape their policy approaches. This makes it far easier to acknowledge problems and work together to solve them. Consultative relationships, once initiated, therefore tend to become reinforcing.

In some areas, however, consultation is relatively limited and focused to a great degree on formal interactions such as committee meetings, review of proposed conformity determinations by air

quality planners, and comments by transportation planners on proposed SIP budgets or mobile source

control measures.

Even in areas where strong consultative relationships have developed, important limitations

remain. Where close interagency relationships develop, they do not transcend or submerge distinct

institutional interests and perspectives in conformity. Nor do they fundamentally change disparities

of bureaucratic or political power. Agency personnel continue to represent their own agencies and

may not always be able to find common ground with their colleagues on specific matters. As a result,

while state air agencies provide important technical inputs to conformity analysis in a number of study

sites, they have generally been reactive rather than proactive participants in conformity. Resource

limitations and the opportunity costs of using this scarce capacity for conformity are a major barrier.

Because a number of air agencies have little in-house technical expertise on transportation demand

modeling, they are uncomfortable probing that dimension of conformity even when they have serious

reservations about how the MPO is handling it. Perceived political weakness of air agencies relative
 Executive Summary: Linking Transportation and Air Quality Planning xiii

to transportation counterparts is another barrier. In only a few instances identified in the study sites

have air agencies been aligned against transportation agency positions in major conformity disputes.

Federal Agency Roles. The conformity regulations give DOT the final authority to decide whether an MPO’s conformity determination should be approved. In practice, FHWA has taken

the lead in this review, working closely with EPA and FTA. The federal agencies also consider comments from interested stakeholders (most often environmental advocacy groups). Serious objections

from a key stakeholder typically trigger intensive review of the MPO’s conformity analysis. 

FHWA has generally worked with FTA and EPA to reach consensus on a federal position,

sometimes managing discussions at multiple levels of the agencies. In only one instance in the study

sites – Atlanta – has there been severe disagreement between DOT and EPA.

In each state in the study, FHWA has division offices in the same city in which the state DOT

headquarters is located. Therefore, its air quality staff members generally have direct access to their

counterparts in state and regional agencies and often provide technical assistance and advice.

EPA field staff, operating from only ten regional offices, do not have comparable access in

many instances. They have nonetheless played active roles in implementing conformity – providing

technical assistance, troubleshooting on major issues, advising and consulting with national

headquarters staff, working with states and MPOs to develop conformity SIPs, and dealing with the

conformity consequences of control strategy SIP revisions or disapprovals. However, EPA’s involvement in conformity at the MPO/nonattainment area level has been significantly more variable, and

weaker overall, than FHWA’s – to a great degree because EPA lacks a state-level presence equivalent

to FHWA’s divisions. 

FTA also has only regional offices, and its conformity role has generally been less extensive

than either FHWA or EPA’s.

At the headquarters level, FHWA staff in Washington provide technical backup, interpret

agency policy, promote inter-area consistency, and manage liaison with EPA headquarters staff.

EPA’s mobile source headquarters staff, primarily based in Ann Arbor, Michigan, played the lead role

in drafting the transportation conformity regulations and the subsequent amendments (in close consultation with DOT, whose concurrence was required by the statute). EPA headquarters has also

played a continuing role in interpreting the regulations, coordinating regional office mobile source

specialists to ensure national consistency, and has communicated regularly with state and regional

transportation and environmental agencies and other stakeholder groups.

Stakeholder Roles. The conformity regulations require both that the public have

opportunity to comment on conformity analyses before the determination is made and that MPOs

fulfill the requirements of the DOT metropolitan planning regulations, which more generally mandate

public participation in transportation planning. Using these paths of access, environmental advocacy

groups have been the most active non-governmental stakeholders in conformity, playing key roles in

about one third of the 15 study sites and a more limited role in most others. To track conformity

well, however, is time-intensive and requires significant technical skills. To participate effectively,

therefore, environmental advocates have had to make efforts that, in many respects, parallel the
 Executive Summary: Linking Transportation and Air Quality Planning xiv

involvement of personnel from the core public agencies. In several study sites, strong environmental

groups that have focused on transportation issues more generally have therefore strategically chosen

not to become actively involved in the conformity process. And not every study site has advocacy

groups capable of effective participation.

Business associations are the only other stakeholder group active in conformity – and then

only in a few nonattainment areas.

The Broader Visibility of Conformity. At least up to the conclusion of the study period

– January 1998 – conformity had not generally been effective in focusing the attention of high-level

appointed policy makers and elected officials on the issues of transportation and air quality. The

complex and highly technical nature of the conformity process has been a barrier to expanding participation in the planning arena beyond the core group of planning and policy officials who deal with

it on a regular basis. 

The core public agencies have also had limited success in drawing the general public’s attention to conformity. In most of the study sites, there is scant media coverage of the transportation

planning process in general and conformity in particular. Unless controversy arises, conformity is an

inherently difficult subject for newspapers, let alone television or radio, to report. Its highly technical

nature, revolving around complex regulatory requirements and arcane modeling procedures, diminishes its accessibility to both generalist reporters and the public.

To the extent that the core agencies have attracted public attention to conformity, they have

relied primarily on organizing and formally announcing public meetings, placing notices in their newsletters, and – increasingly – posting notices and technical documents on MPO websites. Consequently, very few unaffiliated citizens have availed themselves of opportunities for involvement, even

when MPOs and others have exerted considerable effort to secure participation.

However, in several areas that have experienced long conformity lapses (such as Denver,

Charlotte, and Atlanta) the level of media coverage has increased, including newspaper coverage that

explains the policy issues as well as describes the conflict. This makes the issues more accessible to

the public. Under these circumstances, moreover, senior policy makers and elected officials are also

more likely to become active in trying to resolve the conformity problems.

CHAPTER 5: CONFORMITY EFFECTS ON TRANSPORTATION AND AIR QUALITY PLANS

Effects on Transportation Plans and Programs. Firm conclusions about impacts of

conformity on transportation plans/programs are premature because of the dynamics of transportation

planning and project development. The regulations were not in effect during the formative years of

many of the projects in transportation plans/programs that were subject to conformity during the

study. In effect, the conformity regulations were applied to the final stages of planning. It is not surprising, therefore, that the effects of conformity have been felt more clearly in the planning process than

in the substance of the plans themselves.

During the period in 1991-1993 that the interim conformity guidance was in effect there was

considerable initial uncertainty about what this unfamiliar procedure entailed and how it had to be

documented, but most MPOs experienced relatively little difficulty demonstrating conformity against

this standard. 
 Executive Summary: Linking Transportation and Air Quality Planning xv

HIGHWAYPROJECTS IN HIGH-GROWTH AREAS. Under the 1993 regulations, as amended, conformity’s impacts on highway projects have been felt primarily in a number of the high-growth areas

in the study – Atlanta, Charlotte, Denver, Houston, Salt Lake City – which found passing

conformity’s emission budget tests problematic during the study period. 

Except for Portland, the high-growth study areas tend to have substantial dispersed land development and a significantly rising level of vehicle-miles traveled (VMT). As a consequence, they

typically have major highway capacity expansion plans. These areas generally have transit systems

with much smaller mode shares than the typical low growth area in the study – and their growth is

primarily occurring at the peripheries of the metropolitan area where providing high-quality transit

service is problematic. On the air quality side, because these areas, with the exception of Houston,

have less severe ozone problems than the low growth areas in the study, they have earlier attainment

deadlines. Consequently, they must show required reductions, net of VMT growth, more rapidly than

the lower-growth areas.

The effects of the difficulties that Atlanta, Charlotte, Denver, Houston, Salt Lake City had

in passing conformity emission budget tests ranged from delays in proceeding with certain planned

projects, to scaling back the design scope of others, to eliminating certain projects from proposed

transportation programs. Atlanta and Charlotte were experiencing conformity lapses at the time the

study concluded in January 1998.

HIGHWAYPROJECTS IN LOWER-GROWTHAREAS. Implementation of the conformity rule has had

far less impact on transportation plans/programs in the older, relatively low growth metropolitan areas

in the study – Chicago, New York, Baltimore, Boston, Philadelphia, Milwaukee, northern New Jersey, and San Francisco. Although these areas typically have more serious pollution problems, they

generally have mature highway infrastructure networks, well established transit systems, and relatively

slow VMT growth. As a result, many projects in their transportation plans/programs have neutral

or positive air quality benefits. These projects include reconstruction and maintenance of the roadway

system and most investments in transit. Thus, conformity has not required major adaptations of transportation plans in these areas because there are few major capacity expansions on the table, the mix

of projects already includes many with air quality benefits, and technology measures are being

adopted in the SIP. 

These areas, however, have not yet met their stiffest conformity challenges. In the absence

of attainment demonstrations for these areas, the emissions budgets that they have met come from

15% VOC reduction SIPs and subsequent RFP SIPs. Moreover, at the end of the study period, some

had not yet determined conformity against 1999 RFP levels.

ONGOING HIGHWAY IMPACTS. How Charlotte and Atlanta would resolve the lapse problems

noted above was not clear at the conclusion of the study period in January 1998. What these

situations and other less dramatic cases in the study suggest, however, is how difficult institutionally

and politically it is for MPOs and state DOTs to make changes in their transportation plans and

programs. Given the difficulty of extricating projects from plans, and the length of time that will

elapse before projects in the pre-ISTEA pipeline are exhausted, it is not surprising that major changes

in the contents of regional transportation plans have been few. 

As a result of conformity, though, it appears that proposals for major highway capacity enhancement, while not precluded, are less likely to move into preliminary planning phases than they
 Executive Summary: Linking Transportation and Air Quality Planning xvi

might have previously, if they seem likely to be “emission budget busters.” Because major highway

projects may threaten financial as well as emission budgets, moreover, this effect is strongly reinforced by the fiscal constraint requirement of ISTEA.

EFFECTS ON TRANSIT, OTHER TCMS, AND LAND-USE PLANNING. Because a number of conformity stakeholders, particularly environmental advocacy groups, expected that conformity would

promote specific elements of their transportation policy agendas, this study has investigated whether

conformity has had an impact on transit, other transportation control measures (TCMs), and land-use

planning.

In the 15 study sites, conformity considerations seem to have reinforced – but not determined

– transit policies in two areas (Denver and Portland). At the end of the study period in January 1998,

however, transit planning in the others had been much less affected by conformity. Contrary to the

cited expectations, most rapidly growing metropolitan areas in the study, including those that have

experienced conformity difficulties, had not found transit’s emission benefits sufficient grounds to

encourage major investments. However, the areas that already have extensive transit networks have

found the emission benefits of continued investment helpful in demonstrating conformity.

Only two areas (Boston and Baltimore) reported adopting a TCM specifically for conformity

purposes. In others, the availability of CMAQ funding has probably increased the attractiveness of

some TCMs relative to other possible expenditures; and several areas routinely used an off-model

analysis of TCMs to pass the build/no-build test. Because most TCMs show only modest air quality

benefits, however, other factors have driven their inclusion in area plans; they have not been programmed specifically to capture air quality benefits.

Some proponents of conformity hoped that modeling transportation/land use links would also

lead to consideration of alternative land-use scenarios in the planning process and wider acceptance

of land-use regulation as a viable policy option for reducing mobile source emissions. However, with

the exception of Portland among the 15 study sites, the impact of conformity on actual land-use decision making has been limited by the distribution of institutional responsibilities and the politics of

land use regulation.

Conformity and Air Quality Planning. During the start-up phase of CAAA/ISTEA implementation, conformity did not have a large influence on the first rounds of SIP planning, primarily

because of competing statutory demands and the timing of the 1993 regulations. 

As areas have moved through subsequent rounds of air quality and transportation planning,

however, conformity has had more impact. In the face of conformity problems, some areas have adjusted or amended mobile source budgets. Other areas have proactively reassessed emission budgets

to anticipate and deal with looming conformity problems. For example, to deal with PM10 conformity

problems in 1994, the Denver region established out-year budgets that increased over time, while it

mitigated emissions in the downtown area to keep them within allowable limits. In 1995, Salt Lake

City added ten years to its ozone maintenance plan, matching the time frame of its transportation plan,

to ease problems of passing the NOx budget test for ozone. Portland proactively established out-year

emission budgets in its 1996 ozone maintenance plan to make future conformity determinations less

difficult.
 Executive Summary: Linking Transportation and Air Quality Planning xvii

Just as air planners have become more significant and involved stakeholders in transportation

planning, transportation planners have become more active stakeholders in air planning. In most

ozone nonattainment areas, they have been much more involved with the 9% and attainment year

budgets than they were with the 15% VOC reduction SIPs, although in several areas (e.g., Atlanta,

Philadelphia, and New York City) they did not get deeply involved in negotiations until after preliminary budgets had been set and transportation agencies had to react through comments. Overall, this

involvement represents a major change in the practice of transportation and air quality planning. Even

where bureaucratic relations have not been smooth, the previously separate planning and regulatory

processes have become far more tightly linked than ever before. 

Conformity has spurred this process in two main ways: (1) by stimulating greater scrutiny of

and refinements in the current data and forecasting techniques for transportation demand, and (2) by

forcing planners and policy makers to identify, confront, and more directly assess the options they

have for reducing mobile source and other emissions. 

The complexity of the modeling process and the inter-relationships between conformity and

SIP modeling, however, have sometimes made it difficult to get to the heart of these issues. All of

the areas that have had serious problems passing the budget tests (Atlanta, Charlotte, Denver,

Houston, and Salt Lake City) initially responded by attempting to alter the modeling underlying

mobile source emission budgets or to enlarge the mobile source share of the aggregate budget to

accommodate high VMT growth rates.

Although the conformity rule does not require areas to put TCMs in the SIP, some environmentalists believed that the protection given SIP TCMs would encourage areas to do so. During the

initial round of SIP planning, however, conformity proved to be a disincentive for inclusion of TCMs

in SIPs because delay of a SIP TCM could cause a conformity lapse, jeopardizing the flow of federal

funding for all transportation projects. Portland is the only study area that placed TCMs in the SIP

specifically to ensure their implementation even if political opposition arose.

Some areas considered the ramifications of conformity when choosing SIP measures other

than TCMs. With the notable exception of Phoenix, however, few adopted mobile source control

measures that were not mandated by the CAAA. Three study areas (Chicago, Houston, and Phoenix)

requested NOx waivers, at least in part to avoid problems with the conformity NOx build/no-build

tests. Denver adopted air quality measures outside of the SIP to pass PM10 conformity, while avoiding the hurdles of an amendment to add measures to the SIP. In Maryland, although conformity did

not influence the initial form of the state inspection and maintenance (I/M) program, the governor

vetoed a bill adopted by the legislature in 1997 that, by making I/M voluntary, would have resulted

in EPA disapproval of the Baltimore SIP and imposition of a conformity freeze.

CHAPTER 6: TOWARD A NEW PLANNING “ARENA”

Planning Improvements. The interviews conducted for this study reveal a broad professional consensus that conformity-related improvements in planning methods are genuine and valuable

not only for air quality regulation but also for other planning purposes. Conformity requires transportation planners to use advanced analytic tools and the latest available planning assumptions to
 Executive Summary: Linking Transportation and Air Quality Planning xviii

forecast transportation demand and mobile source emissions. Coupled with the infusion of ISTEA

funds to hire technical staff and collect more recent, often more detailed, data about demographic

trends, land use, and travel behavior, conformity has thus led to significant improvements in planning

capabilities in all of the study sites, though in varying degrees. Improvements in transportation planning have served not only to focus transportation planners on the goals and requirements of the Clean

Air Act but also have had a direct effect on air quality planning.

Divergent Perspectives on Regulation. It is important to distinguish, however, between acceptance of air quality analysis for planning purposes as opposed to regulatory purposes.

Conformity shapes key policy decisions, allotments of large sums of federal aid, and legal authority

to proceed with projects. As a result, many transportation and air planners continue to have

significant differences about how the conformity analysis is conducted and what impacts it has on the

quality of decision making.

Some transportation planners resent the absolute priority that air quality goals have over all

other goals in transportation planning. Many question the validity of using the model outputs for

making conformity determinations, arguing that conformity conveys a false image of precision. These

feelings are sometimes intensified because of inconsistencies between the planning assumptions

incorporated in SIPs and those in the conformity analysis. These inconsistencies do not always make

it more difficult to demonstrate conformity. If they do, though, transportation planners often express

frustration that the complexities and slowness of the state regulatory and federal approval processes

make it quite time consuming – and often impractical within the time frame of regular transportation

planning cycles – to update SIP planning assumptions.

By contrast, many air planners and environmental advocates contend that the modeling results

provide a sufficiently good approximation of current reality and future development patterns to

warrant their use for conformity, especially given their view that it is critically important to achieve

Clean Air Act goals. Others argue that emission models underestimate mobile source pollution, so

that transportation projects get the benefit of the doubt. Some suspect that MPOs shade the

transportation demand analysis to produce favorable results.

Another divergence in the perspectives of transportation and air planners results because conformity permits the modeling to take “credit” for improvements in vehicle emission control systems

or beneficial changes in fuel composition only when these are mandated by federal regulations and/or

adopted in legally enforceable regulations by the state. Many transportation planners and advocates

regard this as an artificial feature of the planning system. They contend that it is poor policy to be

forced to forgo transportation projects which would otherwise be permissible simply because the time

frame of decision making on national technology policies is independent of – and therefore imperfectly synchronized with – the timing of their conformity decisions. By contrast, many air agencies

and environmental advocates assert that until such controls are legally mandated, it is inappropriate

for conformity to recognize still-speculative emission reductions. Once transportation projects are

approved, they argue, it is difficult or impossible to halt them or scale back if emission reductions

from technology measures do not materialize.

Confronting Conformity Difficulties. In the framework of the CAAA of 1990, conformity is an analytic “trip-wire” to alert policy makers to inconsistencies between two sets of policies

– air quality planning (codified in state implementation plans) and transportation planning (codified
 Executive Summary: Linking Transportation and Air Quality Planning xix

in transportation plans and programs). In the 15 study sites, this reconsideration tends to occur in

distinct phases. First, planners carefully re-examine the modeling on which the conformity analysis

is based to confirm that a problem exists and to discover its magnitude. When conformity difficulties

are significant, they must then deal with the institutional and political dynamics of changing either the

transportation plan/program or the applicable SIP so that conformity can be demonstrated.

Through the process of reconsidering planning assumptions and modeling techniques, the

transportation agencies seek to reduce the possibility that conformity penalties might result from

“technical” difficulties in the modeling rather than “real” future problems revealed by conformity forecasting of emissions. Environmental agencies, in turn, seek to discover whether the analysis has been

conducted appropriately and whether genuine conformity problems exist. As a result of such scrutiny

on both sides, errors have been discovered, improved estimates of key parameters have been secured,

and refinements of modeling methods have been introduced.

Within the community of core conformity stakeholders – transportation and air agencies and

active stakeholder groups – the character of the consultation process appears to have important consequences for the credibility and longer term effects of the analytic process. In areas with less intense

interagency consultation practices, reassessment of modeling methods is likely to be performed primarily by MPO staff, sometimes with little visibility to other agencies and stakeholders. But MPO

autonomy comes at a cost: reduced confidence by outsiders in the results. By contrast, when the analytic issues of conformity have been the focus of careful “upfront” discussion and debate among

interested agencies and stakeholders, transportation planners are more likely to regard any remaining

problems in demonstrating conformity as “real” rather than modeling artifacts; and air planners and

advocacy groups are less likely to harbor suspicions that conformity has been demonstrated by technical manipulation. As successive cycles of conformity analysis are undertaken, effective interagency

consultation creates greater mutual confidence in the analytic process.

The professionals, however, are not conformity’s only “audience.” Conformity was also

clearly intended to get policy officials, elected executives, legislators, and a broad array of stakeholder

groups to confront the policy dimensions and tradeoffs of transportation and air quality. Data from

the 15 study sites, however, suggests that it can sometimes be problematic to move discussion of

conformity problems beyond the relatively small circle of transportation and air quality professionals

and the few stakeholder representatives who deal with it on a regular basis. In some of the study

areas, this has led to considerable delay in confronting the roots of their conformity problems.

Responding to Conformity Problems. In the event of conflict between transportation

plans and air quality commitments, the conformity regulations permit an MPO or state, in principle,

to resolve the inconsistency by making changes to transportation plans/programs, SIPs, or both. As

a practical matter, however, it has often proven more difficult to make such changes than some of the

architects of conformity anticipated.

To disaggregate the final package of projects that appear in a regional transportation plan or

program is politically arduous and time consuming. Many environmental advocates and air planners

have been frustrated that the transportation planning/programming process has proven less pliable

than they hoped or expected. This problem is exacerbated by the weak link between transportation
 Executive Summary: Linking Transportation and Air Quality Planning xx

planning and land use regulation that exists in virtually all of the study sites, except Portland.

Seeking changes on the air quality side – i.e., in the state implementation plan – encounters

other kinds of difficulties. Depending on the state, this may take many months, sometimes more than

a year. To go through the SIP revision process is almost always to delay the normal schedule for

developing and initiating new plans/programs. Seeking changes in a SIP is also burdensome for air

planners. They often have competing priorities for time and resources, including meeting new SIP

development responsibilities. Not unlike the political process that produces transportation plans,

emission budgets usually represent consensus policies established after long periods of negotiation

among stakeholders from different emission-source sectors. Reopening budget allocation decisions

can ignite politically potent inter-sectoral disputes. Air planners are therefore often reluctant to manage SIP revisions.

While changing plans is difficult on both sides, it is ultimately transportation plans that are

placed at risk by conformity difficulties. This was clearly intended by the legislative architects of the

conformity provision of the CAAA of 1990. But it is also true that the officials with direct responsibilities for the program at risk – in MPOs and state DOTs – have direct influence over only

some of the potential ways of resolving inconsistencies between transportation and air quality plans.

To the extent, therefore, that conformity is meant to allow even-handed consideration of the means

of resolving inconsistencies between transportation and air quality plans, the difficulties in changing

SIPs and the disparities in the timing of the two planning processes is problematic.

Conformity as an Evolving Process. This study is a snapshot of conformity during a

particular period; but like any regulatory process, conformity is evolving and responding to new

situations. In addition to the issues noted, conformity must adapt to the new National Ambient Air

Quality Standards for ozone and particulate matter, which will make new areas subject to regulation.

New tools for analyzing transportation demand and the effects of transportation policies on pollution

are in development. The impact of conformity over the long run on transportation planning/programming may be greater than it has been to date – as new plans and projects take account of conformity

in their formative stages, not just as they are being finalized.
LINKING TRANSPORTATION AND AIR QUALITY PLANNING:

IMPLEMENTATION OF THE 

TRANSPORTATION CONFORMITY REGULATIONS 

IN 15 NONATTAINMENT AREAS

Arnold M. Howitt and Elizabeth M. Moore

Taubman Center for State and Local Government

John F. Kennedy School of Government

Harvard University

March 1999

A Report to the

U.S. Environmental Protection Agency

and the

Federal Highway Administration,

U.S. Department of Transportation

Publication Number

EPA420-R-99-011

CHAPTER 1: THE CONFORMITY ASSESSMENT PROJECT
Chapter 1

THE CONFORMITY ASSESSMENT PROJECT

The Clean Air Act Amendments of 1990 require far-reaching efforts to assure that transportation investments in nonattainment and

maintenance areas are consistent with state

commitments to meet national air pollution

standards. The statutory mandate was implemented through major federal regulations

issued in November 1993 by the U.S. Environmental Protection Agency, with the

concurrence of the U.S. Department of Transportation. Known within the transportation

and air quality professional communities as the

“transportation conformity” (or “conformity”)

rule,1 these regulatory procedures have raised

the hopes of many for improvements in

transportation decision making, while also motivating considerable criticism from some

affected agencies and concerned stakeholders.

Project Purposes

The research reported here, jointly initiated

by the U.S. Environmental Protection Agency

and the Federal Highway Administration, was

planned as Phase 1 of a comprehensive

Conformity Assessment Project. By carefully

examining experience in 15 areas, the research

will document and develop a better understanding of how the transportation conformity regulations have been implemented and

with what early effects on transportation

planning and air quality regulation at the metropolitan and state levels.

The overall study was undertaken to inform

and stimulate further thinking about conformity

in the transportation and air quality practitioner

communities. It was also intended to provide

information to elected officials, stakeholder

groups, and interested citizens about an

important effort to coordinate and make

consistent the effects of federal transportation

and air pollution policies, which in the past

have operated quite independently. More

specifically, the research reported here was

designed to discover:

• the ways in which conformity works effectively and achieves its intended ends,

• the ways in which conformity has been

problematic – and why – and how areas

have dealt with these problems,

• conformity challenges for the future.

Phase 1, reported on here, covers the period

from 1991 through January of 1998, which includes experience under the Interim Conformity

guidelines issued by EPA and DOT in 1991 and

under the November 1993 conformity regulations. Phase 2 will revisit the issues of Phase 1

after several more years of experience, focusing

particularly on whether and how the 1997 conformity amendments, as well as further implementation of other aspects of the 1990 CAAA,

have affected how conformity works at the met1All references to “conformity” in this report relate

to the “transportation conformity” regulations, which

apply only to highway and transit projects. The CAAA

of 1990 also require “general conformity” procedures

for other federal projects/actions. 
 Chapter 1: The Conformity Assessment Project 2

ropolitan and state levels.

Although no study of conformity can ignore

the technical issues of transportation and air

quality modeling that are central to the practice

of conformity, this research was intended to

deal primarily with institutional impacts, effects

on planning process, and substantive planning

outcomes. We have inquired how the conformity modeling requirements have affected institutional development in the study sites and how

the modeling process and results have shaped

the conformity decision-making. It should be

carefully noted, however, that the study was

not designed to provide a careful examination,

let alone an evaluation, of modeling practices in

each study site, nor to assess more generally

the technical dimensions of the conformity

process. Conclusions about the technical dimensions of transportation and air quality modeling are beyond the scope of this research. 

Focal Questions

Three overarching questions have organized this research: 

(1) How has conformity affected key

agencies and constituencies’ organizational

capacity and relationships? Conformity tests

organizational capacity in at least two ways.

First, it makes technical and analytic demands

on involved agencies and stakeholder groups.

The core public agencies responsible for the

analysis need not only computer modeling

proficiency to forecast regional transportation

patterns and associated pollution but also the -

capacity to evaluate the forecasts and help

policy makers understand their implications.

Other agencies and stakeholders that do not

themselves perform modeling tasks nonetheless

require sufficient technical sophistication to

assess the process and evaluate policy options

and impacts. Second, through the interagency

consultation process, conformity requires the

development of institutional relationships that

did not previously exist in most locales.

Conformity seeks to coordinate transportation

and air quality – formerly nearly independent

policy systems – and foster collaboration

among agencies and constituency groups that

historically have had very different

perspectives. In some jurisdictions, indeed,

these stakeholders viewed each other with deep

suspicion or had clashed on policy matters.

This cooperation was supposed to occur in the

larger context of the ISTEA-mandated

transportation planning process, which involves

many planning factors other than air quality

conformity.

Recognizing these demands, the research

looked closely at institutional issues. How well

have agencies and stakeholders coped with and

adapted to the technical and coordination

requirements of conformity? Did they have

sufficient resources to manage its demands, or

did they have to upgrade their organizational

capacity and build new relationships? What

positive practices have developed? What

problems have arisen – and why?

(2) How has conformity changed the

transportation planning/programming process and its results? Conformity places new

demands on the transportation planning and

programming process, in conjunction with elements of ISTEA that mandate broader par-
 Chapter 1: The Conformity Assessment Project 3

ticipation in planning and fiscal constraint of

plans. Planners and decision makers in nonattainment areas must give air quality a far more

prominent place in their considerations. In the

face of potential financial penalties and

restrictions on their ability to proceed with new

transportation projects, they must assure that

their policies and investment choices – assessed

over a 20-year time horizon – are consistent

with commitments made by their state to reduce pollution levels. 

The research therefore asked how transportation planners and policy makers have adapted their previous practices to fulfill the obligations of the conformity regulations. It explored the organization of the transportation planning process, patterns of participation and interagency coordination, specific roles played by

different types of agencies and stakeholders, and

whether and how the outcomes of the

planning/programming process were materially

changed by conformity requirements. The research looked both for notable conformity-related

innovations in the conduct of transportation

planning and for problems and dilemmas created

for planners and policy officials by the 1993

conformity regulations.

(3) How has conformity changed air

quality planning and regulation? The conformity regulations seek to assure that decisions made in transportation policy are consistent with the requirements of the Clean Air

Act Amendments of 1990 and with the specific

planning and regulatory actions that each state

is taking to reduce pollution to the levels mandated by the CAAA. In making this connection, however, the regulations anticipate that

issues that arise in transportation planning will

in turn affect the choices that state officials

make in pursuing air quality goals.

The study therefore inquired how transportation conformity has affected air quality planning and regulation. Specifically, it inquired

whether and how conformity has affected civic

debate about transportation goals and their

interaction with air quality goals, whether

conformity has affected the emission budgets

developed in State Implementation Plans under

the CAAA of 1990, and whether conformity

has affected the inclusion of transportation

control measures (TCMs) and other mobile

source controls in SIPs.

Selection of the Research Sites

To ground the study in the realities of actual practice and to gather data, the researchers,

in consultation with staff in the Environmental

Protection Agency and the Federal Highway

Administration, selected 15 nonattainment

areas for careful study. (See Figure 1-1.) Ten

of the selected areas – marked by an asterisk

below – had been studied by one of the

researchers in a previous project (1992-1994)

conducted on behalf of EPA and FHWA. The

earlier research had more generally investigated

implementation of the transportation provisions

of the CAAA of 1990 and the air quality provisions of ISTEA.2

 Five additional areas were

2

For results of that study, see Arnold M. Howitt,

Joshua P. Anderson, and Alan Altshuler, The New Politics of Transportation and Clean Air (Cambridge, MA:

Harvard University, John F. Kennedy School of

Government, Taubman Center for State and Local Government, November 1984; also published by the U.S.

Department of Transportation, Federal Highway Administration, FHWA-PD-97-010, DOT-VNTSCFHWA-97-5, February 1997); and Joshua P. Anderson
 Charlotte, NC

.

.

Houston, TX

San Francisco, CA .

.

Denver, CO

Salt Lake City, UT .

.

Phoenix, AZ

.

Atlanta, GA

. Boston, MA

.

Northern NJ

. New York, NY

.

Philadelphia, PA

.

Baltimore, MD

Chicago, IL .

.

Milwaukee, WI

Figure 1-1

Nonattainment Areas in the Study

Portland, OR .
 Chapter 1: The Conformity Assessment Project 5

selected for the current study specifically because they were perceived by the federal

agencies or the researchers to have had “interesting” conformity experiences that warranted

examination. The 15 nonattainment areas

selected for this research are:

• Atlanta, Georgia,*

• Baltimore, Maryland,*

• Boston, Massachusetts,*

• Charlotte, North Carolina,*

• Chicago, Illinois,*

• Denver, Colorado,

• Houston, Texas,*

• Milwaukee, Wisconsin,*

• New York, New York

• Northern New Jersey

• Philadelphia, Pennsylvania,*

• Phoenix, Arizona,*

• Portland, Oregon,

• Salt Lake City, Utah*

• San Francisco, California

Table 1-1 provides information about population growth and auto usage in these 15 study

sites.

The selected areas were not meant to constitute – nor are they – a random sample of

nonattainment areas subject to the 1993 conformity rule. Instead, they were selected to

concentrate on large metropolitan areas with

more severe air pollution problems (with a primary, but not exclusive, emphasis on ozone).

As shown in Table 1-2, 13 of the selected areas

were classified at least “moderate” for ozone,

and 10 of these were in nonattainment status

for at least one other pollutant. In addition,

Denver (transitional for ozone) was a

“moderate 2” area for carbon monoxide and

“moderate” for particulate matter, while Portland (marginal for ozone) was also a “moderate

1” area for carbon monoxide. (Some of these

areas have subsequently been reclassified, as is

also indicated in Table 1-2.) Beyond these

criteria, the researchers sought to assure

diversity by including:

• nonattainment areas in all regions of the

country;

• areas growing rapidly in population and

geographic spread, as well as those that

were growing much more slowly in

those respects;

• areas with mature highway systems and

substantial transit usage, as well as

those significantly adding to their highway networks and currently having

more limited transit systems.

In making these selections, the researchers

and sponsors believed that this sample of 15 research sites provided a significant number of individual cases that varied in several respects

potentially relevant to conformity. They felt

that an intensive examination of the conformity

process in these jurisdictions would shed important light on how the new regulations were

being implemented in major areas, identify situations in which effective implementation

strategies were being employed, and reveal and Arnold M. Howitt, “Clean Air Act: SIPs, Sanctions, and Conformity,” Transportation Quarterly

(Summer 1995). 
Table 1-1

GROWTH RATES OF POPULATION AND VEHICLE MILES TRAVELED, BY STUDY SITE

1980 1990 1995

Percent 

Annual 

Growth ('80-

'90)

Percent 

Annual 

Growth 

('90-'95)

Percent 

Annual 

Growth 

('80-'95) 1990

Percent 

Annual 

Growth ('90-

'95 or 

'90-'96)

VMT Per 

Capita ('95 

or '96)d

Atlanta 1,989,341 2,653,159 3,038,050 2.9% 2.7% 2.9% 81,472,984 105,218,456 ** 4.4% 34.6

Baltimore 2,173,989 2,348,219 2,432,993 0.8% 0.7% 0.8% 49,900,000 55,900,000 * 2.3% 23.0

Boston 4,945,835 5,204,103 5,274,317 0.5% 0.3% 0.4% 59,816,200 64,412,700 ** 1.2% 12.2

Charlotte 566,838 686,574 760,939 1.9% 2.1% 2.0% 14,515,000 18,442,000 * 4.9% 24.2

Chicago 7,171,420 7,332,926 7,641,329 0.2% 0.8% 0.4% 127,402,856 140,834,243 * 2.0% 18.4

Denver 1,618,461 1,848,319 2,085,158 1.3% 2.4% 1.7% 39,100,000 50,900,000 ** 4.5% 24.4

Houston 3,118,480 3,731,029 4,164,393 1.8% 2.2% 2.0% 90,400,000 105,800,000 * 3.2% 25.4

Milwaukee 1,693,289 1,735,364 1,780,769 0.2% 0.5% 0.3% 33,072,000 35,900,000 * 1.7% 20.2

No. New Jersey 4,961,510 5,108,929 5,243,598 0.3% 0.5% 0.4% 125,153,923 129,352,902a

** 0.6%b24.7

New York 11,063,184 11,379,764 11,462,260 0.3% 0.1% 0.2% 133,577,052 132,284,161 * -0.2%c

11.5

Philadelphia 3,682,450 3,728,991 3,731,703 0.1% 0.0% 0.1% 64,565,000 70,195,000 ** 1.4% 18.8

Phoenix 1,600,093 2,238,498 2,563,582 3.4% 2.7% 3.2% 49,600,000 57,000,000 * 2.8% 22.2

Portland 1,050,418 1,174,291 1,300,729 1.1% 2.1% 1.4% 20,413,000 22,437,000 * 1.9% 17.2

Salt Lake City 765,606 913,897 1,023,765 1.8% 2.3% 2.0% 20,130,479 25,864,357 ** 4.3% 25.3

San Francisco 5,179,759 6,020,147 6,302,933 1.5% 0.9% 1.3% 113,389,000 123,666,900 * 1.8% 19.6

VMT

1995* or 1996**

NONATTAIN-MENT 

AREA

POPULATION

a

1999 VMT.

b

1990-1999.

c NYMTC does not regard negative VMT growth in this period as indicative of future trends.

d

1996 per capita rates are calculated using 1995 population.
Table 1-2 

Nonattainment Classifications for Study Sites by Pollutant

NONATTAINMENT AREA 1990 OZONE 1990 CARBON MONOXIDE 1990 PM-10

Atlanta Serious

Baltimore Severe 1 Moderate 2

Redesignated to Attainment 1995

Boston Serious Moderate 2

Redesignated to Attainment 1996

Charlotte Moderate

Redesignated to Attainment 1995

Not Classified

Redesignated to Attainment 1995

Chicago Severe 2 Moderate

Denver Transitional Moderate 2

Reclassified to Serious 1997 Moderate

Houston Severe 2

Milwaukee Severe 2

Northern New Jersey Severe 2 Moderate 2

New York Severe 2 Moderate 2 Moderate

Philadelphia Severe 1 Moderate 1

Redesignated to Attainment 1996

Phoenix Moderate

Reclassified to Serious 1997

Moderate 1

Reclassified to Serious 1996

Moderate

Reclassified to Serious 1996

Portland Marginal

Redesignated to Attainment 1997

Moderate 1

Redesignated to Attainment 1997

Salt Lake City Moderate

Redesignated to Attainment 1997 Not Classified Moderate

San Francisco

Moderate

Redesignated to Attainment 1995; Proposed

Reclassification to Nonattainment 1997

Moderate 1

Redesignated to Attainment 1998

7
 Chapter 1: The Conformity Assessment Project 8

problems that had emerged from this

experience. It is worth noting, however, that

the sample does not include rural nonattainment

areas, small metropolitan areas, or areas with

minimal pollution problems. So the research

findings should be interpreted cautiously if

interest focuses particularly on such areas.

Research Methods and Data

Data for this study was collected primarily

during the period from fall 1996 through spring

1998, with some additional work conducted

until February 1999. In the course of the

project, the researchers gathered and assessed

several types of information about the 15 study

sites:

• Background data was compiled on all

study areas, including official documents prepared in the course of their air

quality and transportation planning,

local newspaper reporting (primarily

identified through NEXIS searches),

articles in national newsletters,3Federal

Register notices and regulations

pertaining to each area, selected documents from EPA and FHWA files, and

other materials provided by interview

subjects.

• In ten of the nonattainment areas, the

researchers consulted records of their

interviews (primarily with staff members of MPOs, air agencies, and state

DOTs) conducted for the earlier Harvard study during the period from the

fall of 1993 through early 1996.4

• In each of the 15 study sites, new personal interviews were conducted with

between 11 and 23 individuals knowledgeable about conformity. In all

areas, interview subjects included representatives from the MPO, state air

agency, state DOT, EPA and FHWA

field offices, and environmental advocacy groups. In some areas, interviews

were also conducted with state legislative staff, regional or local air agency

officials, representatives of other

stakeholder groups (primarily business

associations), and other knowledgeable

observers. In all, the researchers spoke

with more than 230 people involved

with conformity in the 15 study sites.5

Interviews were conducted using semistructured, elite interview techniques. In other

words, the researchers did not conduct a survey

with a fixed set of questions asked of each

subject and then tabulate the results. Instead,

the interviews began with a set of basic

questions that were adapted – often extensively

– for each subject to take account of the locale,

3

These included, particularly, Clean Air Report,

Mobile Source Report, Links, and Transportation and

Clean Air Report.

4

Information had been collected in person in Boston, Chicago, Houston, and Salt Lake City and by telephone in the remaining six sites. 

5During the conformity study, the researchers visited seven research sites – Boston, Denver, New York,

Northern New Jersey, Portland, San Francisco, and Salt

Lake City. Telephone interviews supplemented inperson interviews in these sites. In the remaining research areas, all interviews were conducted by telephone. The typical interview was one hour in length,

with the range approximately a half hour to about three

hours. A large majority of the interviews were conducted with individual respondents, but some interviews

involved two or more respondents at the same time.
 Chapter 1: The Conformity Assessment Project 9

the institutional and professional perspectives

to which that respondent could speak, and the

specific experiences that each respondent had

had with conformity. As a particular interview

unfolded, the researchers frequently asked

questions and explored issues that during their

preparations they had not anticipated covering

with that subject.

Most information was provided by respondents on the record, but occasionally specific

comments were provided on a not-for-attribution or background basis. All of the respondents agreed to allow us to cite their names as

sources for the study. Most respondents were

familiar with only one research site, but a few

(generally federal agency officials or representatives of national environmental advocacy

organizations) were knowledgeable about more

than one.

Since no interview was exactly the same as

any other, this research method precludes tabulation and quantitative analysis of responses to

particular interview questions. On the other

hand, the researchers were provided with rich,

detailed descriptions of the conformity process

in each research site, described from a variety

of perspectives. Our respondents provided

specific accounts of events and institutional

relationships in their own locales and shared

their insights and evaluative judgments about

how conformity is working.

Once this information was compiled, the researchers conducted an intensive within-site

and cross-site analysis, seeking to understand

the conformity process and the relationships it

has created. The findings, generalizations, and

conclusions reported here are based on the 15

nonattainment areas in which research was conducted, but the research was sufficiently

broadly based to generate plausible hypotheses

about what might have been discovered in a

more inclusive examination of conformity implementation in major metropolitan areas.

The Research in Perspective

The value of this research thus lies in its description and interpretation of the working experience of 15 major nonattainment areas with

this important regulatory mandate. The data

available is rich enough to provide a nuanced

perspective on institutional relationships in specific areas and to judge whether the experience

of individual areas reflects common experiences

or special circumstances. The time period

investigated is long enough that difficulties

associated with the conformity “start-up” can

be placed in the perspective of a few more

years of experience during which agency

working relationships have been established and

new analytic procedures have become more

familiar. Some early problems have been

surmounted, some have not, while other issues

have emerged that deserve future study and

analysis. 

Although this research does not attempt to

evaluate the technical dimension of conformity

modeling, it seeks to place the technical

process in the larger context of the institutional

relationships involved, which more technicallyoriented research rarely does in any detail.

Any full assessment of conformity, however, is bound to be provisional at this time. By
 Chapter 1: The Conformity Assessment Project 10

its nature, conformity’s influence must be

judged in a more extended time frame, as transportation and air planning processes continue

to adapt, expectations and practices evolve, and

investment and policy decisions are made and

implemented. Since early 1998, events in

several of the study sites – including Atlanta,

Charlotte, and northern New Jersey – have

occurred that deserve careful analysis. That is

why a second phase of the Conformity Assessment Project has been planned by EPA and

FHWA from the outset.

Nonetheless, the regulatory process does

not stand still awaiting formal policy evaluations. Amendments to the regulations and

changes in state and regional practice have been

made – and may be made again – in light of

experience. Even provisional information,

systematically collected and assessed, can be

extremely valuable. In presenting the findings

of this report, the researchers have sought to

provide sufficient information about the research sites to allow readers of this report to

assess the interpretations and conclusions for

themselves. It is therefore hoped that both the

data and the findings will prove useful in ongoing policy discussions about conformity at

the metropolitan, state, and national levels.

Outline of the Report

• Chapter 2 examines the purposes and

requirements of the transportation conformity regulations. Following a short

history of efforts prior to the CAAA of

1990 to coordinate transportation

investments and air quality regulation,

it analyzes the purposes of the

conformity regulations as derived both

from the statute and regulations and

from a broader set of stakeholder expectations. It also describes what the

1993 regulations require of transportation planners and other stakeholders.

• Chapter 3 provides an overview of how

the conformity regulations have been

applied in the 15 study sites and what

difficulties were experienced by each

area in applying the several conformity

tests.

• Chapter 4 examines how conformity

has connected transportation and air

quality planning, concentrating on institutional and process issues. It focuses

initially on the institutional context in

which the 1993 regulations were

implemented. Then it explores the

roles played by different types of participants – MPOs, state air agencies,

state transportation agencies, the

federal agencies, and environmental and

business stakeholders – as conformity

has become an integral part of

transportation planning. Finally, it assesses the extent to which conformity

has led to the attentiveness and involvement of elected officials and the general

public in transportation and air quality

issues.

• Chapter 5 explores the impacts of conformity on the substance of both transportation and air quality plans in the

study sites. It asks whether the practice

of conformity has modified decisions

about highway projects, transit, other

TCMs, and land use policies. It also
 Chapter 1: The Conformity Assessment Project 11

examines whether, in turn, conformity has led

to changes in air quality planning.

• Chapter 6 reviews the major findings of

the report, assessing the extent to

which conformity has created a new

“planning arena” that genuinely links

transportation and air planning. 

• Following the body of the report, an

appendix provides capsule histories of

the conformity experiences of each of

the 15 study sites.

• Another appendix identifies the interview respondents whose accounts and

observations form the key source of

project data in each study site.

• Additional appendices provide a glossary, identify the sources of population

and transportation data for the study

sites, and provide information about the

authors.
LINKING TRANSPORTATION AND AIR QUALITY PLANNING:

IMPLEMENTATION OF THE 

TRANSPORTATION CONFORMITY REGULATIONS 

IN 15 NONATTAINMENT AREAS

Arnold M. Howitt and Elizabeth M. Moore

Taubman Center for State and Local Government

John F. Kennedy School of Government

Harvard University

March 1999

A Report to the

U.S. Environmental Protection Agency

and the

Federal Highway Administration,

U.S. Department of Transportation

Publication Number

EPA420-R-99-011

CHAPTER 2: THE PURPOSES AND REQUIREMENTS

OF TRANSPORTATION CONFORMITY
Chapter 2

THE PURPOSES AND REQUIREMENTS OF

TRANSPORTATION CONFORMITY

What is conformity intended to accomplish? By what regulatory mechanisms does it

seek these objectives? This chapter sets the

conformity process derived from the CAAA of

1990 in context by briefly examining the development of federal environmental controls

on transportation planning and investment. It

then examines the purposes of conformity and

the broader climate of expectations that the

regulations have engendered among

stakeholders. Finally, the chapter examines in

depth the specific requirements of conformity

as laid out in the statute, the 1993 regulations,

and subsequent amendments to those

regulations.

Policy Antecedents

Environmental advocacy groups were the

leading proponents of the conformity provision

of the Clean Air Act Amendments of 1990.

Their efforts to see such a requirement included

in the law stemmed to a great degree from their

dissatisfaction with the effects of a series of

previous federal regulatory initiatives. These

initiatives, beginning in 1969, sought to assess

the environmental effects of specific road-building proposals prior to allowing construction and,

more generally, to promote transportation policies contributing to achievement of the nation’s

environmental goals. From the perspective of

environmental advocates, these policies fell short

of these objectives, leading the legislative architects of the CAAA of 1990 to craft stronger

requirements.

The National Environmental Policy Act

(NEPA) of 1969 created a regulatory tool –

environmental impact analysis – to ensure that

the potential environmental consequences of

development projects, including road-building

proposals, would be considered in decision

making. From the environmental perspective,

however, NEPA had two significant

drawbacks. First, although it establishes

procedural requirements for environmental

analysis, the law did not provide substantive

guidelines for determining which projects

should proceed. Therefore, it did not prevent

decision makers from moving ahead with

projects that have adverse environmental impacts, as long as these were considered in the

environmental analysis. Second, NEPA’s

project-by-project focus did not sufficiently

address cumulative air quality effects – for

example, how transportation projects would

affect regional emissions of pollutants.

Environmentalists therefore sought a more

systemic regulatory approach through successive iterations of the Clean Air Act. Early

efforts to create strong links between air

quality regulation and transportation planning,

however, encountered many institutional

problems and resistance. Until the CAAA of

1990, neither federal law nor the practices of

metropolitan transportation planning provided

clean air advocates and regulators with much

leverage on highway or transit investments.

An initial, unsuccessful effort to connect
Chapter 2: Purposes and Requirements of Transportation Conformity 13

transportation investment policies to air quality

regulation came in conjunction with the CAAA

of 1970. In Section 109(j) of the Federal-Aid

Highway Act of 1970, Congress required the

Secretary of Transportation, in consultation

with the Administrator of the Environmental

Protection Agency, to issue regulations for the

purpose of assuring that federally assisted

highway projects would be “consistent” with

the air quality plan for each pollution control

area. The draft regulations became mired in

disagreement between the federal agencies,

however, and were not finally issued until

1975. They were extremely vague, moreover,

on the crucial question of how consistency

should be determined; and, to the

disappointment of environmental advocates,

they gave state transportation officials rather

than environmental regulators the responsibility of making consistency determinations.

 In most areas, EPA regional offices – politically beset, understaffed, and preoccupied

with other responsibilities, including the need

to develop the extremely controversial

Transportation Control Plans of the early

1970s – made little effort to activate Section

109(j). Where they did, the effect was

minimal. EPA’s particularly aggressive New

England regional office, for example, was rebuffed by state transportation officials when it

tried to claim a veto over Boston area

transportation projects.1 There as elsewhere,

agency officials had very little training or

experience in the field of transportation. Nor

were they tied into institutional and personal

networks of transportation officials. This

severely limited the agency’s capacity for

information gathering, constructive discussion,

formulation of policy alternatives, persuasion,

and tactical flexibility in seeking its goals. 

The 1977 CAAA contained stronger language. It prohibited metropolitan planning organizations (MPOs) from adopting a “project,

program, or plan” that did not “conform” to

the provisions of an approved State

Implementation Plan, and it authorized the

U.S. Secretary of Transportation to withhold

federal highway aid upon a finding of nonconformity. FHWA was assigned responsibility to monitor compliance with the conformity requirement, in consultation with EPA.

After extended negotiations, FHWA and EPA

operationalized the conformity requirement in

a 1978 Memo of Understanding which spelled

out in general terms how consultation between

transportation and air planners should occur

and how the two planning processes should

relate. As a practical matter, however, the

conformity procedure specifically required

only that states assure the timely

implementation of transportation control

measures they elected – at their own initiative

– to include in their SIPs; and federal

enforcement was weak. Consequently, the

conformity requirement of the 1977 CAAA

was a negligible factor in transportation investment decision making. The Secretary of

Transportation never penalized a state financially for violating the conformity requirement,

though environmental advocates occasionally

used conformity as a litigation “hook,” most

successfully to challenge transportation

1See Mark Garrett and Martin Wachs, Transportation Planning on Trial: The Clean Air Act and Travel

Forecasting (Thousand Oaks, CA: Sage Publications,

1996) and Arnold M. Howitt, Managing Federalism:

Studies in Intergovernmental Relations (Washington,

D.C.: CQ Press, 1983).
Chapter 2: Purposes and Requirements of Transportation Conformity 14

planning methods in the San Francisco Bay

area.2

Purposes and Expectations

The CAAA of 1990, reinforced by the

Intermodal Surface Transportation Efficiency

Act (ISTEA) of 1991, required much tighter

integration of regional air quality and transportation planning than its predecessor, most

notably in its invigorated transportation conformity provisions. Ultimately, pollution reduction to meet national air quality standards

and achieve the resulting public health benefits,

were the primary goals of these provisions.

But the statute – and the regulations promulgated by EPA to implement them – implied

a broader set of purposes than this ultimate

goal; and various stakeholder groups layered

on additional expectations about how

conformity would work and what it should

accomplish. These extended purposes and

expectations included:

C establishment of a procedural framework and incentives for analyzing

transportation-related pollution,

C improvements in both transportation

and air planning processes and establishment of tighter connections between them,

C improvements in public deliberation

about and decisions on transportation

and air quality issues, and

C advancement of certain additional elements of the environmental advocacy

agenda.

Therefore, before examining the detailed

conformity requirements, it is worthwhile to

discuss these goals and expectations further.

Each suggests a different lens through which

to view and evaluate the conformity process,

as it has actually been implemented in the 15

study sites. This report will examine conformity impacts in light of this set of purposes and

expectations.

Pollution Reduction and Public

Health

First and foremost, the conformity process

is intended to ensure that a nonattainment (or

maintenance) area will keep transportationrelated emissions within the bounds needed to

bring the state into compliance with (or

maintain) the national ambient air quality

standards – and thus to advance the public

health goals of the Clean Air Act. Conformity

requires forecasting regional and (for certain

pollutants) localized emissions from

transportation. These projections, in turn, are

used to determine whether expected future

pollution levels jeopardize the timely achievement of the federal standards. If so,

conformity provides leverage to prevent the

use of federal funds for these investments.

A Procedural Framework and Incentives

Conformity is also intended to create a

procedural framework and organizational incentives so that the public agencies respectively responsible for transportation and air

2 quality policies will carefully analyze trans- See Garrett and Wachs (1996).
Chapter 2: Purposes and Requirements of Transportation Conformity 15

portation-related pollution. When problems

are perceived, conformity is supposed to

motivate these agencies to take steps to reduce

pollution, as needed, to achieve the federal

standards within the deadlines of the Clean Air

Act.

Procedurally, conformity relies on a performance measurement system, consultation

requirements, and stiff penalties for failing to

satisfy conformity conditions. MPOs conduct

computer simulations of transportation

demand, forecast the resultant emissions of

controlled pollutants, and then compare the

projected pollution to the permissible levels in

the state implementation plan. The conformity

regulations also require interagency collaboration both to frame these analyses and

seek solutions to any problems revealed. It is

expected that compliance will be motivated by

the desire either to achieve pollution-reduction

goals or to avoid interruptions in adopting or

implementing transportation plans and programs. Participating agencies therefore will be

inclined to develop transportation plans and

programs that can pass the conformity tests or

find ways to modify transportation or air

quality plans to do so.

The procedural framework and incentives

are expected to operate on federal agencies no

less than their counterparts at the state and

regional levels. US DOT and EPA field staff

oversee and evaluate the technical analyses, in

consultation with each other and their counterparts, to assure that federal funds are not

released to finance transportation programs

that undermine state efforts to comply with

Clean Air Act requirements.

Improving the Planning Process

A key purpose of conformity is to upgrade

the quality of both air and transportation planning and to forge strong links between these

previously autonomous planning systems. On

one side, conformity compels transportation

agencies to make air quality a key planning

factor – a criterion that is an integral part of

policy assessment and that constrains emergent

decisions about transportation investments. It

also seeks to give air agencies a far stronger

voice in the transportation planning process.

On the other side, by giving transportation

agencies a serious stake in air planning,

conformity seeks to motivate their close involvement in developing state plans to reduce

pollution. 

Better integration of transportation and air

quality planning over successive planning cycles, it was hoped, would improve the results

of each process. As new air quality plans were

developed, for example, policy makers would

be motivated to re-examine mobile source

emission budgets in light of the area’s

conformity experience to make sure that intersectoral priorities for pollution reduction were

appropriate.

Part of the thrust of conformity is to enhance the analytic tools applied to transportation and air planning. To improve data

and technical methods, the conformity regulations set standards for transportation demand

and emission modeling, require compilation of

current data, and specify how system performance must be measured. As important as these

technical processes are in the conformity

process, however, the mandated interagency
Chapter 2: Purposes and Requirements of Transportation Conformity 16

consultation process lies at the heart of

aspirations to improve the planning system.

Effective interagency consultation is regarded as a way to assure that more and better

quality information is brought to bear on transportation and air planning and to perfect the

modeling and analytic capabilities of the MPO

and other agencies. It also encourages mutual

understanding of stakeholder values and

viewpoints, promotes debate about policy

alternatives, and forces the agencies to confront policy tradeoffs. In short, improving the

planning process means more coordination,

better deliberation, and a sharper focus on the

major dimensions of choice.

Public Deliberation and Decision

Making

Some stakeholders hoped that by improving planning processes, conformity would contribute to solving a major problem that arose

under previous versions of the Clean Air Act

– the failure to engage high level officials and

the general public in serious discussion about

the causal connections between transportation

and air pollution and the policies that could

reduce transportation emissions. Although not

stated directly in the statute or regulations,

some observers regarded this outcome as a

logical consequence of the conformity process.

By gathering information, engaging agencies in

dialogue about transportation and air quality

issues, and forcing them to confront conflicts

between transportation plans and pollution

reduction commitments, conformity would

raise the public profile of these issues.

Citizens would learn more about the issues,

and elected and senior policy officials would

be compelled to address them.

Advancing the Environmental

Advocacy Agenda

Beyond the pollution reduction goals of

the Clean Air Act, many environmental advocates had firm expectations that conformity

would help promote specific elements of their

transportation policy agenda – purposes not

necessarily shared by other conformity

stakeholders. The environmentalists had long

sought a regulatory lever to influence transportation planning and investment policies,

particularly to discourage the financing of

increased highway capacity and boost mass

transit availability and convenience. Many

environmentalists argue that highway capacity

expansion, by improving access and reducing

travel times to outlying regions of the metropolitan area, are a major cause of urban sprawl

and the increasing spatial separation of jobs,

residences, and shopping. In turn, they

believe, low density development increases the

number and length of auto trips, decreases

auto occupancy rates, and diminishes the

practicality of pedestrian and transit trip

making. Similarly, they argue that roadbuilding to alleviate congestion in densely developed corridors induces additional travel,

since there is invariably a great deal of latent

travel demand in such areas, suppressed mainly

by the existing congestion. In part, this is a

case for controlling air pollution. Additional

auto travel, they believe, generally means more

pollution (though congestion relief may

temporarily reduce emissions per vehicle mile).

But concerns about highway capacity also
Chapter 2: Purposes and Requirements of Transportation Conformity 17

connect to a broader environmental policy

agenda than air quality – preserving open

space and agricultural lands, maintaining

pedestrian- and transit-friendly patterns of settlement, and conserving energy.

Consequently, many environmentalists expected that conformity, by seeking to control

air pollution, would also support a transportation agenda with more sweeping purposes. These included sharp limits on new

road capacity, increased investments in transit

service, incentives for individuals to reduce

their reliance on single-occupancy vehicles,

and land use regulation policies to promote development patterns that required less travel.

Conformity Requirements

How is this complex set of purposes – and

the broader expectations they engender – embodied in the specific requirements of the

CAAA of 1990 and the transportation conformity regulations? As noted, the core of the

conformity process are procedures intended to

ensure that a state does not undertake federally

funded or approved transportation projects,

programs, or plans that are inconsistent with

the state’s obligation to meet and maintain the

NAAQS. This is accomplished by first using

transportation demand models and mobile

source emission models to make a 20-year

forecast of emissions from the transportation

system, taking account of changing demographics, land uses, economic development,

federally mandated improvements in auto

emission systems, new transportation infrastructure and services. The predicted levels

of emissions in several milestone years are then

compared with the maximum emissions

permissible under applicable SIPs. Thus, a

conforming transportation project, program,

or plan is one that:

C does not cause or contribute to any

new air quality violation,

C does not increase the frequency or severity of any existing air quality violation, and

C does not delay timely attainment of air

quality standards or interim emission

reduction milestones.3

In the statute, Congress outlined a general

set of requirements for determining conformity. MPOs must show that expected emissions

from the transportation system are within the

mobile source emission budgets in applicable

state implementation plans (SIPs).

Transportation programs must also provide for

timely implementation of any transportation

control measure a state has included in approved SIPs. Projects must come from a conforming plan/program and must not have

changed significantly in design concept or

scope. In making conformity determinations,

MPOs must use emissions projections based

on the most recent population, employment,

travel and congestion estimates. 

 To flesh out the specific procedures and

analytic techniques to be used within this

framework, Congress required EPA to promulgate federal regulations one year from the

statute’s enactment (i.e., by November 1991).

3Clean Air Act Amendments of 1990, Public Law

No. 101-549, 104 Stat. 2399 (1990), codified as amended at 42 U.S.C.A. §§ 7401 et seq. (West, 1995). The

Transportation Conformity provision is found in § 176

(§ 7506) of the statute.
Chapter 2: Purposes and Requirements of Transportation Conformity 18

At a minimum, these regulations were to

address consultation procedures by which state

and regional agencies would confer in making

conformity determinations, the frequency of

conformity determinations, and the procedures

for determining conformity in nonattainment

and maintenance areas. One year later (i.e., by

November 1992), states were required to

adopt SIPs that would codify their conformity

procedures. Until approval of these state conformity SIPs, MPOs in ozone and CO nonattainment areas were required to show that

transportation plans and programs would contribute to annual reductions of mobile source

emissions.

The 1991 Interim Conformity

Guidance

In June 1991, US DOT and EPA jointly

issued interim conformity guidance that established temporary procedures until the federal

conformity regulations were promulgated.

The interim guidance was intended to fill a

short void but continued in place for more than

two years while the federal agencies

negotiated and solicited stakeholder comments

on the content of the regulations, not finally

promulgated until November 1993.

The interim guidance specified procedures

and analytic techniques nonattainment and

maintenance areas should follow to meet the

CAAA requirements. Among these was the

establishment of quantitative emission tests to

show that transportation plans/programs/projects were not increasing the frequency or severity of existing air quality violations and were contributing to annual VOC

and CO emission reductions. These emissions

reduction tests included two separate analyses:

C a “build/no-build” test in which areas

had to show that emissions would be

less if all projects in the plan/program

were implemented (the “action” scenario) than if they were not implemented (the “baseline” scenario);4

 and

C a “less-than-1990” test in which areas

had to show that emissions in the action scenario would be lower than

1990 emission levels.5

Because PM10 modeling techniques were not

yet well developed, PM10 conformity determinations under the interim guidance could be

accomplished using qualitative assessment methods proposed by the MPO and jointly approved

by US DOT and EPA. The interim guidance

also included a list of specific project types that

the federal agencies agreed would be “exempt.”

Consequently, they could move toward imple4Projects included in the baseline scenario included all in-place regionally significant highway and transit facilities, services and activities and all on-going

transportation demand management (TDM) and transportation system management (TSM) activities. The

action scenario included all projects in the baseline

scenario plus all new regionally significant projects,

including transportation control measures (TCMs) and

non-federal regionally significant projects that would

be implemented by the analysis year.

5The interim guidance required emissions tests for

CO in CO areas and VOCs (but not NOx) in ozone

areas. The less-than-1990 test was not explicitly

spelled out in the interim guidance, but was clarified as

being an implicit requirement of the interim guidance

in a U.S. DOT memo entitled “Further Guidance on

Conformity Determinations” from the Director, Office

of Environment and Planning to the Regional FHWA

Administrators and the Federal Lands Highway

Program Administrator (dated July 27, 1992).
Chapter 2: Purposes and Requirements of Transportation Conformity 19

mentation even if they came from a nonconforming transportation plan/program.

The 1993 Conformity Rule

The CAAA required that EPA, with DOT

concurrence, promulgate the federal conformity regulations before the end of 1991. But

development of the rule proved much more

time consuming than the framers of the statute

had anticipated. Following issuance of the

conformity guidance in June 1991, EPA and

DOT negotiated for more than a year on how

to operationalize the full statutory

requirements. The Notice of Proposed Rulemaking (NPRM),6

 published on January 11,

1993, just as the Bush Administration was

leaving office, generated sharp criticism from

both the transportation and environmental

stakeholders. Senior career officials in both

agencies, eventually joined by policy officials

from the new Clinton team, managed extensive

consultations with stakeholder representatives,

as well as further interagency negotiations, to

develop the final version of the rule, which

was not published until November 24, 1993.7

The 1993 conformity regulations established performance measures and procedural

requirements, specified penalties designed to

motivate compliance, and indicated the circumstances under which the penalties would

be applied.8 It also laid out an implementation

schedule, with varying conformity requirements in each phase:

C The Interim Phase II began 30 days

after publication of the rule (December

27, 1993) and ended with an area’s

submission of a control strategy SIP

for a particular pollutant (i.e., a SIP

with an emission budget, such as the

15% VOC reduction SIP or an attainment demonstration).

C The Transitional Period began with an

area’s submission of a control strategy

SIP and ended when EPA took final

action on the SIP (e.g., an approval,

disapproval, or finding of incompleteness).

C TheControl Strategy Period began for

an area when EPA approved its control strategy SIP and ended when the

area could demonstrate that its emissions had been reduced to meet federal

air quality standards. (This occurred

when EPA approved the area’s

redesignation request, including both a

demonstration that the area had

6Environmental Protection Agency, Criteria and

Procedures for Determining Conformity to State or

Federal Implementation Plans of Transportation

Plans, Programs, and Projects Funded or Approved

Under Title 23 U.S.C. or Federal Transit Act, 40 CFR

Part 51 (58 FR 3768), January 11, 1993.

7Environmental Protection Agency, Air Quality:

Transportation Plans, Programs, and Projects; Federal or State Implementation Plan Conformity; Rule,

40 CFR Parts 51 and 93 (58 FR 62188), 24 November

1993.

8As described below, the 1993 conformity rule has

since been amended three times to simplify some of its

provisions and to increase implementation flexibility.

See Environmental Protection Agency, Transportation

Conformity Rule Amendments: Transition to the

Control Strategy Period, 40 CFR 51 and 93 (60 FR

40098), 7 April, 1995; Transportation Conformity

Rule Amendments: Miscellaneous Revisions, 40 CFR

51 and 93 (60 FR 57179), 14 November, 1995; and

Transportation Conformity Rule Amendments: Flexibility and Streamlining, 40 CFR 51 and 93 (62 FR

43780), 15 August, 1997.
Chapter 2: Purposes and Requirements of Transportation Conformity 20

attained the NAAQS and a maintenance plan that set forth strategies to

sustain compliance for ten years).

C The Maintenance Period began with

approval of the maintenance plan and

continued for 20 years. (The maintenance plan covered a ten-year period, at the end of which another tenyear maintenance plan would be written to outline strategies to preserve the

standard to the end of the 20-year

maintenance period.)

Performance Standards

To ensure that transportation plans, programs, and projects conformed to SIP commitments to meet the national air quality standards, the 1993 conformity rule maintained the

emission reduction tests found in the interim

guidance and added other analytic requirements:

C PM10 areas, previously required only to

perform a qualitative analysis, were

now required to complete a quantitative analysis of PM10 and its precursors (VOCs and/or NOx if they

contributed significantly to PM10 problems), using either the build/no-build

test or the less-than-1990 test.

C Ozone areas, which had been required

to perform the emission reduction tests

(the build/no-build and less-than-1990

tests) only for VOCs under the interim

guidance, were now also required to

perform both emission reduction tests

for NOx (as a precursor of ozone).

C A new emission test, the “budget test,”

which makes a direct comparison

between the SIP mobile source budgets and the emissions modeled from

the transportation network (for all

pollutants and/or their precursors) was

also added by the 1993 conformity

rule.

According to the regulations, for any particular pollutant for which an area was not in

attainment of the NAAQS, emission reduction

tests were required until the end of the Transitional Period. The budget test did not begin

until the onset of the Transitional Period, when

a SIP with a mobile source budget was

submitted.9 Thus, during the Transitional

Period, both the emission reduction tests and

the budget test were required. Not until the

beginning of the Control Strategy Period were

the emission reduction tests dropped, allowing

the use of only the budget test. (As will be

discussed below, this testing protocol was

simplified through amendments to the conformity rule in 1997.)

In any conformity determination, all required emission tests were to be applied to

several analysis years. The first analysis year

was the first milestone year in the applicable

SIP – 1995 in CO areas and 1996 in ozone

areas.10 The second analysis year was either

9The Transitional Period could start at different

times for different pollutants, depending on the due

dates for control strategy SIP submissions for each pollutant. Areas in violation of the NAAQS for more

than one pollutant could therefore simultaneously be in

different conformity periods for different pollutants.

10SIP milestone years are ones in which specific

emissions levels are to be achieved. Thus, in ozone ar-
Chapter 2: Purposes and Requirements of Transportation Conformity 21

the attainment year or, if the attainment year

was the same as the first analysis year or earlier, five years after the first analysis year. The

last analysis year was the final horizon year of

the 20-year transportation plan.11 In between,

additional analysis years had to be selected so

that no two analysis years were more than ten

years apart. Thus, to perform the conformity

analysis, a nonattainment area would complete

all required emission tests for each analysis

year. Nonattainment areas that were out of

compliance for more than one pollutant had to

complete these tests for each pollutant and/or

its precursors.

Procedural Requirements

In addition to the performance standards,

the 1993 conformity rule established a comprehensive set of procedural requirements.

These were intended not only to standardize

the analytic techniques used for conformity determinations, but also to enhance communication and coordination among the agencies

involved with conformity and to ensure implementation of transportation plans/programs

that have air quality benefits. In major nonattainment areas, the rule required the use of

computer simulation models to analyze the

transportation system. Specifically, by January

1, 1995, CO areas and ozone areas classified

serious and above had to use network-based

transportation demand models with certain

specific attributes. As part of the modeling

protocol, the conformity rule required the use

of the most recent planning assumptions

available – e.g., current estimates of population, employment, travel, congestion, transit

service, and TCM implementation. In addition, the rule called for use of the most recent

version of the motor vehicle emission model

and specified the frequency with which

conformity determinations must be made.

The 1993 rule required interagency consultation on conformity determinations, but,

within broad guidelines, allowed each state to

craft customized procedures to reflect its own

institutional arrangements for transportation

and air quality planning. These were to include a delineation of the roles and procedures

to be undertaken by MPOs, the state DOT,

state and local air quality agencies, US DOT,

and EPA before making conformity determinations and developing SIPs. In addition,

the consultation procedures were supposed to

establish guidelines for various conformity

processes, such as selecting transportation

models, deciding whether projects were

exempt or regionally significant, and determining whether TCMs were being funded and

implemented. 

Three other conformity provisions – regarding TCM implementation, fiscal constraint, and exempt projects – sought to ensure

implementation of transportation projects that

benefit air quality. The first was a requirement

that TCMs included in a SIP be implemented

eas, the first milestone year was 1996, when 15% reductions in VOCs were required (unless an attainment

demonstration was submitted first). Subsequent milestones occur every three years thereafter as rate-ofprogress reductions were required.

11Horizon years are those for which the transportation plan describes the envisioned transportation system and documents and quantifies the demographic

and employment factors that influence expected transportation demand. The first horizon year is generally

ten years after the base year and the final horizon year

is the last year in the transportation plan.
Chapter 2: Purposes and Requirements of Transportation Conformity 22

in timely fashion. If a TCM was not being

implemented on time, the MPO had to

determine what obstacles existed, identify the

steps being taken to alleviate the problem, and

ensure that priority was being given to funding

the TCM. Conformity was also made

contingent on fulfilling a provision of ISTEA

requiring transportation plans and programs to

be fiscally constrained – i.e., they could

include only projects that reasonably expected

funding. Historically, transportation plans and

programs listed many more projects than could

be afforded. Although TCMs were included,

they were frequently not implemented because

the responsible agencies chose to spend

available funds on other projects. In addition,

the 1993 conformity rule repeated the categorization of exempt projects (which originated in

the interim guidance).12 This provision allowed

certain transit and air quality beneficial

projects – such as ride-sharing and bike and

pedestrian facilities – to move forward even if

the area could not pass the conformity tests.

Penalties and Penalty Triggers

What made the conformity regulations

compelling to transportation agencies – and

potentially threatening – was that failure to fulfill these conformity requirements by specified

deadlines would prevent programmed transportation projects that were not “grandfathered” (see below) from advancing through

the design and construction process and,

ultimately, lead to withholding of federal

transportation funds.

Penalties under the 1993 conformity rule

take the form of a conformity “freeze”13 or a

conformity “lapse.” 

C During a freeze, no new transportation

plans or programs can be approved,

and no projects can be added to

existing plans/programs. However,

during a freeze, projects from the first

three years of previously conformed

plans/programs can still be advanced –

i.e., reviewed under NEPA or funded

for detailed design or construction.

C During a lapse, no new project-level

conformity determinations can be

made. Because the ISTEA metropolitan planning rules require that only

projects from a conforming plan/program can be funded, a conformity

lapse halts the flow of federal money

to any new projects. However, projects can continue to be funded if they

12The 1993 conformity rule established four categories of exempt projects, which include: (1) Safety

projects, such as railroad/highway crossing, hazard

elimination programs, shoulder improvements, guardrails, median barriers, crash cushions and skid treatments; (2) Mass Transit projects, such as operating assistance to transit agencies, purchase of support vehicles, rehabilitation of transit vehicles, construction or

renovation of signal systems and purchase of new

buses and rail cars; (3) Air Quality projects, such as

ride-sharing and van-pooling promotion activities at

current levels and bicycle and pedestrian facilities; and

(4) Other, such as noise attenuation, advance land acquisitions and acquisition of scenic easements.

13The term “freeze” did not actually appear in the

regulations until the 1997 amendments (see below).

However, it was widely used to denote the the 1993

rule provisions with which it is associated here.
Chapter 2: Purposes and Requirements of Transportation Conformity 23

are exempt or if they are “grandfathered” (i.e., come from a conforming plan and program, have been found

to conform at the project level, have

completed the NEPA process as it

applies to transportation, and have not

changed significantly in design and

scope). Grandfathered projects are

allowed to continue during a lapse

because they have already gone

through the air quality analysis and

been shown not to increase regional

emissions.

The conditions under which conformity

could freeze or lapse depended on specific

“triggers” associated with transportation and

SIP planning deadlines or inability to pass the

conformity tests. The conformity triggers

connected to transportation planning deadlines

were fairly simple and straightforward.

Conformity lapsed if the transportation plan or

program was not updated and conformity redetermined at least every three years. Also,

any plan revision required a TIP update and

conformity re-determination within six months,

unless the plan merely added or deleted

exempt projects.

Conformity triggers associated with SIP

planning were more varied, relating both to

adoption of new SIPs and to EPA disapproval

of previously submitted SIPs. Conformity of

existing transportation plans had to be initially

determined within 18 months of the

publication of the 1993 conformity rule.

Subsequently, conformity had to be determined within 18 months of approval of any

new SIP that established or revised a mobile

source emission budget, or added, deleted, or

changed a TCM. During the transitional

period, a conformity determination on plans

and programs had to be made within one year

of a control strategy SIP due date.

In addition, the 1993 rule included a number of triggers tied to SIP “failures”:

C If a SIP was not submitted, or was

found incomplete, conformity was first

frozen 120 days after the SIP due date

and lapsed 12 months after the SIP due

date.

C If a SIP was disapproved, conformity

lapsed 120 days after the disapproval,

unless the disapproval contained a

“protective finding.” EPA ccould give

a protective finding either to an incomplete or disapproved SIP. A protective finding was granted if EPA determined that the SIP submission

would have been approvable or complete if all committed measures had

been submitted in enforceable form

(i.e., with legally binding implementing

regulations). Under a protective finding, the area would be allowed an

additional 12 months after the finding

to complete the SIP before conformity

would lapse.

In all cases of SIP failure, a conformity

freeze or lapse was based solely on the status

of the SIP, which might or might not have anything directly to do with mobile sources.

Moreover, the penalty was imposed irrespective of the area’s ability to meet other procedural or analytic requirements of the conformity rule. EPA developed the SIP failure

triggers because it believed that, in the prolonged absence of an acceptable control strategy SIP, the CAAA required nonattainment

areas to refrain from advancing transportation
Chapter 2: Purposes and Requirements of Transportation Conformity 24

projects that could increase emissions.14

Amendments to the 1993 Conformity Rule

The first year of implementation of the

1993 conformity procedures concluded with a

dramatic change in national political power.

By early 1995, an aggressive new Republican

Congressional majority, swept into office by

the national elections of November 1994, was

looking critically at all federal regulatory

policies. At the same time, many state officials

vocally criticized the 1993 regulations. They

perceived cumbersome procedural

requirements, models too crude to be used for

critical regulatory purposes, and the looming

possibility of widespread interruptions of

federal transportation funding as a result of

conformity lapses, which appeared likely to

result primarily from missed Clean Air Act

deadlines. These events placed conformity in

a national spotlight. EPA, responding to

stakeholder criticism but preserving the basic

framework of the 1993 regulations, made a

series of modifications to provide

nonattainment areas more time for compliance

and make the requirements more flexible.

Three sets of amendments were eventually

issued between February 1995 and August

1997.

The August 1995 Amendments

The most immediate implementation issue

in late 1994 was pressure on states to complete SIP requirements before conformity

lapsed as a result of a SIP failure. The CAAA

of 1990 had established two types of mandatory sanctions of which the cutoff of state

transportation funds was seen as the more

severe. EPA was obligated to impose this

highway sanction two years after the failure of

states to comply with certain provisions of the

law, including SIP failures. But the 1993 conformity regulations, in effect, imposed the

transportation funding sanction under an accelerated time schedule. For example, many

areas whose 15% VOC reduction SIPs had

been designated “incomplete with a protective

finding,” pending formal adoption of state

regulations, were facing conformity lapses at

the end of 1994, even though they would not

have been subject to highway sanctions for

another year. In November 1994, moreover,

states were required to submit ozone

attainment demonstrations for moderate or

above ozone nonattainment areas and 3% rateof-progress (ROP) plans for serious and above

ozone areas. If these submissions were not

completed on time, areas would face a conformity lapse after only 120 days. But many

were having difficulty putting in place the air

quality dispersion modeling capacity required

for these SIPs, and EPA had not resolved data

and regulatory uncertainties about interstate

ozone transport.

State transportation and environmental

policy officials, convened through the National

Governors Association to seek consensus on

how these issues should be addressed, argued

that imposing conformity-triggered “highway

sanctions” more quickly than could be done

under the mandatory sanctions provision of the

14Environmental Protection Agency, Air Quality:

Transportation Plans, Programs, and Projects; Federal or State Implementation Plan Conformity; Rule,

58 Federal Register 62192 (24 November 1993).
Chapter 2: Purposes and Requirements of Transportation Conformity 25

Clean Air Act was inconsistent with

Congressional intent, especially when EPA

was in part responsible for delays in fulfilling

the Act’s requirements.

EPA acted quickly to grant temporary relief to the substantial number of areas facing

imminent conformity lapses. In February

1995, the agency amended the 1993 rule to increase the time period before conformity

lapsed for certain types of SIP failures, effectively aligning the timing of these lapses with

the mandatory CAAA highway funding sanctions.15 Under these amendments, areas with

certain types of SIP failures were no longer

subject to the conformity lapse and were allowed two years after the finding to correct

the SIP before conformity lapsed. The affected SIP failures were: 

C incomplete 15% SIP with a protective

finding, 

C incomplete ozone attainment demonstration or 3% ROP SIP, 

C failure to submit an ozone attainment

demonstration or 3% ROP SIP, 

C disapproval with a protective finding

for any control strategy SIP for any

pollutant. 

The amendments, however, retained a conformity freeze and did not align the lapse dates

with the CAAA sanctions dates for certain

other types of SIP failures, specifically: 

C a failure to submit a 15% SIP or an incomplete 15% SIP without a protective finding;

C a failure to submit or an incomplete attainment demonstration for CO, PM10

or NO2; or

C a disapproval of any control strategy

SIP without a protective finding. 

Because the amendments dealt only with SIP

failures, areas that had a complete or approved

control strategy SIP were still required to

fulfill the conformity requirements within one

year of the SIP deadline.

National Highway System

Designation Act of 1995

Although the 1993 conformity regulations

had specified that conformity applied only to

nonattainment and maintenance areas, environmental groups had challenged this interpretation of the CAAA of 1990. They successfully

argued in litigation that conformity should also

be required in attainment areas so that they

could anticipate transportation emission problems that might subsequently produce violations of the national ambient air quality standards. Congress pre-empted that legal victory

in November 1995, however, with a provision

in the National Highway System Designation

Act stating that conformity was required only

in nonattainment and maintenance areas.

The November 1995 Amendments

Shortly after the interim final rule for the first

amendments took effect, areas with ozone

attainment demonstration problems gained fur15The ther relief. In March, 1995, EPA Administrator February interim final rule, effective immediately, became final in August 1995.
Chapter 2: Purposes and Requirements of Transportation Conformity 26

Mary Nichols announced a new approach to

development of ozone attainment demonstrations. It phased and delayed the attainment demonstration submission dates, allowing areas more

time to study ozone transport issues and come to

a regional consensus on how to deal with them.

It also postponed the threat of conformity lapses

due to attainment demonstration failures.

Although many areas avoided lapses

through the first conformity amendments and

the attainment demonstration delays, stakeholder criticisms of the conformity rule continued.

In late March, the National Governors

Association brought state transportation and

environmental officials together with EPA and

US DOT managers to outline a variety of

conformity issues they wanted addressed. The

state representatives pushed EPA to align the

lapse dates for SIP failures that were not

covered by the first amendments with CAAA

highway sanction dates. State officials also

advocated making the regulations less

cumbersome and more flexible. They sharply

questioned the value of the build/no-build test

once a SIP budget had been submitted.

Another concern was the inability of areas to

adopt non-federally funded projects during a

conformity lapse. States also wished to have

a mechanism in the conformity rule that would

allow non-exempt projects to be added to

plans/programs without a full-scale regional

analysis. Of concern to some states was the

burden placed on rural nonattainment areas by

a lack of comprehensive transportation

planning and modeling capacity, which made it

difficult to link specific transportation projects

to regional emissions impacts. States also

sought greater flexibility in making TCM

substitutions in SIPs and pointed out the need

for an easier way in which to change SIP

budgets to reflect updated models and/or

assumptions. These issues were discussed in

greater detail in April at a national

stakeholders meeting, including the federal

agencies, state DOTs, MPOs, air agencies, and

environmental advocacy groups.

In responding to these concerns, EPA dealt

again with the most pressing issues and held

the more difficult and less time sensitive for

later deliberation. The second package of

amendments to the 1993 conformity rule (proposed in August 1995 and published as a final

rule in November 1995) included the following

provisions:

C Conformity lapses were aligned with

CAAA highway sanctions for some of

the SIP failures not covered by the first

amendments: 

C failure to submit or an incomplete 15% SIP without a protective finding and 

C failure to submit or an incomplete CO, PM10, or NO2

 attainment demonstration. 

C The grace period during which areas

were required to make a conformity

determination after the submission of a

control strategy SIP was extended

from 12 to 18 months. 

C SIP TCMs were allowed to proceed

during a conformity lapse.
Chapter 2: Purposes and Requirements of Transportation Conformity 27

The August 1997 Amendments

Further changes took two more years of

consultation and negotiation. The third amendments to the 1993 conformity rule, initially

proposed in July 1996 and published in final

form in August 1997, dealt with several issues

that had been previously raised by stakeholders. The most important provisions

simplified the emission test requirements: 

C Areas were allowed to drop the emission reduction tests (build/no-build and

less-than-1990) and use the budget test

within 45 days of a SIP budget

submission.

16 (Previously both the

emission reduction tests and the budget test were required until the budget

was approved by EPA.) This significantly simplified the testing protocol and eliminated several conformity phases that had previously governed the application of emission tests.

C Rural nonattainment or maintenance

areas were given the option of choosing the budget test, the emissions reduction tests (build/no-build and/or

less-than-1990 test) or dispersion

modeling to demonstrate conformity in

the years not addressed by the SIP.

The 1997 amendments also made a number

of changes to give areas greater flexibility in

applying the conformity requirements:

C In areas with a disapproved SIP without a protective finding, the transportation plan or TIP would be frozen (instead of lapsing) 120 days after the

disapproval.

C During a conformity lapse, non-federal

projects could be implemented if they

were included in the first three years of

the most recent plan/program

conformity determination.

C Traffic signalization projects did not

have to come from a conforming

plan/TIP in order to advance, but the

emissions associated with these projects had to be included in the next regional analysis.17

C The transportation network modeling

requirements were streamlined.

However, the 1997 amendments to the conformity rule did not address the issue of flexibility for transportation control measures,

which had concerned a number of states, because EPA believed that TCM substitutions

were already possible under existing policies

for SIPs.

16If a previously approved budget existed, that budget continued to apply for the years it covered.17This provision reflected a Clean Air Act Amendment enacted by Congress in September 1996.
LINKING TRANSPORTATION AND AIR QUALITY PLANNING:

IMPLEMENTATION OF THE 

TRANSPORTATION CONFORMITY REGULATIONS 

IN 15 NONATTAINMENT AREAS

Arnold M. Howitt and Elizabeth M. Moore

Taubman Center for State and Local Government

John F. Kennedy School of Government

Harvard University

March 1999

A Report to the

U.S. Environmental Protection Agency

and the

Federal Highway Administration,

U.S. Department of Transportation

Publication Number

EPA420-R-99-011

CHAPTER 3: IMPLEMENTING THE 

TRANSPORTATION CONFORMITY REQUIREMENTS
Chapter 3

IMPLEMENTING THE TRANSPORTATION

CONFORMITY REQUIREMENTS

The 1993 transportation conformity regulations established a set of technical and procedural requirements, described in Chapter 2,

that had to be satisfied in order to demonstrate

conformity. Each of the 15 study sites

experienced at least some difficulty with these

requirements, which the remainder of this

chapter describes. This analysis emphasizes

the problems encountered as conformity was

implemented.1 Chapters 4 and 5 explore more

broadly the impacts that the conformity process had on transportation and air quality planning.

The problems encountered implementing

conformity in the study sites, summarized in

Table 3-1 by study site, are grouped in six

categories:

• Emission tests: passing the emission

budget and build/no-build tests,

• Modeling procedures: fulfilling the

transportation modeling requirements,

• TCM implementation: demonstrating

timely implementation of those

transportation control measures committed to in control strategy SIPs and

maintenance plans,

• Fiscal constraint: showing that the

transportation plan and program meet

the ISTEA fiscal constraint requirement,

• SIP failure: triggering conformity

problems because of problems with

SIP submissions, and

• Human error: experiencing conformity problems because of procedural

confusion and/or data analysis mistakes.

As will be discussed, the nature and consequences of these problems for the transportation planning process and air quality regulation varied significantly. In applying the specific emission tests of the 1993 regulations,

five study areas encountered significant

difficulties with the budget tests, which continue to pose serious problems for Atlanta,

Charlotte, and Houston. The build/no-build

test was problematic for even more areas, but

the difficulties were less severe – and, because

this requirement was substantially altered by

the 1997 conformity amendments, the problem

has become moot in most areas. No study

area reported difficulty with the less-than-1990

test.

The other conformity requirements were

generally less problematic than the emission

tests. While a number of study sites had some

difficulties gearing up for the network modeling requirements of the 1993 regulations,

only New York City and Chicago faced

serious conformity delays as a result.

1As noted in Chapter 1, although a full assessment

of the technical dimension of conformity modeling was

beyond the scope of the research, the project sought to

examine the technical issues in the larger context of

the institutional relationships involved.
29

Table 3-1

Types of Conformity Problems by Nonattainment Area

Nonattainment

Area

Emission

Budget Test

Emission Build/

No-Build Test

Modeling

Requirements

Timely TCM

Implementation 

Fiscal 

Constraint

SIP 

Failures

Human 

Error

Atlanta X X**

Baltimore X* X

Boston X X X

Charlotte X X

Chicago X X

Denver X X

Houston X X X X**

Milwaukee X*

New Jersey X*

New York X* X

Philadelphia X*

Phoenix X X

Portland X

Salt Lake X X

San Francisco X

 * Although these areas have reported very close calls passing the build/no-build test, particularly for NOx, they have not necessarily had to make any

adjustments and have not experienced conformity delays as a result.

 ** These are technical SIP failures that had no discernable impact on local planning.
Chapter 3: Implementing the Transportation Conformity Requirements 30

The fiscal constraint requirement posed no serious problems for any areas, although Boston

experienced a brief conformity delay because

of this test. Initially, the provisions of the

1993 rule regarding SIP failures caused

problems for a few areas; but the 1995

conformity amendments alleviated this issue.

Within the study time frame, only Salt Lake

City suffered a conformity freeze or lapse

because of SIP failure.

Table 3-2 identifies for each study site the

conformity problems encountered and their

impacts. In the following pages, the extent to

which study sites experienced difficulty with

each category of conformity problem is

examined in greater depth.

Passing the Emission Tests

The 1993 conformity rule requires areas to

demonstrate that emissions from transportation plans/programs will remain within the

allowable cap set by the SIP budget (the emission budget test) and that transportation plans

will contribute to the overall reduction of

pollution (the build/no-build and the lessthan-1990 tests).

Budget Test 

Difficulty passing the budget test has proven to be the most serious type of conformity

problem, causing most of the lapses experienced in the study areas. Five of the study areas have experienced difficulties with the budget tests. Four of them – Atlanta, Charlotte,

Houston, Salt Lake City – had difficulty

passing the ozone budget tests; and two areas

– Denver and Salt Lake City – had trouble

with PM10 budgets. Only Houston was able to

avoid a lapse during the study period. As a

result, budget test problems have had the

largest impact on transportation and air quality

planning (as will be discussed in greater depth

in Chapters 4 and 5).

ATLANTA. Ozone budget test difficulties

have led to a conformity lapse and caused a

number of transportation projects to be scaled

back, delayed, or indefinitely postponed. Although the area had little difficulty with

conformity in 1994, the MPO began implementing model and data upgrades in 1995 that

predicted higher emission levels than had been

reflected in the earlier analysis. As a result,

Atlanta barely squeaked through its 1995

budget analysis. 

In 1996, passing the budget test proved

even more problematic. Because the area was

experiencing higher than expected VMT

growth and was slow to implement inspection

and maintenance and reformulated gasoline

programs, its 1999 NOX budget for ozone set

an emissions cap that the area could not meet

in developing a new TIP. ARC, the Atlanta

MPO, and Georgia DOT struggled to develop

strategies that would close the large gap

between allowable and projected emissions.

Ultimately, the northern arc of the Outer Loop

was barred from moving into the TIP, the road

to the massive new Mall of Georgia was scaled

back, and only exempt and grandfathered

projects from the previously conformed 1995

TIP were allowed to move forward.

These problems continued throughout

1997 during which ARC could not develop a
1Milwaukee, New Jersey and Philadelphia are not included in this table because they reported only problems with the build/no-build tests that did not cause a

delay to the conformity determination. 

Table 3-2

Problems Meeting the Conformity Requirements by Nonattainment Area1

Area Problem Impact

Atlanta 1996 - Budget Test (NOx for ozone)

1997 - Budget Test (NOx for ozone)

1996 - Conformity determination could not be completed; MPO advanced only

grandfathered and exempt projects.

1997 - Conformity determination could not be completed. After EPA-DOT

dispute resolved, MPO adopted Interim TIP with only grandfathered and

exempt projects. Conformity lapsed: January 1998.

Baltimore 1995 - Non-implementation of ECO 

1997 - Legislature made I/M voluntary

1995 - MPO developed Regional Commuter Assistance Program to make up for

lost emission reductions from ECO program.

1997 - Governor vetoed voluntary I/M program in part because a non-mandatory program would have caused EPA disapproval of the 15% SIP, with

consequences for conformity.

Boston 1994 - Data Entry Error 

1994 - Fiscal Constraint

1995 - Build/no-build Test (for CO, VOC and

NOx) 

1994 - Conformity determination delayed for 2-3 months until problem 

discovered.

1994 - Conformity approval delayed while STIP fiscal constraint resolved.

1995 - MPO added CMAQ project to TIP for off-model analysis.

Charlotte 1994 - Budget Test (NOx and VOC for

ozone)

1996 - Budget Test (NOx and VOC for

ozone)

1994 - Conformity analysis completed by creating budget reconciliation

methodology.

1996 - Conformity determination could not be completed. MPO advanced only

grandfathered and exempt projects. Conformity lapsed: January 1997,

with no resolution by early 1998.

Chicago 1994 - Build/no-build Test (NOx for ozone)

1994 - Network model assumptions 

questioned

1995 - Network model enhancements not in

place

1994 - MPO completed off-model analysis for replacement buses.

1994 - Conformity determination delayed while MPO justified its low VMT

estimates.

1995 - MPO advanced only grandfathered and exempt projects.
Area Problem Impact

Denver 1994 - Budget Test (PM10)

1996 - Budget Test (PM10 & NOx for PM10)

1994 - Conformity lapsed: November 1994 for approximately one year, until

September 1995. Amended PM10 budgets.

1996 - MPO negotiated local agreements for sanding and sweeping measures,

and air agency tightened I/M NOx test for future years.

Houston 1994 - Build/no-build Test (NOx for ozone)

1994 - Budget Test (VOC for ozone)

1997 - Budget Test (VOC for ozone)

1994 - Conformity delayed while waiting for a temporary NOx waiver.

1994 - MPO spread large highway projects out over several years and scaled

back the Grand Parkway.

1997 - Air agency made technical corrections to submitted VOC budget.

New York 1995 - No network based transportation 

demand model

1996 - No network based transportation 

demand model

1995 - MPO advanced only grandfathered and exempt projects.

1996 - MPO received extension of 1994 TIP to advance grandfathered and

exempt projects. In 1997, a new interim network model was approved,

new budgets were submitted, and conformity determined.

Phoenix 1994 - Build/no-build Test (NOx for ozone)

1995 - Network model enhancements not

complete

1994 - Conformity determination delayed several months until NOx waiver

approved; MPO advanced only grandfathered and exempt projects

1995 - Conformity determination delayed until MPO completed model 

enhancements

Portland 1994 - Human Error (incorrect assumptions

used in conformity analysis)

1994 - Conformity lapsed for one year; MPO advanced only grandfathered and

exempt projects

Salt Lake 1993 - Incomplete SIP without protective

finding.

1994 - Budget Test (NOx for PM10)

1995 - Budget Test (NOx for ozone)

1993 - Conformity frozen until SIP found complete in 1994.

1994 - Conformity lapsed November 1994 to October 1995; MPO received

permission from EPA to use MOBILE 4 for conformity analysis of NOx

for PM10.

1995 - Air agency added ten years to the ozone maintenance plan.

San Francisco 1996 - Timely Implementation of TCMs 

questioned 

1996 - MPO made more detailed accounting of TCM problems and steps to 

alleviate them.

32
Chapter 3: Implementing the Transportation Conformity Requirements 33

new long-range plan that conformed. In

August 1997, FHWA granted a six-month TIP

extension, during which a controversy over

grandfathering projects surfaced. Not able to

develop a full conforming TIP, the MPO

drafted an interim TIP (ITIP) that contained

only TCMs written into SIPs that had received

EPA approval, as well as grandfathered and

exempt projects from the 1995 regional transportation plan update. Several dozen projects

that ARC originally wanted to regard as

grandfathered were not ultimately included in

the ITIP because FHWA felt they could not

meet the applicable NEPA requirements; EPA

simultaneously reviewed the NEPA

documents. FHWA’s regional office was then

prepared to approve the ITIP, but EPA’s

regional office raised concerns about several of

the remaining grandfathered projects in the

ITIP.

This led to sharp policy disagreements

among the federal agencies. Even though the

1995 plan had received a conformity determination, EPA’s regional office argued that the

conformity analysis had not satisfied all of the

applicable requirements of the conformity rule.

EPA therefore believed that the disputed

projects should not be grandfathered because

they would substantially increase highway capacity, worsening air quality problems. Staff

from the White House Council on Environmental Quality ultimately brokered a regionallevel agreement among EPA, FHWA, and

FTA that allowed five of six disputed projects

to move forward in the ITIP, with two of these

limited to planning and design. ARC removed

the sixth project from the ITIP. The EPAFHWA-FTA agreement also established dates

by which the Atlanta area should complete a

conforming long-range plan and an ozone

attainment demonstration.2 Conformity lapsed

in Atlanta on January 17, 1998.

CHARLOTTE. Like Atlanta, Charlotte has

also experienced recurring problems with the

ozone budget tests. Initially, these seemed

mainly to be procedural difficulties, but subsequent problems led to a prolonged conformity lapse and the delay of some transportation

projects. In 1993, the state air agency chose

to request redesignation to attainment for

Charlotte as a moderate ozone area that had

not had recent air quality violations; the area

prepared a maintenance plan rather than submit a 15% VOC reduction SIP. In 1994, during its first conformity determination under the

1993 conformity rule, the area found that

future VOC and NOx emission projections

derived from the transportation plan were

higher than the emission budgets in the ozone

maintenance plan. Planners at the state air

agency believed that the higher emissions in

the transportation plan were due not to an

actual increase in pollution, but to the

difference between the methods used to calculate VMT in the base year for the emission

budgets (using HPMS and other data) and

those used to develop the new transportation

plan (using the MPO’s travel demand models).

To rectify this problem, the area developed a

reconciliation methodology that applied a

corrections factor to the base-year inventories

to make them comparable to the 1990

emission levels in the transportation

2

In addition, the agreement recognized the need

for national-level staff of EPA, FHWA, and FTA to

develop a national memorandum of understanding or

make changes in the conformity regulations to ensure

proper use of the grandfathering provision, particularly

to see that it was not used to evade the consequences of

a conformity lapse.
Chapter 3: Implementing the Transportation Conformity Requirements 34

plan. The air agency argued that once the

difference in the base-year VMT calculations

was reconciled, the area should conform if the

emissions growth rate in the transportation

plan stayed below the growth rate in the

maintenance plan. Although the area passed

conformity in 1994 using this methodology,

EPA subsequently required that the area develop a technique that adjusted base-year

VMT to match the SIP’s base year emissions

inventory rather than vice versa, as any adjustments applied to the budget would require

a SIP amendment. The state and MPO subsequently accomplished this.

Problems with conformity did not surface

again in Charlotte until 1996, when the area,

experiencing substantial increases in VMT, began to have serious trouble passing the ozone

budget tests for NOx and VOC. In 1995, the

MPO had decided that a conformity analysis

was not required since the projects in the new

TIP came from a conforming plan and had not

undergone any major changes. Later in the

year, however, the air agency discovered an

error in its emission budget calculations.

When the corrected budget was used in the

conformity analysis for a proposed 1996 TIP,

the results showed a substantial exceedance of

the emission budget. Although much effort

went into finding a solution – with the MPO,

state DOT, and state air agency staff

discussing many potential solutions – the budget test disparity could not be resolved, and

the TIP could not be adopted. During 1996,

the agencies tried unsuccessfully to develop a

required transportation plan update that could

meet conformity requirements. Conformity

therefore lapsed in January 1997, and this

lapse had not yet been resolved by early 1998.

Although numerous grandfathered and exempt

projects continued to move forward during the

lapse, three new transportation projects were

held up.

HOUSTON. The budget test for ozone has

also posed difficulties for Houston. Although

at the end of the study period, the area had

been able to resolve its conformity problems

without a lapse, it was uncertain how much

longer it would be able to do so. Houston’s

conformity problems began in 1994 when the

area had trouble passing the VOC budget test.

It resolved the problem by postponing some

highway projects and scaling back the massive

Grand Parkway project (although this was

done more to meet fiscal constraint requirements than to pass the emission test). In

1997, Houston again had difficulties when it

ran its first conformity analysis using a 1999

VOC budget, which tightened the emission cap

from the 1996 budget level. Transportation

planners found it difficult to show that

emissions toward the end of the 20-year transportation planning horizon would stay below

1999 levels. This problem was resolved by

making technical corrections to the submitted

(but not yet approved) SIP that recalculated

the budget using VMT estimates from the

travel demand models rather than from HPMS

data.

At the end of the study period, Houston was

anticipating future problems passing the NOx

budget test for ozone. The area had been

granted a temporary NOx waiver in April 1995

that permanently expired at the end of 1997. As

planners looked ahead, they were uncertain how

the area would be able to reduce mobile source

NOx emissions sufficiently to stay within the

emission cap imposed by a NOx budget.
Chapter 3: Implementing the Transportation Conformity Requirements 35

SALT LAKE CITY. The budget test for

ozone also created problems for Salt Lake

City, but this area did not experience a lapse.

Like Charlotte, Salt Lake City had been redesignated to attainment, submitting a maintenance plan rather than a 15% SIP in 1993. In

1994, the area had difficulty demonstrating

that emissions toward the end of the 20-year

transportation planning horizon would stay

below the 2005 NOx budget in the ozone

maintenance plan. To alleviate the problem,

the area added 10 years to the maintenance

plan, establishing budgets to 2015. The extended budgets, which take account of emission reductions from vehicle fleet turnover,

allow NOx emissions (as a precursor of ozone)

to rise after the end of the 10-year maintenance plan without causing violations of the

ozone standard. With higher budgets, the area

passed conformity in 1995 and has not encountered subsequent problems with the conformity emissions tests for ozone.

In addition to its ozone budget problems,

Salt Lake City also had difficulty passing the

NOx budget test for PM10 in 1994. The area’s

PM10 SIP had been developed in the late 1980s

– long before the budget concept or the

conformity procedures had been established in

law. This proved particularly problematic for

NOx (as a precursor of PM10). Although NOx

was not a consideration when the SIP was

written, an implicit NOx budget was derived

from the SIP. Further complicating the NOx

issue was the fact that the NOx budget had

been derived using MOBILE 4, while the

conformity analysis used MOBILE 5, which

calculated much higher NOx emissions for

mobile sources. Unable to make this “apples

and oranges” comparison work for conformity,

the area lapsed in November 1994. Advancing

only grandfathered and exempt projects, the

MPO tried to convince EPA that the budget

problem was not the result of real increases in

emissions but of differences in the way

MOBILE 4 and MOBILE 5 projected NOx

emissions. EPA was eventually persuaded and

has since allowed the Salt Lake City area to

use MOBILE 4 in the conformity analysis for

NOx (as a precursor of PM10, but not of

ozone).3

DENVER. Like Salt Lake City, Denver

lapsed when it tried to test conformity using

budgets that were implicitly derived from a

PM10 SIP that pre-dated the conformity rule.

Denver’s budget problems began in 1994

during the conformity analysis of the 1994

TIP. Transportation planners could not demonstrate that emissions in the final horizon

year of the transportation plan (2015) would

stay below the 1997 PM10 budget of 44 tpd in

the maintenance plan. The area lapsed and

advanced only grandfathered and exempt

projects while it undertook the difficult and

contentious task of amending the PM10 budgets.

Working together, regional transportation

and air quality planners sought a solution that

would allow them to increase the PM10 budget

without jeopardizing the area’s ability to reach

PM10 attainment. Analysis indicated that peak

regional PM10 emissions would be approximately 65 tpd in Denver’s downtown

core in 2015 if the proposed transportation

plan were implemented. Further, the planners

determined that the regional PM10 emissions

3

EPA permitted this practice in a limited number

of PM10 nonattainment areas because the SIP had been

submitted and approved before the 1993 conformity

regulations were finalized.
Chapter 3: Implementing the Transportation Conformity Requirements 36

budget could be raised from 44 to 60 tpd –

without either imposing new controls on

stationary and area sources or causing

violations of the NAAQS. Therefore, they

proposed adopting mitigation measures that

would reduce 2015 emissions to the 60 tpd

level in the Denver core, while allowing the

permissible level of PM10 emissions to rise to

the 60 tpd level in the suburban areas of the

region.4 This proposal provoked months of

controversy and criticism from environmental

and public health advocates regarding the

health effects of increased particulate levels.

The proposed budget increase was approved

for only a three-year period by the state air

agency, allowing the area to conform the plan

and TIP in 1995 but posing the threat of a

recurring conformity problem. The state

legislature subsequently intervened to allow

the budget amendment to apply throughout the

period covered by the SIP. 

In 1996 Denver more briefly experienced

problems passing the budget tests for both

PM10 and NOx (as a precursor of PM10), but

was able to find solutions without sparking a

major controversy or experiencing a lapse. To

do so, the area adopted street sanding and

sweeping agreements at the local level to reduce PM10 emissions and promised future-year

tightening of the standards in inspection and

maintenance tests to pass the NOx budget test.

Build/No-Build Test 

Many areas in the study experienced difficulty with the build/no-build tests – especially

for NOx. In some instances the conformity

determination was slowed or delayed, but in

no case did conformity lapse as a result of the

build/no-build test.

Two study sites – Houston and Phoenix –

realized in 1994 that they would not be able to

pass the NOx build/no-build test. Each applied

for a NOx waiver, which delayed its conformity

determination while the waiver was processed.

Phoenix received a permanent waiver, and

Houston was granted a temporary waiver

pending the results of a study to determine

whether or not the area would benefit from

NOx controls. Houston’s waiver, as noted

above, expired at the end of 1997.

Several other study sites – including Baltimore, Boston, Chicago, Milwaukee, New Jersey, New York, and Philadelphia – have had

varying degrees of difficulty with the build/nobuild test. Some have been able to pass the

NOx build/no-build only by a razor-thin

margin, sometimes by making small adjustments in the initial modeling assumptions.

Some reported tipping the scales through offmodel analysis of CMAQ projects that were

not captured by the network model. Chicago

followed this strategy in 1994, taking credit

for new alternative fuel buses. (It subsequently applied for a NOx

 waiver, which was

granted in 1996.) After similar difficulty in

1995, the Boston MPO developed a way of

handling this type of situation. It routinely

does not claim credit in the regional analysis

for projects such as park-and-ride lots, van4DRCOG was able to quantify its safety margin,

showing how much emissions might rise, and assigned

that budget to mobile sources. In its PM10 SIP, it used

dispersion modeling to determine where violations

would occur in the region and committed to do dispersion modeling in the future to demonstrate conformity.

The SIP also commits DRCOG to adopt additional

control measures if they are needed in the future to

pass conformity tests.
Chapter 3: Implementing the Transportation Conformity Requirements 37

pool programs, or replacement buses. Then, if

build/no-build problems arise, it completes an

off-model analysis of specific projects to demonstrate conformity.

Baltimore faced a potential build-no build

problem that stemmed from state government

resistance to the national Employee Commute

Option program mandate in severe ozone nonattainment areas. Baltimore’s 1994 transportation plan assumed ECO implementation. But

in the face of significant opposition from the

Baltimore business community, which feared

being at a disadvantage to its competitors in

nearby Washington, D.C. (an area not subject

to the ECO mandate), Maryland’s governor

issued an executive order declaring ECO

voluntary; and the legislature eliminated all

program funding.5 When the Baltimore MPO

continued to include ECO in its 1995 conformity analysis, the state air agency expressed

discomfort that the program was nonetheless

credited; and an environmental group questioned the validity of claiming full emission

credit for a voluntary program. The MPO

therefore deleted ECO from the conformity

analysis, replacing it with a regional commuter

assistance program that it pledged to implement in 2005.

Boston and Chicago reported a technicality

in the way the build/no-build analysis is

calculated that made the test highly problematic. Boston cited an example from its 1995

conformity analysis. When planners analyzed

the 1996 milestone year, FY 1996 projects

were in both the “action” scenario and the

“baseline” scenario (because it had already

been conformed in the FY 1995-97 TIP).

Because there had been no other regionally

significant changes, the analysis showed no

decrease in emissions in the “action” scenario,

which is required by the conformity rule. The

Boston MPO resolved this problem by adding

a CMAQ project to the TIP for off-model

analysis. Chicago, as noted above, took credit

for new alternative fuel buses.

Most of the issues with the build/no-build

tests no longer exist with implementation of

the 1997 amendments to the conformity rule,

which allow areas to use only the budget test

for conformity 45 days after a SIP with a budget is submitted.6

 Previously areas were required to continue the build/no-build tests until

submitted budgets were approved by EPA, a

process that can take more than a year.

Less-than-1990 Test

No study site reported problems satisfying

the requirements of the less-than-1990 emission test.

Using the Required Modeling

Techniques

Several areas had conformity problems due

to the conformity rule’s demand for use of a

5Congress subsequently amended the Clean Air

Act to make the ECO program voluntary in the areas

previously required to implement the program.

6

This holds true unless a SIP budget has previously been approved by EPA for all or part of the

time period in question. In that case, the old approved

budget must be used for the time period for which it

was approved until the new budget is approved as a replacement.
Chapter 3: Implementing the Transportation Conformity Requirements 38

network-based transportation demand model

with specific attributes. As noted earlier in this

chapter, New York City experienced the most

difficulty meeting the modeling requirements

as the area had not previously used a network

based model. New York demonstrated

conformity in 1994 using qualitative analysis

and sketch planning techniques, but it did not

have the required network model up and

running by the January 1995 deadline. The

area therefore advanced only exempt and

grandfathered projects in 1995. When the

models were still not in place by 1996, the area

sought and received a third-year extension of

its 1994 TIP, continuing to move forward

exempt and grandfathered projects. The first

generation of network models was finally

operational in 1997, and New York City was

at last able to complete the required

conformity analysis to adopt a new plan and

TIP.

Chicago and Phoenix also experienced

conformity delays while they worked on upgrading network models they already had in

place. Chicago undertook a major overhaul of

its already existing network model. In the

process, CATS had to forgo a conformity analysis in 1995 as the required changes were not

yet in place. The area therefore had to delay

implementation of some projects, advancing

only those that were grandfathered and exempt

until the next conformity cycle. In Phoenix,

the 1995 conformity determination was

delayed – but only briefly – while model

enhancements were completed.

Demonstrating Timely Implementation of SIP TCMs

Of the 15 study sites, only San Francisco

reported any difficulty documenting timely

implementation of SIP TCMs, and this did not

cause any delay in demonstrating conformity.

As part of the settlement of the suit brought by

the Sierra Club Legal Defense Fund and other

environmental advocates against the

Metropolitan Transportation Commission

(MTC), San Francisco was required to incorporate a number of TCMs which dated

back to its 1982 SIP into its ozone maintenance plan. Because a number of these were

imprecisely defined, the Bay Area air agency

and the EPA regional office in 1996

questioned their timely implementation, which

had not been well documented in previous

conformity analyses. In response, MTC

provided a more detailed description of the

TCMs and explained the steps taken to

implement them, which satisfied the air district

and EPA that the conformity requirement was

being met.

Meeting the Fiscal Constraint Requirement

Many study areas indicated that the fiscal

constraint provision of ISTEA, also a conformity requirement, has had significant impact

on transportation plans/programs. Many

MPOs have had to pare down long lists of projects included in earlier plans for which funding could not be reasonably expected. As

previously mentioned, Houston scaled back its

Grand Parkway project to ensure that its longrange plan met ISTEA’s fiscal constraint

requirement. Only Boston and Denver among
Chapter 3: Implementing the Transportation Conformity Requirements 39

the study sites, however, had any problems

completing a conformity determination

because of fiscal constraint problems.

Boston’s problem in 1994 was not directly

a conformity problem but did cause a delay in

concluding the area’s conformity determination. During the approval process of its

FY 1995-97 STIP, FHWA’s Massachusetts

division office cited two fiscal constraint

problems. FHWA believed that the second

year of the STIP (FY 1996) was 100% overprogrammed because it budgeted the sum of

its highway apportionments, plus its unobligated balance. In addition, the state was counting

on money from a bond bill not yet approved by

the legislature to fund a major project during

the first two years of the STIP. FHWA and

FTA therefore deferred approval of the STIP

pending resolution of these issues. This action

effectively put the Boston TIP conformity

determination on hold until the state produced

a financially constrained STIP in March 1995.

Although highway funding was held-up and

TIP conformity could not proceed, this was

not technically a “conformity lapse,” having

been caused by a funding dispute between

FHWA and the state over the STIP.

In 1996, Denver area environmentalists

raised fiscal constraint issues during the conformity process. Arguing that the MPO was

mitigating emissions from the E-470 tollway

project by claiming credit for transit expansion

projects that did not have secure funding, they

threatened to sue on the grounds that the plan

was not adequately fiscally constrained. The

MPO counter-argued that the emission

benefits of the transit projects were so small

that the projects could be totally removed from

the plan without threatening the conformity

determination. Ultimately, no litigation was

filed, and there was no delay in the conformity

determination.

Links to SIP Failures

Under the 1993 conformity rule, certain

types of SIP failures (described in Chapter 2)

can trigger a conformity freeze or lapse, regardless of a satisfactory emission analysis of

the transportation plan or program. Several

examples of this were found in the 15 study

sites.

Initially, areas had one year to submit a

control strategy SIP and have EPA declare it

complete – or else conformity would lapse.

Given myriad challenges during the start-up

phase of CAAA implementation, a number of

areas around the country did not meet this

deadline and therefore experienced conformity

lapses while SIP requirements were completed. Two study areas – Atlanta and Houston – appeared on FHWA’s lapse list during

this period. It appears, however, that any impacts there were quite minimal. When interviewed later, area planners were either unaware of or didn’t remember that a lapse had

occurred.

Subsequently, the February 1995 conformity amendments increased the time for areas to

submit complete SIPs to two years, aligning

the SIP conformity lapse with imposition of

CAAA highway sanctions. Several other

study areas – including Baltimore, Boston,

Milwaukee, New York City, Philadelphia and

Phoenix – were saved from a lapse by this

change.
Chapter 3: Implementing the Transportation Conformity Requirements 40

Salt Lake City had a more serious SIP

“completeness” problem. In 1993 it submitted

an ozone attainment redesignation request,

which EPA subsequently declared incomplete.

Under the 1993 conformity rule, conformity

was, in effect, frozen – that is, beginning 120

days after the finding, no new transportation

plans or programs could be approved and no

projects could be added to existing

plans/programs. The area sued EPA; and as a

result of subsequent negotiations, EPA

declared the submission complete in July 1994,

ending the problem.

Baltimore faced a potential SIP failure

problem in 1997 when the Maryland legislature passed a law that would have made the

state’s I/M program voluntary. This would

have caused the 15% VOC reduction SIP to

be disapproved by EPA. The Governor vetoed this bill at least in part because of the

conformity implications of failing to implement

the required form of I/M. At the end of the

study period, Boston and New Jersey were

also anticipating possible conformity problems

associated with delays in their I/M programs.

Human Error

In the course of interpreting and executing

the analytic and procedural requirements of

conformity, three areas have had problems that

are attributable simply to human error.

Portland is the most dramatic example. In

1994, during the first conformity analysis under the 1993 conformity rule, the MPO had

some difficulty interpreting the build/no-build

requirements. Because it made incorrect

assumptions about which projects should go

into the build and the no-build scenarios, the

conformity determination was invalid. When

this was discovered, the area decided to let

conformity lapse for a year rather than expending the resources to re-do the analysis.

This decision resulted from the realization that

a lapse would not interfere with currently

planned projects, which were either exempt or

grandfathered.

Boston also encountered conformity difficulty due to a human error. In 1994 the area

could not pass the build/no-build tests for

VOC, NOx, or CO due to a calculation error in

a spreadsheet the air agency provided to the

MPO for the conformity analysis. After the

two agencies probed the causes of the conformity problem for a few months, the error

was discovered and corrected.

As mentioned above, the North Carolina

air quality agency made a mistake in the calculation of Charlotte’s NOx

 and VOC budgets

in 1994, which made passing conformity easier

at that time. However, when the error was

corrected, subsequent emission analysis in

1996 – which also took account of changing

conditions – revealed conformity difficulties

that had not been resolved at the conclusion of

the study period.
LINKING TRANSPORTATION AND AIR QUALITY PLANNING:

IMPLEMENTATION OF THE 

TRANSPORTATION CONFORMITY REGULATIONS 

IN 15 NONATTAINMENT AREAS

Arnold M. Howitt and Elizabeth M. Moore

Taubman Center for State and Local Government

John F. Kennedy School of Government

Harvard University

March 1999

A Report to the

U.S. Environmental Protection Agency

and the

Federal Highway Administration,

U.S. Department of Transportation

Publication Number

EPA420-R-99-011

CHAPTER 4: INSTITUTIONAL ROLES IN THE

TRANSPORTATION CONFORMITY PROCESS
Chapter 4

INSTITUTIONAL ROLES IN THE 

TRANSPORTATION CONFORMITY PROCESS

Fulfilling the purposes of conformity depends crucially on creating stronger institutional links between two policy areas – transportation and air quality – that had operated

quite independently of each other prior to

enactment of the CAAA of 1990. 

The previous framework of federal law did

not create effective incentives for collaboration

between the agencies working in the two

policy areas. It required integration between

separately mandated transportation and air

quality planning processes. But it provided

minimal federal financial aid for planning activities, and few penalties were imposed on states

for failing to implement pollution reduction

policies contained in their SIPs. 

As a result, although air quality regulators

could seek pollution reductions from the

transportation sector, they frequently could

not secure the commitment and cooperation of

the transportation agencies in developing

policies to achieve this purpose. Nor could the

regulators assure that state and local elected

officials would actually adopt the policies the

regulators mandated. They could not ensure,

therefore, that the air quality impacts of transportation policies would be taken into account

in decision making, that transportation projects

inconsistent with pollution reduction targets

would not be undertaken, and that promised

projects with air quality benefits would actually be implemented.

Enactment of the CAAA of 1990 and

ISTEA created a new regulatory climate.

Transportation agencies were directed to make

air quality a key goal and were given strong

fiscal incentives for compliance. But the intent

of the conformity regulations and other

provisions of the new laws was not merely to

impose tougher command-and-control regulations. At least as important was establishing a

procedural framework for collaboration among

transportation and air agencies.

For the core regional and state agencies involved – particularly MPOs, state and regional

air agencies, and state DOTs – implementation

of the conformity regulations created

significant stresses, not merely in terms of

what conformity itself required but also in the

context of broader changes stemming from the

CAAA and ISTEA. Even without the conformity requirements, air quality and transportation agencies faced substantial increases in

workload as well as the need to develop new

skills and to build relationships with other

agencies.

This chapter examines this institutional

dimension of conformity. Table 4-1 identifies

the core public agencies concerned with conformity in each study site. The chapter inquires first into how these agencies went about

building the organizational capacity, particularly the technical tools, they needed to

carry out the conformity requirements. Then

it explores the development of interagency

consultation practices, both in terms
Table 4-1

Core Public Agencies in Transportation and Air Quality Planning, by Nonattainment Area

NONATTAINMENT AREAMETROPOLITAN PLANNING ORGANIZATIONSTATE TRANSPORTATION

AGENCY

STATE AIR QUALITY AGENCY LEAD AGENCY FOR

SIP DEVELOPMENT

Atlanta Atlanta Regional

Commission (ARC)

Georgia Department of

Transportation (GDOT)

Georgia Department of Natural

Resources (DNR)

State AQ agency

Baltimore Baltimore Metropolitan

Council (BMC)

Maryland Department of

Transportation (MDOT)

Maryland Department of the

Environment (MDE)

State AQ agency

Boston Boston MPO The Executive Office of

Transportation and

Construction (EOTC)

Massachusetts Department of

Environmental Protection (DEP)

State AQ agency

Charlotte Mecklenburg/Union MPO North Carolina Department of

Transportation (NCDOT)

North Carolina Department of

Environment and Natural

Resources (DENR)

State AQ agency

Chicago Chicago Area

Transportation Study

(CATS)

Illinois Department of

Transportation (IDOT)

Illinois Environmental Protection

Agency (IEPA)

State AQ agency

Denver Denver Regional Council

of Governments

(DRCOG)

Colorado Department of

Transportation (CDOT)

Colorado Department of Public

Health and Environment

(CDPHE)

Regional Air Quality

Council (RAQC)

Houston Houston-Galveston Area

Council (HGAC)

Texas Department of

Transportation (TxDOT)

Texas Natural Resources

Conservation Commission

(TNRCC)

State AQ agency

42
NONATTAINMENT AREA

METROPOLITAN PLANNING ORGANIZATIONSTATE TRANSPORTATION

AGENCY

STATE AIR QUALITY AGENCY LEAD AGENCY FOR

SIP DEVELOPMENT

Milwaukee Southeastern Wisconsin

Regional Planning Commission (SEWRPC)

Wisconsin Department of

Transportation (WisDOT)

Wisconsin Department of

Natural Resources (DNR)

State AQ agency

New York New York Metropolitan

Transportation Council

(NYMTC)

New York State Department of

Transportation (NYSDOT)

New York State Department of

Environmental Conservation

(DEC or EnCon)

State AQ agency

Northern New

Jersey

North Jersey

Transportation Planning

Authority (NJTPA)

New Jersey Department of

Transportation (NJDOT)

New Jersey Department of

Environmental Protection

(NJDEP)

State AQ agency

Philadelphia Delaware Valley

Regional Planning Com.

(DVRPC)

Pennsylvania Department of

Transportation (PennDOT)

Pennsylvania Department of

Environmental Protection (DEP)

State AQ agency

Phoenix Maricopa Association of

Governments (MAG)

Arizona Department of

Transportation (ADOT)

Arizona Department of

Environmental Quality (DEQ)

The MPO

Portland Metropolitan Service

District (Metro)

Oregon Department of

Transportation (ODOT)

Oregon Department of

Environmental Quality (DEQ)

State AQ agency

Salt Lake City Wasatch Front Regional

Council (WFRC)

Utah Department of

Transportation (UDOT)

Utah Department of

Environmental Quality (DEQ)

State AQ agency

San Francisco Metropolitan

Transportation

Commission (MTC)

California Department of

Transportation (Caltrans)

California Environmental

Protection Agency 

(CalEPA)

Joint: Bay Area Air

Quality Mgmt District, 

Assoc. of Bay Area 

Govts, and MTC

43
Chapter 4: Institutional Roles in the Transportation Conformity Process 44

of the “official” process required in conformity

SIPs and the relationships that have emerged

in practice. Then the chapter turns attention to

the role that nongovernmental stakeholders,

particularly environmental advocacy groups,

have played in conformity.

Finally, the chapter inquires whether conformity has had a wider impact by raising the

public profile of transportation and air quality

issues, educating the public, and increasing the

likelihood that senior policy and elected officials would feel compelled to address these

issues.

Building Institutional Capacity

Contextual Conditions

CAAA. The CAAA of 1990 transformed

national regulation of air pollution. In doing

so, it left state governments and regional agencies with numerous new policies to develop

and politically controversial regulations to

draft and adopt (many under tight time deadlines imposed by Congress), as well as with

new on-going tasks to carry out.

For air agencies, conformity was merely

one of several challenges in transportation

competing for attention – and transportation

policy was only part of the sweeping scope

and workload created by the CAAA. Among

other transportation duties, air agency mobile

source staff had to prepare inventories and

forecasts of emissions, develop mobile source

emission control strategies in SIPs, and see

that programs such as enhanced I/M, ECO,

oxygenated and reformulated fuels, and gas

pump vapor recovery were successfully

launched. State transportation departments

and MPOs, for their part, had fewer new tasks

to perform as a result of the new statute; but

they recognized, some more quickly than

others, that the CAAA had potentially profound implications for their policies, operations, and funding streams. Consequently,

they had to devote far more attention to air

quality issues, get a better understanding of the

technical issues and workings of the regulatory

system, and participate actively in policy

debates over how pollution reductions could

be accomplished.

While the states were charged with many

new responsibilities, they were also left with

significant uncertainty about precisely what

complying with the CAAA would entail. As

with most major national legislation, the new

version of the Clean Air Act did not spell out

in detail what all of its provisions required. Instead, it left EPA (in some instances, in consultation with DOT) responsibility for developing detailed federal regulations to implement statutory mandates, including but not

limited to transportation conformity – an effort

that took several years to complete. This

meant that the full scope of new state responsibilities unfolded only gradually, even as statutory deadlines for proposing plans to reduce

mobile-source pollution loomed ahead.

ISTEA. As demanding as the wave of

change that the CAAA set in motion, implementation of ISTEA created a parallel set of

pressures for the state and regional agencies in

the conformity process. Congress enacted

ISTEA in late 1991, and DOT elaborated its

requirements in the metropolitan planning regulations issued in late October 1993, just

before the conformity regulations were issued.
Chapter 4: Institutional Roles in the Transportation Conformity Process 45

Among other effects, ISTEA:

• strengthened MPO authority to conduct the planning process and allocate

federal funds;

• generally permitted greater flexibility

in using federal funds to support the

transportation system, but also created

a new categorical program for projects

with air quality benefits (the congestion mitigation and air quality improvement program or CMAQ); 

• required a more frequent, systematic,

analytic planning process that explicitly

took account of new planning factors,

including (but not limited to) air

quality;

• required the development of a longrange transportation plan to be coordinated with the process for developing transportation control measures

for the SIP;

• encouraged multi-modal planning and

explicit project alternatives analysis;

• required the development of a set of

six “management systems” for intermodal facilities, bridges, pavement,

public transportation, safety, and congestion;1

• reinforced the CAAA’s requirement

that transportation investments be consistent with pollution reduction commitments that a state had made in its

SIPs;

• mandated fiscally constrained transportation plans;

• opened the planning process more

widely to institutions that in many locales had previously been secondary

participants (including local governments, ports and airports, transit operators, and air quality and economic

development agencies); 

• mandated more active efforts to involve the general public and non-governmental stakeholders (such as shippers and freight companies, and environmental advocates) in transportation

planning.

As a result, at the same time that the 1993

conformity regulations were being implemented, ISTEA was reshaping the balance of

power in metropolitan transportation planning

and changing longstanding institutional

practices. MPOs and state DOTs were redefining their own relationships in the transportation planning and programming process,

in some cases tugging and hauling over who

would take the initiative. Both felt pressure to

enhance their technical planning and analytic

capabilities. Simultaneously, because of

efforts to increase participation in planning by

the public, non-governmental stakeholders,

and historically peripheral public agencies,

MPOs and state DOTs were hearing more

voices – some new, many louder – expressing

visions of the purposes regional transportation

networks should serve and how they should

evolve. Throughout, MPOs and state DOTs

were struggling to make politically difficult

choices about regional priorities, as traditional

transportation plans – often featuring so many

projects that, in effect, they constituted “wish

1Congress later made several of these management

systems voluntary rather than mandatory.
Chapter 4: Institutional Roles in the Transportation Conformity Process 46

lists” – were transformed into fiscally

constrained plans. 

State air agencies, for their part, had new

opportunities to participate in and influence

state and regional transportation decision making. To be effective, however, they had to

learn how the planning process worked procedurally, develop expertise in the issues, and

build relationships with other participating

agencies and constituencies.

Against this backdrop of dramatic change

in both air quality regulation and transportation planning, conformity posed significant

challenges for the the key public agencies.

Organizing for Conformity

MPOs. In each of the 15 study areas, an

MPO is the key implementer of conformity.

These MPOs are either single-purpose

agencies established primarily to carry on

regional transportation planning2 or multipurpose regional councils that may also

conduct land use, economic, and environmental planning and regularly bring together

senior officials of the region’s municipal and

county governments.3

 MPO governing boards

are typically composed of local elected

officials or senior transportation agency

officials, sometimes joined by citizen members.

Although MPO governing boards vote the

formal conformity determination, they are

rarely deeply involved in conducting or

evaluating the actual analysis. That is primarily the responsibility of MPO professional

staff.4 A high-level staff member – typically

the agency executive director or deputy

director or the director of transportation planning – closely oversees the process. The

actual transportation and emission modeling is

generally performed or coordinated by a senior

technical staff member, perhaps supported by

another or several other technical professionals

who work full- or part-time on conformity

during the planning cycle. Some MPOs

receive additional support from consultants,

the state DOT, or the state air agency. In addition to conducting the technical analyses for

conformity, the MPO typically organizes and

coordinates interagency and stakeholder

consultations either through specialized “technical” or “policy” committees or by soliciting

agency comments, as will be detailed below.

DOTs. State DOTs in most states are

also significant participants in conformity, even

though the MPO is clearly the lead institution

2These include the Boston MPO/CTPS, NYMTC

in New York City, NJTPA in northern New Jersey,

CATS in Chicago, the Mecklenburg/Union MPO in

Charlotte, and MTC in the San Francisco Bay area

(which also has some transportation operating functions).

3The multi-purpose regional councils are DRCOG

in Denver, the BMC in Baltimore, ARC in Atlanta,

MAG in Phoenix, Metro in Portland, H-GAC in Houston, SEWRPC in Milwaukee, DVRPC in Philadelphia,

and WFRC in Salt Lake City. These organizations

sometimes have a transportation policy committee that

serves as the primary forum for transportation

planning issues, so that the council’s full governing

body deals in detail only with quite prominent transportation issues.

4The MPOs in the study, which are nearly all larger than average and include some of the nation’s largest, have full-time professional staffs ranging in size

from about a dozen to about one hundred personnel.

The Mecklenburg/Union MPO relies on the City of

Charlotte’s Department of Transportation for its staff

capacity.
Chapter 4: Institutional Roles in the Transportation Conformity Process 47

in each study site. At a minimum, one or more

DOT staff, generally reporting to a senior

manager in the planning or environmental division, maintain liaison with MPO technical staff

through regular bilateral meetings and telephone communications – and often by participating in MPO technical committees with

representatives of other agencies. 

Beyond this basic involvement, the role of

state DOTs in conformity varies, depending on

the institutional strength of the MPOs involved, the number of nonattainment areas in

the state, and the degree of difficulty that

MPOs encounter in satisfying the requirements

of the regulations. 

In a few study sites (e.g., Charlotte and

northern New Jersey), the technical role of the

state DOT is greater than in the typical case.

Because the MPOs in these areas have only a

few technical staff members stretched across a

range of transportation planning functions, the

state DOT directly supports the conformity

process by providing data, giving technical

assistance, and sometimes performing elements

of the analysis. In states with multiple nonattainment areas (e.g., California, Utah, Illinois,

Pennsylvania, North Carolina, New York,

Texas), moreover, the DOT needs more inhouse conformity expertise and technical capacity because it is likely to be managing all or a

substantial part of the analytic workload of

conformity for smaller areas. In some states

with several major nonattainment areas (such

as Maryland and Pennsylvania), the state DOT,

often in conjunction with the state air agency,

plays a significant inter-area coordinating role,

helping MPOs in the major nonattainment

areas exchange information and develop

consistent conformity policies and technical

practices.

AIR AGENCIES. In most study sites, state

air agencies perform statewide coordinating

functions, contribute directly to the conformity

technical work of MPO staff, participate in

MPO policy discussions, and review and

critique conformity analyses. In states with

multiple nonattainment areas, air agency staff

help coordinate conformity procedures and

information for the agencies responsible for

conformity in each area. State or regional air

agencies typically maintain the MOBILE or

EMFAC emission models for the nonattainment area,5

 in which cases they supply the

emission factors for the conformity analysis.6

They have also provided technical advice to

MPO staff who work on conformity. In the

course of drafting the conformity SIP, moreover, state air agencies typically have taken the

lead in securing agreement on interagency

consultion procedures, as will be described

below.

OTHER STATE AND LOCAL AGENCIES.

In most of the nonattainment areas in the

study, other state and local agencies have been

marginal participants in conformity. Only in

Denver and the San Francisco Bay area are

there regional air agencies that have been

5Air agencies faced only modest start-up demands

to perform transportation emission analyses. Most already had the modeling capacity in place, so they needed primarily to update as new versions of MOBILE or

EMFAC were released.

6There are exceptions, however. In Arizona, for

example, the MPO is also the lead agency for air planning; so it, rather than the state air agency, performs

the emissions modeling. In Boston, the MPO also does

the emissions modeling in house.
Chapter 4: Institutional Roles in the Transportation Conformity Process 48

closely involved in conformity policy discussions. In some nonattainment areas, other

agencies also provide specific data inputs for

the transportation demand modeling that feeds

into the conformity analysis. For example, the

land use planning agency in Chicago has

worked closely with CATS in developing land

use forecasts; in the Bay area, MTC, the

regional air agency, and the council of

governments, which does land use planning,

have closely collaborated; and transit operators

in several locales (e.g., northern New Jersey

and New York City) provide data and

modeling capacity to MPOs. Most commonly,

however, the perspective of other agencies is

felt in conformity when one or more of their

staff members sit on the consultative

committees organized by the MPO.

FEDERAL AGENCIES. The federal agencies concerned with conformity have had varying degrees of involvement at the state and

regional levels. FHWA is the only federal

agency to have a permanent presence in each

state, as well as regional offices responsible for

groups of states. In states that have significant

air quality problems, FHWA division (i.e.,

state) offices assign a staff member to work

with MPOs and state DOTs on conformity and

other air quality issues. Depending on the size

of the division office and the number of

nonattainment areas in the state, this staff person may work full-time on air quality issues or

combine this task with other planning or

environmental activities. FHWA’s nine regional offices also have air quality specialists,

generally full-time, who, among other duties,

work on conformity issues.7 National-level

FHWA staff in Washington, D.C., coordinate

policy and consult on specialized technical

questions.

EPA has also been closely attuned to the

implementation of conformity. In a number of

the 15 study sites, staff from one of EPA’s ten

regional offices have provided assistance to

MPOs, state DOTs, and air agencies in understanding conformity requirements and carrying

out technical analyses. EPA regional staff

consult regularly with the agency’s national

headquarters staff responsible for conformity

(who are based in Ann Arbor, Michigan) to

exchange information and make sure that

policy positions are coordinated. Unlike

FHWA, however, EPA does not have field

staff stationed in each state. Staff attention to

conformity is therefore more widely spread,

hence less intense in the typical case than

FHWA’s.

The CAAA assigns FHWA and FTA joint

responsibility for the review and approval of

MPO conformity determinations, but FTA has

played a small role in most study sites. Like

EPA, FTA has ten regional offices but lacks a

state-level presence.8 Typically, one of FTA’s

transit planners in each region spends less than

full-time on conformity as a supplementary assignment. It is less likely, therefore, for FTA

7

The Transportation Equity Act for the 21st Century (TEA 21), enacted by Congress in 1998, eliminates funding for these regional offices. Their functions will be partially absorbed by division offices and

by four new technical assistance centers.

8During the latter part of the period that this study

covers, DOT was establishing metropolitan-level offices, including FTA personnel, in some large cities.
Chapter 4: Institutional Roles in the Transportation Conformity Process 49

to be involved in routine conformity consultations. FTA staff members do contribute to

discussion of specific transit-related questions

– especially in areas like Chicago, New York,

or San Francisco, that have major transit

networks and spend substantial proportions of

their federal funds for this purpose.

Developing Technical Capacity

MPOS. Conformity made significant and

stressful start-up demands on MPO technical

capacity and resources, beginning with the interim conformity guidelines in 1991 and intensifying once the 1993 regulations were issued. Most of the MPOs in the study were

subject to the network modeling requirements

of the 1993 conformity regulations,9 and all

needed to upgrade their modeling capabilities

to meet the general requirements of conformity. Typically, MPOs had to hire additional inhouse technical staff and/or consultants for this

purpose. The types of improvements that

study area MPOs instituted in their modeling

and analytic capacity varied, but they included:

• updated input data for population, employment, and land use;

• new travel surveys;

• acquisition of new travel demand software – either through adaptation of

standardized packages or customized

development;

• increased model detail – e.g., to reflect

time-of-day (rather than 24-hour or

peak/off- peak) assignments, arterial

link capacities, signal-cycle variations

at intersections, or volume-capacity

curve variations;

• migration from a mainframe to a workstation or personal computer environment;

• installing or upgrading emissions modeling capabilities, including successive

versions of EPA’s MOBILE model

and, in some cases, development of a

post processor able to perform

emissions analyses for alternative

policy packages without re-running the

full emissions model;10 and

• adding feedback capabilities to reflect

the effect of changes in land use, transportation capacity, and price on travel

behavior – e.g., in terms of number

and length of trips, mode share,

destination choice, and time of day.

While conformity was often the decisive

factor, these upgrades were also motivated by

ISTEA’s planning requirements and the

provision of federal funds to strengthen planning capabilities. A number of MPOs reported

that although they had significantly invested in

developing transportation demand modeling

capacity during the 1970s and early 1980s,

they had made mostly incremental improvements during the remainder of the decade. 

ISTEA required regular updates of regional

plans and explicit analysis of a rich set of plan9

This conformity requirement applied to all ozone

and CO nonattainment areas classified “serious” and

above.

10Only a few of the MPOs in our study did emissions modeling themselves, relying instead on the state

or regional air agency to mount and run the MOBILE

or EMFAC model to provide emissions factors for

MPO conformity analyses.
Chapter 4: Institutional Roles in the Transportation Conformity Process 50

ning factors. This created workload and

technical demands that many MPOs could not

adequately meet. ISTEA, however, also

increased the amount of federal funds available

for planning; and conformity and other

planning needs afforded justification for investing some of these funds in additional

technical staff and modeling capacity. The

pressures of CAAA and ISTEA compliance

thus provided opportunity as well as need for

enhancing technical capacity.

Most of the MPOs in the study now do

transportation demand modeling in-house, although the smaller ones (e.g., Charlotte and

northern New Jersey) sometimes procure assistance from consultants or the state DOT.

Multi-purpose regional councils usually develop demographic, economic, and land use

data and forecasts themselves, while singlepurpose transportation agencies are more likely to rely on other regional or state agencies to

supply this information. Most MPOs depend

on the state air agency to carry the primary

load in emissions modeling, although a few,

including Boston’s, have in-house capacity for

emissions modeling. In Phoenix, unlike any

other study site, MAG has been formally

designated by the governor as the lead air

quality planning agency for the nonattainment

area, so it not only performs conformity

analyses but also develops the area’s SIPs.

During CAAA and ISTEA start-up, even

though many MPOs generally regarded improvements in technical capacity as desirable,

tight regulatory deadlines for new transportation plans, SIP development, and conformity –

as well as active oversight and criticism by

environmental advocates – made managing

these changes quite stressful for many MPOs.

The tight timeframe did not seem adequate for

the magnitude of the task, particularly given a

short supply of skilled transportation modelers.

Competition for their services was intense

given simultaneous recruiting by similarlymotivated transportation (and some air) agencies. Alternatively, building the skills of

current staff or procuring appropriate

consulting services also took considerable

time. The process of making modeling

improvements – typically requiring interagency

consultations, detailed design specifications,

acquisition of software and/or programming,

testing, and implementation – frequently had

to be accomplished in several iterations over a

period of at least two or three years.11

Of the 15 study sites, New York City and

Chicago had the most difficult experiences. In

the early 1990s, alone among the MPOs in the

study areas, NYMTC had no comprehensive

network-based transportation demand model

in place, although New York’s major operating agencies, such as the transit authority,

had specialized modeling capacity for their

own needs. The large task of developing a

network model for the massive and complex

New York region by the January 1995

conformity deadline – difficult enough – was

11This study could not gather systematic comparative information about the monetary costs of upgrading MPO technical capacity to satisfy conformity

requirements. Even if we had had direct access to budget data, our interview subjects had no ready way to

separate conformity-related improvements from upgrades more generally prompted by ISTEA, to identify

or account accurately for in-house costs (especially

where personnel spent some, but not all, of their time

on technical improvement activities), or clearly to

separate capital investments for system development

from operating costs.
Chapter 4: Institutional Roles in the Transportation Conformity Process 51

complicated by a state-mandated hiring freeze

that prevented NYMTC from securing

adequate internal technical staff and by long

delays in letting consulting contracts for model

development. Not until mid-1997 was

NYMTC’s modeling capacity conditionally

certified by FHWA for conformity analysis,

pending further improvements by 1999. In

Chicago, difficulties arose for quite different

reasons. CATS already had an extremely

complex, mainframe-based, network demand

model – but one that could not flexibly accommodate the new kinds of analysis required

by conformity. CATS initiated incremental

improvements, the adequacy of which were

sharply challenged by a coalition of local

environmental advocacy groups, supported by

experts working with the national Environmental Defense Fund. FHWA’s division

office also strongly encouraged further upgrading. As a result, over several years,

CATS made ambitious, expensive enhancements to its models and collected much additional supporting data, including the land-use

forecasts prepared by a sister regional agency.

Litigation threats and the time pressure of

making on-going conformity determinations

during the maiden runs of new model sets

added to the normal difficulty of implementing

major innovations in technical practice.

In northern New Jersey and Baltimore, the

process of technical capacity development coincided with a more general period of rapid

staff growth and development. NJTPA, a new

MPO which had a very small in-house technical staff, inherited some modeling capacity

from NJDOT and NJ Transit, which it

upgraded with consulting support. These

improvements were vetted by an open public

process, with significant participation by environmental advocates led by the Rutgers Environmental Law Center and affiliated with the

Tri-State Transportation Campaign. Baltimore’s newly reorganized MPO took over

the technical resources of its predecessor, but

used consultants to improve its models while

simultaneously significantly increasing the size

of its transportation planning staff. These

efforts were spurred in part by questions raised

about the adequacy of Baltimore’s models by

environmentalists during the interim

conformity period.

MPOs in a number of other areas needed

fewer changes or were able to upgrade their

technical capacity with less difficulty. In the

San Francisco Bay area, MTC had recently

gone through an exhaustive litigation challenge

to its modeling practices brought by the Sierra

Club Legal Defense Fund in 1989.12 The

extensive model upgrades that MTC put in

place as a result of settling the suit influenced

the national policies reflected in the conformity

requirements, and they positioned MTC to

meet those requirements once the 1993

regulations were promulgated. Portland’s

Metro, with very strong in-house capabilities,

refined a set of models that already had been

significantly adapted to deal with air quality

and land use issues. Boston’s CTPS, which

welcomed the overall improvements in

planning capability prompted by CAAA and

ISTEA, upgraded its models for conformity

primarily with in-house staff. In Phoenix,

MAG retained consultants to help it develop

12See Mark Garrett and Martin Wachs, Transportation Planning on Trial: The Clean Air Act and

Travel Forecasting (Thousand Oaks, CA: Sage

Publications, 1996) for a detailed analysis of the Bay

Area situation.
Chapter 4: Institutional Roles in the Transportation Conformity Process 52

modeling improvements over several years –

as did H-GAC in Houston and ARC in Atlanta.

STATE AGENCIES. Compared to MPOs,

state DOTs faced less conformity-related pressure for technical capacity enhancement. Most

had stronger technical capabilities to begin

with, and the areas for which they take primary

analytic responsibility are usually smaller ones

that can utilize less complex methods.

For state air agencies, by contrast, developing necessary technical resources was far

more challenging. As noted above, conformity

was merely one of several types of new transportation tasks that the CAAA set before state

air agencies, each competing for staff attention

and resources. To meet the spate of new responsibilities, most air agencies hired additional staff members who had or could develop

transportation expertise, but this took time;

and new staff had to be assimilated to new institutional practices and cultures. A few state

air agencies (notably in Texas and North Carolina) developed in-house transportation

modeling capabilities, so they would understand better what MPOs and/or the state DOT

were doing and have some independent ability

to assess policy alternatives.

FEDERAL AGENCIES. Both the U.S. Environmental Protection Agency and the U.S.

Department of Transportation contributed to

the development of organizational capacity for

conformity by providing technical assistance.

In a number of areas, MPO and air agency

staff members praised EPA regional office

staff – for example, in Denver and San

Francisco – for assistance in understanding

conformity requirements and carrying out

technical analyses during the early phases of

implementing the 1993 regulations. FHWA

divisional staff also provided a great deal of information to MPOs, state agencies, and other

stakeholders, helping them understand what

conformity required and how it could be done.

National headquarters staff mounted some

more extensive technical assistance efforts –

e.g., to help Denver and Atlanta deal with

conformity difficulties.

Establishing Interagency

Consultation Procedures

Since in all states the planning and operating responsibility for transportation and air

quality policies is dispersed among many individual public agencies – state, regional, and

local – the conformity regulations emphasized

the need for effective interagency consultation

at each stage of the conformity process.

Consultation practices have emerged gradually

as first the interim conformity guidelines and

then the 1993 regulations have been

implemented.

Start-up Issues

As discussed, the early years of CAAA and

ISTEA implementation were fraught with

challenges. As new and sometimes competing

demands were placed on transportation and air

quality agencies, many struggled to understand

and implement their broadened roles and

responsibilities, notably those imposed by

conformity. Given the turmoil of the start-up

phase, it is not surprising that the first round of
Chapter 4: Institutional Roles in the Transportation Conformity Process 53

air quality and transportation planning did not

occur in an idealized manner. As each group

grappled with its own challenges,

transportation and air quality planners did not

always realize the importance of consultation

and place it high on their list of priorities. Also

complicating the start-up of consultation

procedures was a delay in development of the

federal conformity rule, which contains the

most powerful inducements for interagency

cooperation. Initially slated for publication in

1991, EPA instead issued interim guidance

that left many important issues to be resolved

in negotiations with DOT and various

stakeholders. The federal rule was not

completed until November 1993, concurrent

with the deadline for 15% VOC reduction SIP

submittals (in ozone nonattainment areas) and

the first post-ISTEA transportation plan revisions in many areas.

As a result of start-up challenges, many areas missed the window of opportunity for consultation that could have informed the first set

of SIPs in the CAAA/ISTEA era. In a few

areas, such as Boston, Houston and Milwaukee, broad-based SIP planning task forces

were established through which all actors came

to the table (including both public and private

interests from mobile, stationary and area

sources) to evaluate various strategies for

reducing emissions within each source

category; to consider carefully the trade-offs

among mobile, stationary and area source controls; and thus to set budgets with an

understanding of their future implications. In

other areas, air quality agencies dealt with

each emission source category separately. In

these areas, transportation planners were generally a party to TCM decisions and in some

were involved in discussion of other mobile

source measures and emission budgets. As will

be discussed below, however, transportation

planners in several areas were not sufficiently

aware of the importance of their involvement

in SIP planning. Thus, budgets were derived

implicitly from SIP inventories without enough

consideration of their implications for future

conformity determinations. 

Likewise, during the start-up phase, air planners were just beginning to establish their role in

transportation planning. They were jockeying

for a voice in the MPO, learning transportation

issues and planning processes, and had not yet

begun to negotiate the formal consultation

procedures that would be solidified through the

states’ conformity SIPs. Moreover, because

most MPOs and state DOTs had a project

backlog that had already gone through years of

planning and had strong support from local

governments and interest groups, it was quite

difficult politically to influence transportation

priorities in the short run. As a result, air -

planners frequently felt that they had too little

influence on the first post-ISTEA round of transportation plans and TIPs.

Formalizing Consultation Procedures in a Conformity SIP

Part of the conformity SIP that each state

was required to develop by November 1994

involved interagency consultation procedures.

Wide state-to-state variation in institutional

structure, however, made it impossible for the

federal conformity regulations to prescribe

specific arrangements for interagency

consultation, as they did for some other conformity procedures. In drafting its conformity
Chapter 4: Institutional Roles in the Transportation Conformity Process 54

SIP, therefore, each state had to specify a

customized set of policies:

• defining the roles and responsibilities

of each participating agency; 

• establishing general procedures for

meetings, distribution of information,

and opportunities for comments; 

• indicating how certain conformity-specific tasks would be accomplished –

e.g., selecting transportation and emission models, defining “regionally

significant” projects, identifying exempt projects, and determining the

timeliness of TCM implementation;

• specifying how the public would be

involved in reviewing and commenting

on conformity determinations; and

• establishing a mechanism for resolving

interagency conflicts.

Typically led by the air agency, concerned

agencies in most states began working on conformity SIPs in 1994. Although the schedule

for submission of these SIPs did not stay on

track (as will be explained below), many states

finished work essentially within the allotted

year, building on the experience gained in their

initial conformity experiences. Most developed interagency consultation procedures with

little disagreement, and a number regarded the

exercise of specifying responsibilities and

defining processes as quite useful in clarifying

expectations about how conformity would be

carried out.

Although the 1993 conformity regulations

explicitly permitted states to adopt conformity

procedures that were more stringent than the

federal requirements, many states were either

barred by state statute from exceeding federal

environmental requirements or faced an

informal – but powerful – legislative bias

against doing so. Of those that legally could

impose stronger requirements, few chose to do

so. Oregon made its conformity practices

stronger than the requirements in several

respects. Massachusetts also went notably

beyond the federal rule, requiring state air

agency concurrence with the MPO’s

conformity determination.

In a few states, drafting the conformity SIP

became a matter of serious contention between

the MPO and other participants. In Utah, the

state DAQ initially drafted a conformity SIP

based on a model developed by

STAPPA/ALAPCO, a national organization of

state and local air pollution officials, which,

among other provisions, gave the environmental agency a veto over conformity determinations. For its part, the Salt Lake City

MPO insisted on minimal oversight of its

conformity decisions. The two agencies were

therefore unable to reach agreement on conformity procedures.

In Colorado, the state Air Pollution Control Division (APCD) and CDOT jointly led an

intensive interagency discussion about procedures to be incorporated in the Colorado

conformity SIP. This involved participants

statewide, not only those concerned with the

Denver area.13 APCD sought a state

13In addition to APCD and CDOT, other attendees

included representatives from all Colorado MPOs, two

members of the state Air Quality Control Commission

(AQCC), several environmental advocates and

business representatives, and a few unaffiliated citizens.
Chapter 4: Institutional Roles in the Transportation Conformity Process 55

conformity procedure that specified in detail

how the consultation process should work.

Taking an opposite tack, DRCOG advocated

prescribing as little procedural detail as possible to satisfy the conformity mandate. This

would have left more discretion to individual

Colorado MPOs to decide how to comply.

The policy discussions were constrained by a

state law that forbade adopting regulations

that were more stringent than required by federal law. After long, detailed negotiations,

APCD and CDOT eventually reached

consensus, despite the unhappiness of

DRCOG, the Denver MPO. DRCOG was

particularly dissatisfied with a provision that

specified that members of interested advocacy

groups would be permitted to attend all

meetings relating to conformity, along with

agency representatives. The negotiations

about the Colorado conformity SIP coincided

with an intense debate about whether the

Denver PM10 emission budget should be

increased to solve the area’s conformity difficulties, which was ultimately settled by the

state legislature. (These events are described

in more detail in Chapter 3.) Before the conformity SIP was formally adopted, DRCOG

and some business interests indicated that they

would seek changes in the draft conformity

procedures through an appeal to the legislature. APCD then decided to postpone action on the conformity SIP.

Such indeterminate outcomes could remain

unresolved because the original schedule for

finalizing conformity SIPs was placed on hold

nationally. Conformity SIPs were initially

supposed to be submitted for EPA approval by

November 1994, one year after the 1993

conformity rule was issued. By early 1995,

with some state submissions complete and

others still outstanding, the conformity “scene”

was changing at both the national and state

levels. In response to strong concerns raised

by the National Governors’ Association about

the inflexibility and burdens of conformity,

EPA had embarked on national consultations

about how to refine the conformity rule. It

was clear that a set of amendments to the

November 1993 rule would be forthcoming,

which might affect the specific procedures set

forth in the state conformity SIPs. As a result,

EPA relaxed enforcement of the deadline for

submission of conformity SIPs, pending

completion of what were ultimately the August

1997 amendments to the conformity

regulation. These amendments set a new oneyear schedule for submission of conformity

SIPs – by August 1998.

As of the end of 1997, therefore, conformity SIPs for most states in the study were

not yet in final form. Arizona, California,

Georgia, Maryland, Massachusetts, North

Carolina, and Pennsylvania had submitted SIPs

but then accepted EPA’s offer to defer formal

action. This deferral left these states the option

of amending their submissions once the 1997

amendments were promulgated without having

to go through the full state regulatory process

once again. Some other study states –

Colorado, Illinois, New York, New Jersey,

and Utah – suspended SIP development before

their regulations were ready for submission to

EPA. These states therefore had to restart the

process once the 1997 conformity amendments

were issued. By contrast, Oregon, Texas and

Wisconsin submitted conformity SIPs to which

EPA gave formal approval – a fact the last two

states came to regret since it meant that their
Chapter 4: Institutional Roles in the Transportation Conformity Process 56

SIPs would remain in effect until they

developed, submitted, and secured federal

approval for revisions after the 1997

amendments were issued. Oregon, however,

requested EPA approval so that the provisions

that exceeded federal requirements would be

legally binding.

Interagency Consultation in

Practice

Whatever the legal status of their conformity SIPs, the study areas have developed interagency consultation practices that go well

beyond previous levels of interaction. In most,

communication between transportation and air

agencies was minimal before the CAAA of

1990 and ISTEA; in some, virtually non-existent. Consultation began to increase in

response to the initial requirements to develop

SIPs and revise transportation plans.

Conformity was another major spur beginning

with the interim conformity guidelines and

followed by the early stages of implementation

of the 1993 federal conformity rule, when all

involved were struggling to understand the

meaning and nuances of the complicated

regulations.

These emerging relationships have led to

improved relationships in all of the study sites.

But this development has been uneven in its

pace and extent across areas, and important

limitations remain.

REGIONAL AND STATE AGENCIES. As

agencies in each study area have gained more

experience with conformity, consultation processes have evolved and generally deepened.

In virtually all 15 study sites, the MPO is the

organizer and focal point for interagency and

stakeholder consultations on conformity. At a

minimum, MPOs organize meetings of the key

agencies and circulate planning documents for

comment as the transportation planning cycle

proceeds.14 Beyond this, a number of MPOs

(e.g., in New York, Houston, Atlanta, Denver,

and Chicago) host “technical” committees that

meet periodically during the planning cycle and

more frequently when new regulatory issues

are being addressed or problems arise. In

some cases the technical committees existed

before the conformity requirement and have

expanded their membership and functions in

response; in others, they are newly organized.

These groups are typically composed of a

mixture of technical and policy officials from

concerned regional, state, and federal agencies,

including air and transit agencies, FHWA, and

EPA. Sometimes nongovernmental stakeholder groups sit on these committees or attend as observers. Among other activities, the

technical committees may address transportation planning assumptions, modeling upgrades,

specific project implementation issues, and interagency coordination problems – as well as

the ultimate conformity determination.

Consultation goes beyond the mechanics of

conformity in most, but not all, areas. Air

agencies now typically participate in some

fashion on the MPO committees where transportation decisions are made, so they have an

opportunity to make suggestions or raise

issues at a formative stage of policy development. Air quality planners have occasionally

14For Charlotte, the state DOT and MPO both play

key roles.
Chapter 4: Institutional Roles in the Transportation Conformity Process 57

secured formal powers in transportation

decisions. For example, in Boston the

conformity SIP includes provisions for DEP

concurrence on conformity determinations and

DEP’s inclusion in determining the eligibility

of CMAQ projects. On the other side, transportation planners in many areas are brought

into the air quality process through joint committees or task forces that deal with SIP

development and issues such as TCMs and

CMAQ. In most areas, consultation has opened the door for both transportation and air

quality planners to be involved much earlier

and more deeply in cooperative efforts. 

Official interactions, however, tell only

part of the story of interagency consultation.

As interviews conducted for this study amply

revealed, formal consultation procedures have

frequently helped to foster stronger informal

working relationships and deeper understanding of the issues in a number of areas.

Where such relationships have developed, they

are characterized by frequent informal communications across agency lines, not merely

distribution of documents and convening of official meetings.15 Agency personnel discuss

conformity progress and problems, exchange

data and information, provide advice to each

other, and strategize about dealing with stakeholders and other agencies. For example, in

Portland, state air agency and Metro staff have

worked extremely closely on transportation

and air quality issues, along with significant

involvement by the state DOT. Similarly, in

Boston, MPO, air agency, and state DOT staff

have worked quite closely on modeling issues

and development of transportation and air

quality policies. In Denver, despite policy

conflicts, there has been close collaboration

between DRCOG and the regional air agency,

on one hand, and the state air agency and

DOT, on the other; as well as frequent interchanges between regional and state agencies.

In the San Francisco Bay area, there is also

strong collaboration between MTC and the regional air agency and active consultation with

the state agencies. 

As a result of such contacts in these jurisdictions and others, increased professional intimacy and trust developed among the individuals who participate in the conformity

process. Many of the state and regional offi15The formation of both formal and informal consultation patterns seems to be facilitated or impeded by

an important contextual factor – the proximity of

agency offices. Geographic separation of the state

capital (where the state DOT and air agency are

headquartered) and the home of the MPO (usually in

or near the central city of the nonattainment area) can

pose an obstacle – but by no means an absolute barrier

– to strong interagency consultation. When state agency headquarters are at a sufficient distance from the

MPO offices (and those of other involved regional

agencies) to make traveling to meetings time-consuming, inconvenient, and expensive, consultation tends to

be less frequent, more formal, and more likely to occur

with some agencies absent. This is the case, for

example, for New York City/Albany, Charlotte/Raleigh, Philadelphia/Harrisburg, and Chicago/Springfield. By contrast, where the key agencies are located

in the same city – e.g., in Atlanta, Boston, Denver,

Phoenix, Salt Lake City – or where the travel between

the state capital and the central city of the metropolitan

area is relatively convenient – e.g., between Baltimore/Annapolis, Portland/Salem, Milwaukee/Madison

– it is easier for key staff to get together for meetings

and to confer informally. The relatively limited degree

of agency consultation in Salt Lake City and Phoenix,

it should be noted, indicates that geographic proximity

is not a sufficient condition for the formation of strong

relationships. It seems to encourage, but not guarantee, more intensive consultation among state and

regional agencies.
Chapter 4: Institutional Roles in the Transportation Conformity Process 58

cials interviewed for the study stressed that, as

a result of the formal and informal relationships that conformity has spurred, they have

developed a much greater understanding of

their counterparts’ challenges and the constraints that shape their policy approaches,

making it far easier to acknowledge problems

and work together to solve them. Consultative relationships, once initiated, therefore tend

to become reinforcing. Contacts that prove

useful in one instance persist, often deepen,

and become routine. New employees of one

agency meet and get to know their

counterparts at others, if their peers’ relationships have gotten well-established. Because

consultation is a utilitarian activity, however,

the ebb and flow of the work cycle naturally

affects the intensity of these relationships. The

need to produce a “product” such as a SIP or

transportation plan or program, tends to

intensify the relationships; the periods between

such efforts may display less interaction.

These findings about the development of

closer regional and state agency relationships

must be qualified, however, in certain important respects. Even where close interagency

relationships develop, they do not transcend or

submerge distinct institutional interests and

perspectives in conformity. Nor do they fundamentally change disparities of bureaucratic

or political power. Agency personnel continue

to represent their own agencies and may not

always be able to find common ground with

their counterparts on specific matters. Interagency tensions continue to exist, and serious

disagreements can erupt periodically. This

was certainly true in Denver, where disagreements about the PM10 emission budget and the

conformity SIP, among other issues, have divided the concerned agencies.

In some areas, moreover, consultation is

relatively limited and focused to a great degree

on formal interactions such as committee

meetings, review of proposed conformity

determinations by air quality planners, and

comments by transportation planners on

proposed SIP budgets or mobile source control measures. In these areas and some others,

there seems to be far less advance discussion

of issues, less informal give and take, more

turf protection and focus on each agency’s exclusive objectives, and – quite significantly –

less reciprocal trust at the agency and personal

levels.

No single explanation accounts for these

situations, which include Phoenix, Salt Lake

City, and New York. They stem from past institutional and personal relationships, differing

perceptions of individual agency interests, and

conflicting constituency pressures. In Phoenix,

for example, MAG has played an important

part in supporting an extensive regional road

building agenda, which has strong political

support from MAG’s municipal government

members. At the same time, MAG’s role as

both MPO and lead agency for SIP planning -

has given it responsibility for most modeling,

analysis, and policy making. Neither the air

agency nor state DOT matches MAG’s technical expertise in these areas; as a result, MAG

engages in less interagency consultation than

many other MPOs. The state air agency, in

particular, regards MAG as insular and is suspicious of its commitment to air quality goals.

In Salt Lake City, conflict between the MPO

and air agency has arisen over several issues,
Chapter 4: Institutional Roles in the Transportation Conformity Process 59

resulting in poor relationships among some

key staff, mutual suspicions, and limited dialogue. In New York, the air agency and state

DOT have had a wary relationship during most

of the period covered by the study, differing

significantly during national discussions about

the 1993 conformity regulations; both have

also been bureaucratically insular in carrying

out their responsibilities under the CAAA and

ISTEA. Although NYMTC is closely tied to

NYDOT, it has a highly decentralized

structure of regional committees, which creates more participants to consult and more

organizational layers to coordinate; and its difficulties in complying with the network modeling requirements of the 1993 regulations

have focused it more on internal matters than

on interagency collaboration.

Poor interagency communication can make

dealing with conformity problems more difficult than they otherwise would be, as evidenced by Charlotte’s situation in 1997 when

conformity lapsed. As the deadline

approached, there were extensive consultations among planners in the MPO, air agency, and state DOT. Through these discussions, MPO staff believed that the air agency

would revise the emission budget to accommodate higher levels of mobile source

emissions, as the transportation planners had

requested. The air agency decided not to revise the budgets but apparently did not adequately communicate this position to the

MPO, which continued to hope for several

months that this was a viable option. Similar

communication problems between the MPO

and air agency arose in Atlanta as its lapse

loomed in 1997 – in this instance about possible additional emission control measures.

Georgia DOT also controlled much of the

communication between itself and the MPO,

on one side, and FHWA and EPA, on the

other. Whether or not better communication

would have sufficed to “solve” the conformity

problems in Charlotte or Atlanta – and it probably would not have – communication problems wasted time that would have been better

spent in more direct discussions about how to

respond to the conformity lapse.

Even in areas where strong consultative relationships have developed, important limitations remain. While state air agencies provide

important technical inputs to conformity

analysis in a number of study sites, they have

generally been reactive rather than proactive

participants in conformity. Resource limitations and the opportunity costs of using this

scarce capacity for conformity are a major barrier. Compared to the period prior to implementation of CAAA of 1990, air agencies have

built up significantly more staff expertise and

experience in transportation. But the improvement does not fully meet current demands.

Most air agencies still have too few staff members to deal with the wide range of mobile

source issues; given their many tasks, they feel

perpetually short-staffed. So conformity must

compete with other priorities, including some,

unlike conformity, on which the air agencies

must take the lead, particularly SIP

development. Many air agencies in the study

report that staff workload and shortage of

technical expertise prevent them from being as

deeply involved in conformity as they

otherwise might like.

Moreover, because a number of air agencies have little in-house technical expertise on

transportation demand modeling, they are
Chapter 4: Institutional Roles in the Transportation Conformity Process 60

 uncomfortable probing that dimension of conformity even when they have serious reservations about how the MPO is handling it. They

participate in MPO technical committees,

usually speak regularly with MPO staff on a

bilateral basis, and may raise questions in

official comments on conformity analyses.

Rarely, however, do they seriously challenge

MPO technical conclusions.

State bureaucratic politics shapes this result as much as resource scarcity. Many air

agency officials interviewed for this study described their work on conformity in ways that

implied the following perspective: Conformity

focuses on issues at the heart of the policy

domain of powerful political interests.

Transportation projects often have strong constituency backing – e.g., local governments,

business interests, economic development

organizations, construction firms and unions.

The governor, legislators, and local elected

officials pay close attention to these issues and

constituencies. As a result, state DOTs (and

the MPOs with which they are allied) are

among the most politically influential agencies

in state government. By contrast, air agencies

confront a wide range of potentially

controversial matters in addition to

transportation; and they are typically subunits

of state environmental departments, which

have even broader regulatory agendas. Air

agencies consequently must “pick their fights”

carefully. Conformity rarely seems a promising battleground. Disputes have the potential to disrupt the flow of federal funds and

typically relate to the transportation models

about which air agencies have less claim to

expertise than their transportation counterparts. The points of contention, moreover, focus on technical questions that are either difficult to explain to generalist officials (e.g., the

arcana of modeling practice) or seem excessively theoretical (e.g., forecasted emissions

budget exceedances two decades in the

future).

Although such views of political and bureaucratic reality do not preclude challenges to

MPO conformity determinations, they are cautionary. Air agencies therefore seek influence

in conformity mainly through “front-end”

participation on the interagency committees

that discuss planning assumptions and modeling changes, in regular communication and

information exchanges with their counterparts

in the transportation agencies, and, to a lesser

degree, by comments on completed conformity

analyses. When difficulties demonstrating

conformity arise, air agencies usually advise on

ways to reduce or mitigate transportation

emissions, interpret federal regulatory requirements, and serve as intermediaries in

negotiations with EPA regional staff. In only

a few instances identified in the study sites

have air agencies been aligned against

transportation agency positions in major

conformity disputes – most notably, when

DRCOG sought an increase in the PM10

budget for Denver. 

FEDERAL AGENCIES: FHWA. In a number of study sites FHWA personnel are more

tightly integrated into the conformity network

than their counterparts in either EPA or FTA.

In each state in the study, FHWA has division

offices in the same city in which the state DOT

headquarters are located. Therefore, its air

quality staff members have relatively direct

access to their counterparts in state and

regional agencies. In all of the research sites,

FHWA divisional staff participate regularly in
Chapter 4: Institutional Roles in the Transportation Conformity Process 61

MPO technical committees and/or speak

regularly with MPO professional staff, helping

to establish the necessary data inputs and

analytic parameters of the MPO’s transportation demand models and procedures for conformity determinations. This involvement

usually allows them to become aware of difficulties and potentially controversial analytic

choices; to establish working relationships

with key participants from other state, local,

and federal agencies and non-governmental

stakeholder groups; and sometimes to proffer

advice about how troublesome conformity issues might be handled.

In a regulatory role, FHWA staff members

approve MPO conformity determinations. At

an initial stage, they assess whether the formal

conformity determination adopted by the MPO

fulfills basic requirements – e.g., satisfying the

regulations about modeling procedures,

passing the quantitative conformity tests,

showing that TCMs are being implemented,

and demonstrating that transportation plans

are fiscally constrained. While this initial

review typically “checks off” compliance

rather than intensively evaluates the quality of

the MPO’s analysis, it has occasionally

revealed problems that delay approval of the

conformity determination. In Boston, for example, FHWA staff, with the agreement of

FTA, put conformity on hold in 1994 while

dealing with the question of fiscal constraint of

the state TIP. 

FHWA staff members also solicit comments on the conformity determination from

their federal partners, EPA and FTA, and consider comments from interested stakeholders

(most often environmental advocacy groups).

Serious objections typically trigger intensive

review of the MPO’s conformity analysis. In

this process FHWA division staff members

play a facilitative role as well as an evaluative

one. A response to the criticisms is sought

from the MPO. If the disagreement is not

readily settled, FHWA staff members typically

convene meetings at which the interested

parties discuss their positions. In some

instances (e.g., in Chicago during early implementation of the 1993 regulations), repeated

consultations are necessary to work out

differences or determine that an impasse exists.

Within the FHWA hierarchy, the division

offices take the lead in reviewing conformity

determinations. When the issues raised are

primarily local – e.g., questions about how

specific projects should be modeled or whether

certain input data is adequate – the division

office typically has the decisive voice in

approval, with the regional office primarily

providing information and general advice

rather than exercising tight oversight. Some

issues have “policy” implications, however –

for example, if they require an interpretation of

federal regulations that might set a precedent

for other areas or if decisions in other

nonattainment areas are cited as justification

for MPO actions. In these cases, regional staff

typically play a larger role, including coordinating with EPA’s regional offices and

FHWA headquarters.16 FHWA headquarters

staff provide technical backup, interpret

16These relationships are likely to be changed by

the realignment of FHWA field functions that Congress enacted in 1998 in the new Transportation Equity Act for the 21st Century (TEA-21), which succeeded

ISTEA as the nation’s transportation funding

authorization legislation.
Chapter 4: Institutional Roles in the Transportation Conformity Process 62

agency policy, promote inter-area consistency,

and manage liaison with EPA headquarters

staff.17

Although FHWA, acting in conjunction

with FTA as DOT’s representative, has the ultimate authority under the CAAA and the

1993 conformity regulations to decide whether

the conformity determination should be

accepted, it has typically imposed its own

judgments only when conciliation efforts have

not succeeded. In regard to modeling, for

example, FHWA has pressed MPOs for

change but has been willing to accept iterative

improvements over several planning cycles if

the MPOs have been able to institute basic

changes more quickly. In Chicago, for example, FHWA delayed approval of the area’s

conformity determination in 1994, requiring

CATS to conduct extensive further analyses;

but although it pressed CATS to institute

changes in modeling practice as advocated by

a coalition of environmental groups, FHWA

did not ultimately withhold conformity

approval until these changes were fully instituted. In New York, failure to meet conformity’s network modeling requirements is

one reason why the MPO was unable to adopt

a new TIP for several years; but when an initial

operating model was finally ready in 1997,

FHWA accepted the MPO’s commitment to

further upgrading in subsequent planning

cycles. Such decisions have not always

pleased stakeholders, particularly environmental advocacy groups which have sometimes wanted more pressure on MPOs to

upgrade their modeling practices or change

their transportation policies.

The conformity regulations give DOT the

final authority to decide whether an area’s

conformity determination should be certified.

In practice, FHWA has taken the lead; but the

agency has generally worked closely with EPA

and FTA to reach consensus on a federal

position, sometimes managing discussions at

multiple levels of the agencies. In only one

instance in the study sites, however, has there

been severe disagreement between FHWA and

EPA. (The situation in Atlanta was described

in Chapter 3.) 

EPA. Regional office staff members have

played active roles in implementing conformity

– providing technical assistance, troubleshooting on major issues, advising and consulting with national headquarters staff, working with states and MPOs to develop conformity SIPs, and dealing with the conformity

consequences of control strategy SIP revisions

or disapprovals. Nonetheless, EPA’s involvement in conformity at the MPO/nonattainment

area level has been significantly more variable

– and weaker overall – than FHWA’s.

Because EPA lacks a state-level presence

equivalent to FHWA’s divisions, its attention

is more widely spread. The two or three

mobile-source specialists in each EPA regional

office often have many competing demands on

their time, including SIP development and programs such as reformulated or oxygenated fuels, I/M, and, in the early years of CAAA

implementation, the Employee Commute

Option (ECO) program. With a multi-state

purview, moreover, not the single-state focus

of FHWA division personnel, EPA regional

17FHWA headquarters staff, on behalf of U.S.

DOT, also coordinates FHWA, FTA, and the Office of

the Secretary’s ideas and comments on proposed EPA

regulations for which the statute requires concurrence

between EPA and DOT.
Chapter 4: Institutional Roles in the Transportation Conformity Process 63

staff often have responsibility for a half dozen

or more major nonattainment areas, as well as

additional smaller ones. Given the small

number of EPA regional personnel responsible,

managing work flow is problematic.

Transportation planning cycles, roughly synchronized with the federal fiscal year, may

simultaneously hit key periods in several

nonattainment areas; and the demands of

transportation planning may overlap with peak

periods of SIP development.

Achieving equally detailed familiarity and

sustained contact with every nonattainment area is thus quite challenging. Each has different

air quality and transportation problems,

varying institutional structures, and numerous

agency staff and stakeholders with whom to

establish consultative relationships. Geographic distance and travel time from the regional office vary but are frequently substantial. While a number of MPOs have welcomed

EPA participation in area-level planning,

moreover, not all have been equally forthcoming.

All things equal, EPA regional staff are

more likely to be deeply involved in conformity in those cities in which its regional offices are located. Travel is minimized, informal contact is more regular, detailed knowledge is greater. In areas removed from the

regional office site, EPA staff have experienced more difficulty participating as a result

of distance and limited travel budgets (which

was especially problematic during several early

years of conformity implementation). Thus,

EPA staff members based in Region IV in

Atlanta have been closely involved in that area

but have been less active in Charlotte, also part

of Region IV.

Overall, these circumstances seem to have

greatest impact on EPA participation in the

less formal, more routine (but nonetheless

formative) aspects of the conformity process –

e.g., the work of MPO technical committees

discussing modeling improvements or the

parameters of analysis. When EPA staff are

not based in the nonattainment area, their

infrequent personal visits and bilateral

telephone contacts do not fully compensate for

the knowledge and personal relationships that

regular participation in these groups

engenders. It is therefore more common to

hear MPO or state DOT staff involved with

conformity say that they do not know or are

only slightly acquainted with EPA staff than to

hear these people or air agency staff say the

same about FHWA division staff. Some have

come to regard EPA as a “regulator” more

concerned with the formalities of the law than

as a “problem solver.”

EPA regional staff have tended to concentrate their efforts on fulfilling requests for

technical assistance, coordinating with FHWA

staff, and reviewing MPO conformity

determinations. Even the latter work, regarded as highly important, can be squeezed by

time and resource pressures. Final review and

comment on conformity determinations must

be completed on a tight schedule, typically 60

days or less. In a number of EPA regional

offices, moreover, none of the responsible staff

have in-depth experience with transportation

demand modeling, which reduces their ability

to probe MPO work critically. EPA regional

staff have pressed MPOs to improve their

modeling, but they have tended not to raise

formal objections to MPO practices unless

some other agency or stakeholder has done so.
Chapter 4: Institutional Roles in the Transportation Conformity Process 64

Given the volume and diversity of their

workload, EPA regional staff must, of

necessity, pick and choose priorities for

attention. In the typical case, they have

deferred to FHWA judgment on transportation

modeling. The amount of contact between

staff of the two agencies appears to be

substantial, and generally effective “partnerships” have developed at the regional level.

While in some cases EPA staff would have

liked to see FHWA be more aggressive in

challenging MPOs, only in Atlanta has there

been strong disagreement between the agencies.

EPA’s mobile source headquarters staff,

based in Ann Arbor, Michigan, played the lead

role in drafting the transportation conformity

regulations and the subsequent amendments

(in close consultation with DOT, whose

concurrence was required by the statute). It

has also played a continuing role in

interpreting the regulations, coordinating

regional office mobile source specialists to

ensure national consistency, and has communicated regularly with state and regional

transportation and environmental agencies and

other stakeholder groups. The EPA and

FHWA headquarters staffs responsible for

conformity have forged a close working relationship, which has facilitated relationships

between their respective field staffs and with

stakeholders as well as encouraged forthright

discussions of policy differences that have arisen in conformity implementation.

FTA. Like EPA, FTA has ten regional

offices but lacks a state-level presence, which

creates the same difficulties of travel to and

communication with the several nonattainment

areas in each region. FTA’s regional offices

have far fewer staff overall than EPA’s,

moreover, which means FTA faces even more

severe personnel constraints in dealing with

conformity. FTA staff do contribute to

discussion of conformity questions – especially

in areas like Chicago, New York, or San

Francisco, that have major transit networks

and spend substantial proportions of their

federal funds on this purpose. In the typical

case covered by this study, though, FTA

regional offices sign-off on conformity

determinations, usually deferring to FHWA’s

more in-depth review of the issues. The new

metropolitan offices that DOT is currently

opening in some major cities, which will have

both FHWA and FTA staff, may make it

possible in the future for FTA to be more

deeply involved.

Stakeholder Participation in

Conformity

The conformity regulations require both

that the public have opportunity to comment

on conformity analyses before the determination is made and that MPOs fulfill the requirements of the DOT metropolitan planning

regulations, which more generally mandate

public participation in transportation planning.

Using these paths of access, environmental

advocacy groups have been the most active

nongovernmental stakeholders in conformity,

playing key roles in about one third of the 15

study sites and a more limited role in most

others. Business associations are the only

other stakeholder group active in conformity –

and then only in a few nonattainment areas.
Chapter 4: Institutional Roles in the Transportation Conformity Process 65

Environmental Advocates 

Environmental advocacy groups have been

significant conformity participants in a number

of the 15 study sites. In several areas, they

have pressed MPOs hard to upgrade

transportation modeling practices, monitored

(and sometimes challenged) the results of conformity analyses, and used conformity discussions as a forum to advocate alternative

regional transportation and land use policies.

In some areas, they have become well-integrated participants (as official members or regular observers) in the MPO technical committees that structure and review the area’s

conformity practices, sharing in the informal

discussion and information exchange; in

others, they have gained less intimate, more

formal access through public participation

procedures. Wide disparities exist among areas, however, in the resources and expertise

that environmental advocates can mobilize

(and choose to use) to influence the conformity process.

In several study sites, described briefly earlier in this chapter, environmental advocates

have played prominent roles in the

development of conformity practices. In the

San Francisco Bay area, for example, the Sierra Club Legal Defense Fund, in alliance with

other groups, successfully brought suit against

the Metropolitan Transportation Council, the

area’s MPO, challenging the adequacy of its

transportation demand modeling procedures to

forecast the air quality effects of transportation

projects.18 Initiated before the CAAA of 1990

was passed but not fully resolved until several

years after, the debate and resolution of the

MTC suit helped shape Congressional action

and the 1993 federal conformity regulations.

Subsequently, the Sierra Club (not the independent Sierra Club Legal Defense Fund)

has continued to provide support for a loose

coalition of San Francisco area

environmentalists who have pressed the MPO

to accord greater attention to transportation

plans based on tighter land use regulation.

Another example is Denver, where a coalition of local environmental groups – which

also has strong ties to the Environmental

Defense Fund (EDF) and other national

environmental advocacy organizations – has

been extremely active. This coalition has

closely monitored DRCOG’s conformity

practices, lobbied for modeling improvements,

participated energetically in discussions about

transportation priorities (including pressing for

action on transit proposals), helped secure

commitments during the interim conformity

period for environmental mitigation of the E470 toll road project in anticipation of possible

future conformity difficulties, and fought hard

(but ultimately unsuccessfully) to prevent

changes in the area’s PM10 emission budget.

In Chicago, a coalition of local environmental groups, aided by technical experts affiliated with EDF, effectively pressed the Chicago Area Transportation Study (CATS) to

institute major changes in its transportation demand modeling practices. With less success,

these groups have sought changes in the area’s

18See Garrett and Wachs, Transportation Planning

on Trial: The Clean Air Act and Travel Forecasting.
Chapter 4: Institutional Roles in the Transportation Conformity Process 66

transportation policy priorities. In Baltimore,

the Chesapeake Bay Foundation and EDF

raised serious questions during the interim

conformity period about the adequacy of MPO

modeling practices, which helped spur

significant upgrading. Also during the interim

conformity period, several environmental

groups in North Carolina (including the Sierra

Club, the Conservation Council of North

Carolina, and EDF) negotiated with state

agencies to include all transportation projects,

whether or not federally funded, in the

conformity analysis; they also pressed the state

to agree that the state would perform NOx

conformity tests, whether or not the federal

conformity regulations required this. In

northern New Jersey, advocacy groups affiliated with the Tri-State Transportation Campaign, supported by staff from the Rutgers Environmental Law Center, have actively participated in area transportation planning. They

began pushing for technical upgrading of

transportation modeling during the interim

conformity period, and sought public access to

conformity consultations. In Atlanta, the

Georgia Conservancy, Citizens for Transportation Alternatives, and EDF have been active

participants in the conformity-related debate

about transportation priorities, particularly

during controversy about the area’s proposed

interim TIP in late 1997 and early 1998. In

New York, a key national-level Environmental

Defense Fund operative has been an active

technical participant in NYMTC’s efforts to

develop transportation modeling capacity to

comply with the conformity regulations.

These examples indicate that environmental stakeholders have used the conformity

process to influence transportation planning

practices and participate in public debate about

transportation investments and policies. But

not every study site has advocacy groups capable of effective participation. To track conformity well is time-intensive and requires

significant technical skills. In each of the cases

above, advocacy groups have (1) deployed

paid, professional staff to work persistently on

transportation and conformity issues and (2)

have had in-house technical expertise on air

quality and transportation modeling or have

gained access to such expertise through

alliances with national environmental groups

or academic specialists. To participate

effectively, environmental advocates have had

to make efforts that, in many respects, parallel

the involvement of personnel from the core

public agencies. They study federal

regulations and practices; attend numerous

MPO committee meetings typically held during

regular working hours; scrutinize voluminous

planning documents; seek information and

maintain contacts with activists in other

nonattainment areas; discuss the issues informally with local agency staff members, simultaneously building working relationships; and

prepare for and participate in public hearings.

In a major metropolitan area, such activities

may approximate the time demands of a fulltime job. These tasks are also technically

demanding. To review conformity practices

thoughtfully and make credible critiques where

warranted, environmental advocates must have

either a working knowledge of transportation

and emissions modeling or advisers with these

skills. They also need solid working

knowledge of the issues, practices, and

procedures of both transportation planning and

air quality planning and regulation, and must

develop an understanding of how these
Chapter 4: Institutional Roles in the Transportation Conformity Process 67

processes fit together. To the extent that these

groups have credibility as litigators and skill in

attracting press attention, they also enhance

their influence. Environmental advocacy

groups have been forceful players in

conformity when they have people with the

time and technical skills to be productive in

these activities.

While advocates in the San Francisco Bay

area, Denver, Chicago, New Jersey, Atlanta,

and New York have been able to participate

actively in conformity, groups in other areas

frequently lack sufficient personnel and technical expertise to do so. In these situations,

environmental activists typically feel “outgunned” by staff from the public agencies involved in conformity. In Houston, for example, one or two Sierra Club volunteers

joined by a few other activists, each with unrelated full-time jobs and none with professional

training in transportation planning, have

sought to monitor the full-range of transportation policy issues, including (but not limited

to) conformity. Similarly, in Salt Lake City, a

small cadre of part-time Sierra Club volunteers

has monitored transportation issues, including

conformity. In North Carolina, because the

Sierra Club’s volunteer transportation activists

are located in Raleigh, they have not been able

to monitor events in Charlotte closely;

however, they have gotten some part-time

technical advice from a University of North

Carolina graduate student in planning. Lack of

resources puts such groups at a considerable

disadvantage in the conformity process. They

have difficulty staying abreast of planning and

policy development because they cannot

prepare for or attend all relevant meetings, and

they sometimes believe they get insufficient

notice or are excluded. Even when they

actively question analyses and policies, they

often feel uncertain whether they are reaching

the key technical issues of conformity.

Although both adequate staffing and access to technical expertise appear to be necessary conditions for effective participation in

conformity, these are not sufficient conditions.

In several study sites, strong environmental

groups that have focused on transportation

issues more generally have strategically chosen

not to become actively involved in the

conformity process. In Portland, for example,

1000 Friends of Oregon has long had a strong,

influential voice in land use, development, and

transportation policy making. It has been a

major proponent and sponsor of the LUTRAQ

project (land use, transportation, air quality),

which has studied and advocated new strategies to encourage compact urban

development, featuring enhanced transit

service to reduce auto dependence without

compromising mobility. Although deeply enmeshed in the policy arena, 1000 Friends has

chosen not to participate in the conformity

process beyond keeping generally informed.

This has largely been a choice about how best

to use its limited staff resources, made in the

context of generally close working

relationships with both the MPO and the air

agency as well as a belief that the organization

can weigh in if a particular issue warrants

attention.

In Boston and elsewhere in New England,

the Conservation Law Foundation (CLF), a

politically astute policy advocate with strong

litigation capabilities, has been an energetic

force in debates about the environmental

impacts of transportation. In the late 1980s,

it was the key advocate for a multi-billion
Chapter 4: Institutional Roles in the Transportation Conformity Process 68

dollar agenda of air quality mitigation

measures, mainly transit projects, connected to

the huge Central Artery/Tunnel highway

project. It was also an active participant in the

stakeholder task force formed by the

Massachusetts Department of Environmental

Protection to develop policies to meet the

nonattainment area’s CAAA obligations.

Early in the implementation of conformity,

CLF filed unsuccessful lawsuits in Connecticut

and Rhode Island alleging noncompliance with

regulatory mandates. It has not litigated in

Massachusetts, however, nor has it gotten

actively involved in conformity in the Boston

area as a participant in ongoing discussions

through the transportation planning process.

CLF reports that it is devoting less effort in

transportation to such activities and more to

work with grassroots community groups on

specific projects. It has found the air quality

focus of conformity insufficiently broad to accommodate CLF’s larger agenda of concerns

about transportation’s impact on urban life. It

also has come to regard conformity as a difficult tool to use in influencing transportation

choices because conformity analysis occurs at

the conclusion of the planning process, when

fully formed project proposals are ready for

inclusion in plans or TIPs.

In the 1980s, the Tucson-based Arizona

Center for Law in the Public Interest (ACLPI),

won litigation that compelled EPA to bring

transportation policy in Phoenix directly under

federal air quality regulation. While

continuing actively to monitor and litigate air

quality issues in Phoenix, ACLPI has chosen

not to get deeply involved in conformity. It

has been unwilling to commit staff to

participate regularly in planning meetings; feels

that its distinctive competence is in law, not

technical transportation analysis; and sees few

“litigation hooks” in challenging conformity

determinations, given the courts’ inclination to

give broad deference to agency judgments on

technical matters so long as procedural

requirements are upheld.

Business Associations 

Business groups have been active in conformity in only a few of the 15 study sites.

The Greater Atlanta Chamber of Commerce

has followed transportation planning issues

closely and, recognizing the potential importance of the conformity process for regional

development, has argued for policies to restrain growth in automobile use. In other areas, the business community has gotten involved primarily when inability to conform a

transportation plan or program has threatened

the flow of federal funds to the region. In Denver, for example, business representatives sit

on the transportation policy committee of the

MPO and the governing board of the regional

air agency and thus contributed to debate

about Denver’s PM10 conformity problems; but

Denver’s organized business community was

not a key participant. At about the same time,

however, business people were involved in a

task force advising Governor Romer, which

helped push the area forward on transit plans.

In Charlotte, at the end of the study period,

business voices were heard as conformity

stalled the transportation planning process. In

Houston, the business community, closely

engaged by Clean Air Act issues more

generally, has kept abreast of conformity

issues as well, but they have not gotten deeply

involved. Other than these instances, business
Chapter 4: Institutional Roles in the Transportation Conformity Process 69

groups do not appear to track or participate in

conformity to a significant degree, although

they may be actively involved in transportation

policy more generally.

The Broader Visibility of Conformity

The architects of conformity expected that

it would improve the planning process both by

requiring active dialogue among the agencies

and stakeholders and by bringing sharper

analytic tools and better information about

transportation impacts on air quality to bear on

transportation policy making and investment

decisions. Some thought, moreover, that conformity could have wider impact by raising the

public profile of transportation and air quality

issues, educating the public, and increasing the

likelihood that senior policy and elected officials would feel compelled to address these

issues.

Engaging Policy Makers

At least up to the conclusion of the study

period – January 1998 – conformity has not

generally been effective in focusing the attention of high level appointed policy makers

and elected officials on the issues of transportation and air quality. The complex and

highly technical nature of the conformity process has been a barrier to expanding participation in the planning arena beyond the core

group of planning and policy officials who deal

with it on a regular basis, except if major

difficulties arise in fulfilling the conformity

requirements.

REGIONAL POLICY OFFICIALS. At the

regional level, this is particularly the case in

study sites where the MPO is a single-purpose

transportation agency. Because the scope of

responsibility and expertise of these MPOs is

more narrowly based, they are less likely than

the multi-purpose regional councils to attract

active participation from the region’s key

elected officials and general managers

(although a few such officials who are particularly interested in transportation may serve

on the policy boards of these agencies). City

and county managers, mayors of major communities, and other senior elected officials tend

to allocate more time to regional institutions

that have wide-ranging agendas and regularly

deal with politically visible issues.

The active involvement of high-level officials in MPO affairs, whether or not they are

routinely involved in conformity, seems to

make a difference if conformity problems arise.

Although it does not guarantee that the problem can be readily solved, key decision makers

are more likely to focus on the problem when

they are directly connected to the MPO and

have at least rough familiarity with the issues

(e.g., in Denver and Atlanta) than when these

individuals are more distant institutionally and

substantively (as in New York City and

Charlotte). They can become important

participants when solutions must be worked

out with other regional and state agencies, as

well as with FHWA and EPA. Alternatively,

if such officials have not been exposed to

conformity through participation in MPO

affairs, they are likely to learn about conformity difficulties only after area agencies

have gone through lengthy scrutiny of modeling results. The amount of time available
Chapter 4: Institutional Roles in the Transportation Conformity Process 70

before a lapse occurs has then typically shrunk,

and conformity’s technical complexity creates

a steep learning curve that makes it difficult to

appreciate the issues and potential solutions

rapidly.

GOVERNORS. What applies to local public

managers and elected officials is true for statelevel officials as well. Conformity normally

flies below the radar of governors and state

legislatures. The study sites provide few

examples of involvement by these elected

officials in conformity issues. The typical case

is handled routinely, mainly by the MPO,

which is not directly under state government

supervision. 

Even when conformity difficulties arise,

governors’ offices generally remain at a distance. Generalist gubernatorial staffs expect

the agencies concerned to “take care of” such

matters; so long as the agencies are doing so,

they have little inclination to become involved.

If there are conformity disputes between the

state agencies, governors do have authority

under the 1993 conformity regulations to

resolve them. In practice, however, neither

the state DOT nor the air agency has

motivation to let disputes escalate to the

governor’s office (although they may let the

governor or his staff know that difficulties

exist). Senior decision makers on both sides

prefer to work out the issues themselves so

they do not lose control of the outcome.

Moreover, so long as the issues are seen as

primarily “technical” – e.g., concerning

modeling assumptions/practices or out-year

forecasts – governors’ offices are unlikely to

feel well equipped to resolve them.

If it seems necessary to make significant

“policy” changes in order to conform a plan or

TIP – e.g., altering an emissions budget,

changing the control measures in a SIP, or

making significant changes in a transportation

plan – governors’ offices are more likely to

stay informed about the issue but not necessarily to become directly involved. Governors want to choose the situations in which

they either take stands on controversial issues

or bring their administrations into conflict with

federal agencies. 

Even when prolonged conformity difficulties have caused a lapse in federal transportation funding, therefore, governor’s offices

have not necessarily gotten deeply involved in

finding solutions. That was true in Colorado,

where Governor Romer was not directly

involved in Denver’s difficulties in 1994-95,19

and in Georgia, where Governor Miller had

not, as of early 1998, played a major role in

responding to Atlanta’s conformity problems.

When Charlotte’s conformity difficulties finally

threatened a road building project with strong

political backing, however, North Carolina

Governor Hunt visibly intervened, directing his

department heads to become more actively

involved in working out a solution. In

Maryland, moreover, Governor Glendening

vetoed a bill that would have limited I/M and

could have caused conformity problems in

Baltimore, although conformity was not the

sole focus of this decision.

STATE LEGISLATORS. This study has

revealed only one situation in the 15 research

19Although he did not play a major role in

resolving Denver’s conformity problems, Governor

Romer has been actively involved in broader issues of

transportation and air quality policy making in Colorado.
Chapter 4: Institutional Roles in the Transportation Conformity Process 71

sites in which state legislatures or individual

legislators have significantly participated in

conformity matters. Indeed, it appears from

interviews with state and MPO officials and

advocacy group staff members that few legislators have much awareness of conformity

(although legislative action on issues like inspection and maintenance in Maryland sometimes had actual or potential consequences for

conformity deliberations). The exception to

this pattern – controversy in Colorado in

1994-95 over Denver’s PM10 emission budget

– is a significant one, however. Unable to

demonstrate conformity, the Denver MPO

proposed – and the regional air agency supported – raising the emission budget for downtown Denver to a level within federal

standards but higher than had previously been

allowed by the Denver PM10 SIP. This

proposal, bitterly contested by environmental

advocacy groups and the city governments of

Denver and Boulder, was approved by the

state air agency for only a three-year period.

Proponents feared this would lead to conformity difficulties as soon as it expired, even

though it resolved problems in the short run.

Therefore, proponents took their case to the

Colorado legislature (which had previously

created procedures for legislative review of

State Implementation Plans), with the effect

that the increased emission budget was subject

to time limits during the period covered by the

SIP.

Public Visibility

Except in the three areas – Atlanta, Charlotte, and Denver – that have experienced protracted difficulties with conformity or lapses in

federal funding, conformity has had an extremely limited public profile in most of the 15

study sites. This limited visibility is

problematic to the extent that conformity is

intended to serve as a vehicle for educating

citizens about the connections and potential

policy tradeoffs between transportation and air

quality.

PUBLIC PARTICIPATION. The core public

agencies have had limited success in drawing

attention to conformity. To the extent they

have tried to do so, they have relied primarily

on organizing and formally announcing public

meetings, placing notices in their newsletters,

and – increasingly – posting notices and

technical documents on MPO websites.

Consequently, very few unaffiliated citizens

have availed themselves of opportunities for

involvement, even when MPOs and others

have exerted considerable effort to secure

participation. In northern New Jersey, for

example, NJTPA, urged on by environmentalists, made serious efforts in the early

years of conformity to present issues for discussion in public meetings. In the first year,

most of the several dozen participants represented local governments or advocacy groups,

not the general public; and attendance

dwindled in subsequent years. Chicago was

the only study area that reported regular high

attendance at its forums to elicit public

comments on transportation plans and programs. This was accomplished by an intensive

outreach campaign by CATS, independently

reinforced and extended by advocacy groups.

MEDIA COVERAGE. In most of the study

sites, there is scant media coverage of the

transportation planning process in general and

conformity in particular. Unless controversy

arises, conformity is an inherently difficult sub-
Chapter 4: Institutional Roles in the Transportation Conformity Process 72

ject for newspapers, let alone television or

radio, to report. Its highly technical nature,

revolving around complex regulatory

requirements and arcane modeling procedures,

diminishes its accessibility to both generalist

reporters and the public. Because it abstractly

analyzes aggregate regional emissions, conformity usually provides no concrete focus on

either an event or specific projects that might

command the public’s interest and attention.

What is problematic for newspapers is more so

for the electronic media. Conformity is not a

subject that can be conveyed by soundbite

journalism.

Denver, however, is an exception to this

general pattern. The Denver newspapers and

other media have given extensive coverage to

transportation and air quality issues, for example the E-470 project and transit planning.

Conformity has gotten substantial attention

too, primarily but not exclusively during the

1994-95 lapse in federal funding and debate

about the PM10 emissions budget. The newspapers, in particular, not only followed the

day-to-day story line but also periodically published long articles that provided contextual

background. Several factors seem to account

for this comparatively high public profile.

First, the transportation-air quality nexus is not

a new issue for Denver citizens. Prominent

political leaders and organizations have frequently drawn attention to this relationship for

more than a decade. Air quality concerns,

symbolized by Denver’s notorious “brown

cloud,” have been publicly connected to

transportation at least since the Department of

Public Health, CDOT, and business groups

conducted a Better Air Campaign in the

1980s. There has also been widespread debate

about the benefits and threats of the area’s

rapid population growth, burgeoning physical

development, and increasing traffic congestion.

Reporters developed expertise on this set of

issues. More recently, a number of elected

officials in the Denver area, particularly from

Denver and Boulder, have actively sought to

stimulate press and public attention to

transportation and air quality issues. They

spoke out forcefully on the PM10 emission

budget controversy. Similarly, the area’s

media-savvy environmental groups have effectively sought public attention for these issues

through public statements, testimony at public

meetings, and informal contacts with the news

media. These broader concerns about transportation and air quality helped frame public

attention to the area’s conformity problems.

The realistic possibility of an interruption

of federal transportation funding also heightened media attention in other locations. Even

though the newspapers in Atlanta and Charlotte had given less prior media attention to

transportation and air quality issues than in

Denver, coverage notably increased in each

area when the threat of a conformity lapse provided a clearcut news “hook.” As the difficulties in these areas stretched out over many

months, the newspapers not only gave coverage to immediate incidents but also began to

provide more general background on the

issues. Reporters sought out comments from

government and advocacy group spokespersons, increasing their opportunities to

provide facts and interpret the situation. At

the end of the study period in January 1998,

with the Atlanta and Charlotte conformity

lapses in effect, events had not proceeded far

enough to make judgments about how much

attention the general public would give to

conformity – and how this would affect

resolution of the issues.
LINKING TRANSPORTATION AND AIR QUALITY PLANNING:

IMPLEMENTATION OF THE 

TRANSPORTATION CONFORMITY REGULATIONS 

IN 15 NONATTAINMENT AREAS

Arnold M. Howitt and Elizabeth M. Moore

Taubman Center for State and Local Government

John F. Kennedy School of Government

Harvard University

March 1999

A Report to the

U.S. Environmental Protection Agency

and the

Federal Highway Administration,

U.S. Department of Transportation

Publication Number

EPA420-R-99-011

CHAPTER 5: CONFORMITY EFFECTS ON 

TRANSPORTATION AND AIR QUALITY PLANS
Chapter 5

CONFORMITY EFFECTS ON TRANSPORTATION AND

AIR QUALITY PLANS

The conformity regulations anticipated

four strategies by which transportation and air

quality plans can be influenced, either early in

the planning process to ensure that conformity

will be passed or later to correct problems that

have occurred. Areas may:

C craft transportation plans/programs to

take account of air quality impacts in

selecting project locations and alignments and to include projects with air

quality benefits,

C adjust transportation plans/programs

by changing project design or timing

or by removing projects that generate

excess emissions, 

C alter SIP emission budgets by trading

with stationary and/or area sources or

by recalculating mobile source budgets

with updated assumptions,

C add control measures to the SIP (e.g.,

TCMs or mobile source technology

measures like inspection and

maintenance or reformulated gasoline)

to free up room in the budget for VMT

growth. 

This chapter discusses the extent to which

study sites have used these options to deal

with conformity difficulties, analyzes the barriers to their use, and explores the alternate

strategies areas have employed to solve

conformity problems.

Effects of Conformity on Transportation Plans and Programs

Prior to the CAAA of 1990 and ISTEA,

state DOTs and MPOs tended to view transportation primarily through the lens of personal mobility and/or area economic development goals. This often resulted in a transportation system that supported the increasing

movement of people and goods, while minimizing congestion, through provision of new

roads and, to a lesser degree, transit. The

CAAA and ISTEA tried to force a sea change

in this process by making transportation planners also focus on air quality as a goal. To

achieve this goal, while continuing to provide

the mobility necessary to maintain economic

objectives as well, planners would have to

examine alternatives to highway capacity and

the use of single-occupant vehicles. 

Although clearly transportation planners

have become much more aware of and accountable for the impacts of transportation on

air quality, it is too early to draw conclusions

about the full impact of these laws – and particularly the conformity requirement – on

metropolitan transportation systems. As will

be described below, conformity has had significant substantive impacts in a few of the 15

study sites, particularly those that are growing

rapidly in population and aggregate amounts

of personal travel; in others, major changes in

transportation plans/programs in response to

air quality objectives did not materialize during
Chapter 5: Conformity Effects on Transportation and Air Quality Plans 74

the study period.

Firm conclusions about conformity impacts

on transportation plans/programs are premature because of the dynamics of transportation planning and project development.

The conformity regulations presume that air

quality considerations will be taken into account from early project planning through development of an area’s overall transportation

plan/program. At the final adoption stage, if

the conformity tests cannot be passed, the

transportation plan/program can be altered to

solve the problem by dropping, scaling back,

or exploring alternatives to major capacity

expansion projects, or by adding air quality

beneficial projects. 

Because this study covers only the initial

four years of implementing the 1993 conformity rule, however, it could not gauge

conformity’s ultimate impacts. The regulations were not in effect during the formative

years for many of the projects in transportation

plans/programs that were subject to

conformity during the study. This formative

period preceded enactment of the CAAA in

1990 and ISTEA in 1991, as well as the promulgation of the conformity regulations in

1993. Projects thus in the pipeline for years

were not conceived in or evaluated by the

processes established through the CAAA and

ISTEA. Some of these projects were grandfathered before the 1993 regulations took effect, and others were included in transportation plans/programs during early implementation of the 1993 regulations. In effect, the

conformity regulations were applied to the

final stages of planning. It is not surprising,

therefore, that the effects of conformity have

been felt more clearly in the planning process

discussed in Chapter 4 than in the substance of

the plans themselves. Nonetheless, the patterns

that can be discerned from the study are worth

noting.

Effects on Highway Projects

Interim Conformity. During the period

in 1991-1993 that the interim conformity guidance was in effect, although there was considerable initial uncertainty about what this

unfamiliar procedure entailed and how it had

to be documented, most MPOs experienced

relatively little difficulty demonstrating

conformity against this standard. In many regions, plans and TIPs included traffic flow improvements and other system management

measures that promised to reduce congestion,

increase speeds, and thus reduce emissions of

VOCs and CO. 

In some study sites (e.g., New York City,

northern New Jersey, Chicago, and Baltimore), as well as in national forums, environmental advocacy groups disputed the validity of these projections, arguing that because

transportation demand models lacked feedback

loops to show the impacts of highway capacity

enhancements on travel behavior, the true

emission impacts of these infrastructure

investments were not being identified. They

also pointed out other flaws in the analytic

tools used by most MPOs – e.g., that models

lacked sufficient geographic detail to capture

the impact of many relatively small projects on

regional emissions.1 

1See Arnold M. Howitt, Joshua P. Anderson, and

Alan A. Altshuler, “The New Politics of Clean Air and

Transportation” (Cambridge, MA: Kennedy School of

Government, Harvard University, November 1994),
Chapter 5: Conformity Effects on Transportation and Air Quality Plans 75

At the national level, such critiques helped

shape the content of the 1993 conformity

regulations. Other than encouraging some

MPOs to begin adding to their analytic staffs,

however, they had only minor impacts on the

areas under study. In Baltimore, for example,

consideration of the challenge to MPO

modeling practices jointly raised by the

Chesapeake Bay Foundation and the Environmental Defense Fund merely temporarily

delayed the area’s conformity determination.

The only major conformity effect found in

the study sites during this period resulted not

because area transportation agencies had difficulty satisfying the requirements of the interim conformity guidance, but because they

anticipated a more stringent final federal rule.

In Denver, environmental advocacy groups

strongly criticized a non-federal project

proposed by a public toll authority – the E-470

segment of a circumferential roadway. The

advocacy groups contended it would open

new land to development, creating more PM10

emissions than planners were forecasting.

Other transportation agencies sought

assurances that E-470 would not jeopardize

the area’s ability to demonstrate conformity in

the future. Project sponsors eventually agreed

to certain specific mitigation measures and

created an escrow fund to finance additional

mitigation, if that proved necessary.

THE 1993 CONFORMITY REGULATIONS.

Table 5-1 shows recent population and VMT

growth data for the 15 study sites, dividing

them into “high” and “low” growth areas.

Conformity’s impacts on highway projects

have been felt primarily in a number of the

high growth areas – Atlanta, Charlotte, Denver, Houston, Salt Lake City – which found

passing conformity’s emission budget tests

most problematic during the study period. 

Of the other high growth areas, Phoenix

averted conformity difficulties during the study

period by aggressively adopting enhanced

inspection and maintenance and fuel controls

to reduce mobile source pollution but may

encounter conformity problems in the future

given its growth rate and road building plans.

By the end of the study period, Phoenix had

been bumped up to higher classifications for

ozone, CO, and PM10. Portland, which has far

less serious ozone nonattainment problems

than the other high growth areas, has had the

nation’s most stringent growth management

regulations in place since the early 1970s and,

because it has chosen to invest in rail transit,

has comparatively modest highway capacity

expansion plans.

Except for Portland, the high growth areas

in the study tend to have substantial ongoing

land development and significantly rising levels

of VMT (which has often proved higher than

anticipated at the beginning of the study

period). As a consequence, they typically have

major highway capacity expansion plans.

These areas generally have transit systems with

much smaller mode shares than the typical low

growth area in the study – and their population

and economic growth is primarily occurring at

the peripheries of the metropolitan area where

pp. 24-25. Also available under the same title

(Washington, DC: US Department of Transportation,

FHWA-PD-97-010 and DOT-VNTSC-FHWA-97-5,

February 1997), pp. 27-28.
Table 5-1

POPULATION AND VMT GROWTH RATES,

BY HIGHER- AND LOWER-GROWTH STUDY SITES

Percent 

Annual 

Population 

Growth ('90-

'95)

Percent 

Annual 

VMT 

Growth ('90-

'95 or '90-

'96)

Daily 

VMT Per 

Capita 

('95 or 

'96)b

Atlanta 2.7% 4.4% 34.6

Phoenix 2.7% 2.8% 22.2

Denver 2.4% 4.5% 24.4

Salt Lake City 2.3% 4.3% 25.3

Houston 2.2% 3.2% 25.4

Charlotte 2.1% 4.9% 24.2

Portland 2.1% 1.9% 17.2

San Francisco 0.9% 1.8% 19.6

Chicago 0.8% 2.0% 18.4

Baltimore 0.7% 2.3% 23.0

No. New Jersey 0.5% 0.6%a

24.7

Milwaukee 0.5% 1.7% 20.2

Boston 0.3% 1.2% 12.2

New York 0.1% -0.2%c

11.5

Philadelphia 0.0% 1.4% 17.3

a

1990-1999 rate

b

1996 per capita rates calculated using 1995 population data.

c

NYMTC does not regard negative VMT growth in this period 

 as indicative of future trends.

 The sources of data for this table are reported 

 in Appendix IV.

Higher-Growth Areas

Lower-Growth Areas

76
Chapter 5: Conformity Effects on Transportation and Air Quality Plans 77

providing high quality transit service is problematic. On the air quality side, these areas,

with the exception of Houston, have less severe ozone problems than the low growth areas

in the study. Thus, because they have earlier

attainment deadlines, they must show required

reductions, net of VMT growth, more rapidly

than the low growth areas.

Prior to promulgation of the 1993 conformity regulations and in the early phases of

implementation, the looming possibility of

conformity problems encouraged some of

these areas to push as many highway projects

as possible through the NEPA process to

grandfather them. Thus, if and when a lapse

occurred, they would be able to continue to

build for at least two or three years before

feeling the full sting of interrupted highway

funding. Salt Lake City adopted this strategy

in anticipation of a conformity lapse in 1994.

In Charlotte, although no unusual effort was

made to grandfather projects, the area was

able to continue under a conformity lapse during all of 1997 with only three projects

delayed.

When conformity problems did develop,

Denver and Salt Lake City, as will be discussed in the air planning section of this chapter, were able to resolve their conformity problems by altering their air plans or emission

budgets and therefore did not have to make

significant changes in their transportation

plans. In Houston, however, conformity problems in 1994 led to reconfiguration of the

Grand Parkway, a planned third circumferential expressway, which was scaled back in

lanes and capacity.2 In Charlotte, planners and

policy officials, unable to avert a conformity

lapse in early 1997, were struggling to find

ways of solving the problem, with no clear

path to resolution apparent.

Atlanta has most severely felt the impact of

conformity on highway planning. In the early

days of conformity implementation, the northern arc of the Outer Loop was stopped from

moving into the TIP, and many local observers

now doubt it will ever be built. Later,

anticipating a conformity lapse at the end of

1997, Atlanta rushed to complete NEPA

reviews of more than 100 projects (some of

which were major highway expansion projects)

so they could be grandfathered. Because

FHWA had not completed NEPA review or

screened them out as ineligible by the end of

1997, more than 60 projects were not included

in the interim transportation improvement program (ITIP) proposed before the lapse.

Amidst outcries from environmental groups,

EPA raised objections to six of the projects

that did get into the proposed ITIP. It argued

that, although the projects came from a

previously conforming plan, that plan had been

based on outdated assumptions. Because

these projects had the potential to increase

SOV capacity and thus emissions, EPA felt

they should not be allowed during the lapse.

FHWA disagreed with this position, which set

off an interagency dispute that was ultimately

resolved in consultation with the White House

Council on Environmental Quality. An

agreement was brokered among the regional

2At the end of the study period, with its NOx

 waiver expired, Houston was anticipating further conformity problems to develop – with as yet unknown impacts

on its transportation plans.
Chapter 5: Conformity Effects on Transportation and Air Quality Plans 78

administrators of EPA, FTA and FHWA in

which two of the five (including Georgia SR

400) were limited to design and other

preparation work until a conforming plan can

be developed. Another project was removed

from the ITIP by the MPO.

By contrast, implementation of the conformity rule has had far less impact on transportation plans/programs in the older, relatively low growth metropolitan areas in the

study – Chicago, New York, Baltimore, Boston, Philadelphia, Milwaukee, northern New

Jersey, and San Francisco. So far, these areas

have generally not experienced significant

difficulty passing conformity emissions tests

(with the exception, in some cases, of the

build/no build test). Although these areas

typically have more serious pollution problems, they generally have mature highway infrastructure networks, well established transit

systems, and relatively slow VMT growth. As

a result, many projects in their transportation

plans/programs have neutral or positive air

quality benefits. These include reconstruction

and maintenance of the roadway system and

most investments in transit. In these areas,

projects that expand road capacity are often

traffic flow improvements that relieve congestion but do not increase speeds enough to

adversely affect NOx emissions. Due to slow

growth rates, emissions from increased VMT

are more than offset by fleet turnover and the

technology-based mobile source measures

(such as enhanced I/M and RFG) required by

the CAAA in serious and severe ozone areas.

Thus, conformity has not required major

adaptations of transportation plans in these

areas because there are few major capacity

expansions on the table, the mix of projects

already includes many with air quality benefits,

and technology measures are being adopted in

the SIP. In the absence of attainment

demonstrations for these areas, the emissions

budgets that they must meet come from 15%

VOC reduction SIPs and subsequent RFP

SIPs. Moreover, at the end of the study

period, some had not yet determined

conformity against 1999 RFP levels. Because

a number of these areas have relatively severe

pollution problems, some may develop future

conformity difficulties as attainment

demonstrations are developed – and as the

new ozone and particulate standards are

implemented.

INSTITUTIONAL AND POLITICAL FACTORS

IN REVISING TRANSPORTATION PLANS AND

PROGRAMS. How Charlotte and Atlanta will

resolve their lapse problems is not clear at this

writing. While it is possible that major changes will be required in their transportation

plans, that outcome is by no means certain.

What these situations and other less dramatic

cases in the study suggest, however, is how

difficult institutionally and politically it is for

MPOs and state DOTs to make such changes.

As noted above, the conformity regulations

presume that at the final adoption stage, if the

conformity tests cannot be passed, the

transportation plan/program can be altered to

solve the problem by dropping, scaling back,

or exploring alternatives to major capacity expansion projects, or by adding air quality beneficial projects. This view oversimplifies the

transportation planning process, implying a

greater degree of centralized decision making

– both temporal and institutional – than

actually exists. It does not fully take into
Chapter 5: Conformity Effects on Transportation and Air Quality Plans 79

account the way in which policy and political

consensus on the projects that comprise transportation plans is built over a long period of

time, through negotiation and bargaining

among many and diverse interests inside and

outside of government.

MPOs are not autonomous, hierarchical,

executive-driven entities that crisply make and

carry out decisions. They are representative

bodies whose voting members (typically

elected officials or appointed representatives

of local governments) are episodically involved

and have primary interests in and loyalties to

other institutions and/or the communities they

represent. True “regional” interests are few.

Even major projects like turnpikes or

international airports have differential subregional impacts which divide decision makers;

and these projects are always competitive with

– and frequently subordinate to – more

narrowly focused, more geographicallyparochial concerns.

Initial backing to place a project in a regional transportation plan usually comes from

individual localities or major transportation

operating agencies that wish to address a

specific local need or problem, frequently

economic or land development. In larger metropolitan areas, notably New York and

Chicago, there are formal sub-regional processes for developing plans and allocating

funds; in a number of other areas (e.g., San

Francisco and Atlanta) de facto sub-regional

processes exist. Broader support is then built

at the regional and state levels as projects

move through the MPO and DOT selection

processes. Along the way, popular support, as

well as that of developers and myriad other

interests that will benefit from the project

amass behind project plans. The full process

typically takes years, sometimes decades for

major projects. Additionally, there are often

functional or political inter-relationships

among projects that make it difficult to alter or

delete one without affecting others. Thus, because “project selection” is not the result of a

small group of policy makers acting at a single

decision point, it cannot be easily modified or

reversed. Disaggregating the final package of

projects that appear in a regional

transportation plan or program is politically

complicated and time consuming, as recent

experience in Charlotte and Atlanta clearly

illustrates.

A number of forces are thus typically at

play to keep highway projects from being

changed significantly. Political support for

highway capacity expansion tends to be high.

In many of these areas, suburban interests,

which favor projects that expand highway capacity in their areas over transit or other TCMs,

have a majority on MPO boards. Second,

even if MPO boards are willing to curb

highway expansion, they do not have control

over land use decisions that sometimes drive

transportation decisions. For example, in

Atlanta, the MPO could not stop Gwinnett

County’s decision to build the Mall of Georgia

but does have the responsibility to provide

transportation infrastructure to support it.3

Third, some of these areas have developed

modeling results showing that major highway

projects reduce emissions because they relieve

3The MPO board could have voted against the

Mall of Georgia but realized that the project would go

ahead, even without board approval. It therefore decided to support the project on the assumption that the

board would then be in a better position to ask for

some concessions from the developers.
Chapter 5: Conformity Effects on Transportation and Air Quality Plans 80

congestion and offer more direct routes to

motorists’ destinations. Such results were

obtained for the outer loop project in Charlotte

in the period prior to that area’s conformity

lapse. Finally, air agencies, perceiving a significant disparity in political influence with

governors and legislatures compared to state

transportation agencies, are sometimes hesitant

to raise strong objections to specific highway

projects.

 Given the difficulty of extricating projects

from plans, and the length of time that will

elapse before projects in the pre-ISTEA

pipeline are exhausted, it is not surprising that

major changes in the contents of regional

transportation plans have been few. The effects of conformity on the contents of transportation plans/programs will not be fully felt

until/unless air quality goals are systematically

considered early in project planning cycles.

There are some indications that this is

starting to occur. In the study sites, it appears

that, as a result of conformity, proposals for

major highway capacity enhancement, while

not precluded, are less likely to move into

preliminary planning phases than they might

have previously if they seem likely to be

“emission budget busters.” (Some transportation planners report that new project

ideas are subjected to an air quality “laugh

test.”) Those projects that move into the next

stages of transportation planning – e.g.,

generating major investment studies (MIS) –

are likely to get earlier and more intensive

scrutiny for air quality effects than an earlier

generation of projects would have.

Because major highway projects may

threaten financial as well as emissions budgets, moreover, this effect is strongly reinforced by the fiscal constraint requirement of

ISTEA. The research reported here cannot

pinpoint the cumulative effects of these two

provisions of the CAAA/ISTEA planning regime in part because it is difficult to judge

what might have happened but has not. Nor

can it separate their respective causal influences on decisions. But a number of people interviewed in the study believe that together the

emission tests and fiscal constraint requirement

are likely to have a significant long-term

impact on the culture and outcomes of metropolitan transportation planning.

Effects on Transit, Other TCMs,

and Land Use Planning

As Chapter 2 noted, a number of conformity stakeholders, particularly environmental advocacy groups, expected that conformity

would promote specific elements of their

transportation policy agendas. Among the

effects they anticipated were increased transit

investments to make service more widely

available and convenient, more widespread use

of transportation demand management

measures to encourage individuals to reduce

their reliance on single-occupant vehicles, and

tighter coordination of land use and

transportation planning to promote development patterns that require less travel. Although these results were not specifically prescribed goals of the Clean Air Act’s conformity provision, nor of the 1993 regulations,

this study has investigated whether conformity

has had an impact on transit, other TCMs, and

land use planning.
Chapter 5: Conformity Effects on Transportation and Air Quality Plans 81

TRANSIT. Expectations that conformity

would increase investments in transit were primarily rooted in the belief that transit projects

would provide significant benefits in the conformity emission analysis. It was also thought

that the fiscal constraint requirement would

help assure that transit projects that were

included in transportation plans would secure

sufficient funding to go forward. To gauge the

impact of conformity, therefore, the study

team sought to discover whether and to what

degree forecasted emission benefits have

influenced transit planning and decision

making. 

In the 15 study sites, conformity considerations seem to have reinforced – but not determined – transit policies in two areas; but in

others, transit planning has been much less affected by conformity. Contrary to the cited

expectations, most rapidly growing metropolitan areas in the study, including those that

have experienced conformity difficulties, have

not found transit’s emission benefits sufficient

grounds to encourage major investments.

However, although conformity has not

provided incentives for expanded transit in

most study sites, the areas that already have

extensive transit networks have found the

emission benefits of continued investment

helpful in demonstrating conformity.

Denver and Portland are the two study

sites in which conformity has, to some degree,

affected transit policy. In Denver, conformity

has provided additional incentives for

developing light rail transit that was already

well along in the planning stages prior to promulgation of the regulations. Since the area’s

PM10 problems, localized in the downtown

area most efficiently served by transit, could be

partially mitigated by light rail, the area’s conformity difficulties reinforced its intent to go

ahead with this project. The fiscal constraint

requirement, along with prodding by a

coalition of environmental advocates, has also

kept the financial feasibility of proceeding with

transit in the forefront of decision makers’

considerations, although at the conclusion of

the study period the failure of a transit-finance

referendum left doubt about how funds would

be found.

In Portland, conformity has meshed with

and buttressed the area’s pioneering growth

management policies, including the use of light

rail transit to encourage compact urban development. In the late 1980s and early 1990s,

to counter a state DOT proposal for

construction of the Western Bypass, a suburban circumferential freeway, environmental

and transit advocates sought to make an alternative case for extending the area’s nascent

light rail network. Led by 1000 Friends of

Oregon, they initiated the LUTRAQ project, in

close cooperation with key regional, state, and

federal agencies. LUTRAQ consultants used

modeling techniques similar to those

subsequently required by the conformity rule

to analyze alternative land use and transportation policies for the Portland metropolitan area. As a result of the LUTRAQ analysis,

1000 Friends proposed that light rail transit,

rather than the freeway, be built in Washington

County, to anchor moderate-density

neighborhood development along the right-ofway. The analysis showed that this development, when supported by transportation

demand management measures, could accommodate the area growth expected over 20

years. In 1992, Oregon DOT made the

LUTRAQ proposal one of the five alternatives
Chapter 5: Conformity Effects on Transportation and Air Quality Plans 82

it included in the Major Investment Study

(MIS) undertaken on the bypass. Meanwhile,

Metro, the Portland MPO, recommended a

LUTRAQ-like development plan in its Region

2040 Growth Concept, an initial update of its

regional plan. When the MIS, issued in 1995,

showed that the LUTRAQ alternative was

equal or superior to the Bypass plan in most

dimensions, ODOT decided to proceed with

less extensive road improvements rather than

the Bypass. The Portland area is proceeding

with a Westside light rail project and moving

to implement other elements of the LUTRAQ

vision.4 While conformity did not generate the

LUTRAQ analysis and the regional decisions

that have flowed from it, state and regional officials have used the CAAA planning process,

including conformity, to expand and lock in

these policies through the regulatory process.

Some environmental advocates expected

conformity to increase the attractiveness of

transit investments in rapidly growing nonattainment areas with high VMT growth rates,

most of which have relatively limited transit

service. However, in ozone nonattainment areas like Charlotte, Atlanta, Phoenix, and

Houston – which are characterized by quite

decentralized urban development patterns –

even substantial investments in new transit service would produce small changes in transit’s

overall mode share and thus make only small

impacts on the projected net growth of regional emissions. Even the 20-year time horizon of conformity is too brief a period to plan

and institute major investments in transportation facilities and services, let alone to

see changes in travel behavior play out. Consequently, planners and policy makers, even in

the face of the conformity lapses in Charlotte

and Atlanta, have not seen transit investments

as a major way of dealing with conformity

pressures.5 Moreover, our interview subjects

report, when viewed strictly as a way of improving air quality, transit projects often

compare poorly in cost-effectiveness to alternative mobile source control measures – such as

enhanced I/M or reformulated gasoline. Transit may make sense for other reasons, but air

quality alone is not a sufficient motive for large

investments. This effect is intensified by the

preference in many areas for light rail over bus

service, which makes transit even more

expensive relative to the air quality benefits it

can deliver. Except in Denver (where the

geographically concentrated PM10 problem

creates a special case among the study areas),

to the extent that transit is being seriously

considered in high growth areas, it is not

because emission reduction credits weigh

heavily on the decision-making scales. Instead, some in the business community see

transit as an economic development stimulus.

The fiscal constraint requirement cuts two

ways, moreover. Transit financing difficulties

potentially create fiscal constraint obstacles to

including major projects in transportation

4See Keith Bartholomew, “LUTRAQ to Region

2040: From Citizen Alternative to Official Policy,”

Progress (Washington, D.C.: Surface Transportation

Policy Project, March 1997).

5

In November 1998, however, Charlotte voters did

approve a referendum to establish a sales tax

increment for transit. During the same election cycle,

Georgia gubernatorial candidate Roy Barnes made

transit in the Atlanta area a campaign issue.

Subsequently elected, he has proposed expanded

regional transit service.
Chapter 5: Conformity Effects on Transportation and Air Quality Plans 83

plans. Many states have laws that require

them to use gas tax revenues only on roads.

These areas must then raise money for transit

by other means – frequently through sales or

other taxes. Transit funding referenda have

failed in Denver and Phoenix, and Houston has

redirected money from a successful

referendum to other municipal purposes. In

Maryland the legislature passed a 50% farebox

recovery requirement, which has put a damper

on provision of any transit services that cannot

garner half of their operating expenses from

ridership.

While there is scant evidence that conformity has motivated new transit investments, in

study areas that have extensive transit

networks and ridership (e.g., New York,

northern New Jersey, Chicago, Philadelphia,

San Francisco, and Boston), there is no

question that the transit component of the

transportation plan plays a significant role in

each area’s conformity analysis. These study

sites spend substantial portions of their transportation funds on capital maintenance, replacement, and incremental expansion of transit facilities and service. When modeled as

part of the regional analysis, such transit projects generally show air quality benefits that

partially offset emissions from VMT growth or

additional road capacity (or are neutral in air

quality effects). In a few cases, moreover, offmodel analysis of transit projects (e.g., the

purchase of alternative fuel buses in Chicago

and replacement buses in Boston) has helped

areas pass build/no build tests that might

otherwise have proved problematic. 

Nonetheless, the individuals interviewed in

these study sites did not regard potential emission impacts on the conformity analysis as a

significant influence on decision making either

in terms of the transit budget share or the

types of projects supported. The direction of

influence in such cases is from transit to

conformity, not the reverse. Because of strong

local political demand for transit, it appears

that these areas would have spent their money

on transit projects anyway. In some cases,

interview subjects did note, transit investments

became attractive or jumped higher on area

priority lists because they qualified for funding

under the Congestion Mitigation and Air Quality (CMAQ) program created by ISTEA to

promote compliance with CAAA

requirements. But this incentive effect was

independent of the conformity requirement and

would have operated were the latter not in

place. In the Chicago and Boston cases

referred to above, for example, area planners

performing the conformity analysis simply

took advantage of bus purchases that had already been decided. 

TCMs. While the conformity regulations

do not compel areas to include TCMs in their

SIPs, conformity does require that TCMs that

have been written into SIPs be implemented in

a timely fashion; and the regulations protect

certain types of TCMs as exempt projects.

These provisions, coupled with the expectation

that TCMs would show emission benefits, led

some to believe that conformity would

increase the adoption of TCMs in

transportation plans/programs.6 Conformity,

however, does not appear to be having this

effect in the study sites. Although many

6The section on “Conformity and Air Quality

Planning” later in this chapter includes a discussion of

the degree to which TCMs have been included in SIPs.
Chapter 5: Conformity Effects on Transportation and Air Quality Plans 84

MPOs in the study have adopted TCMs –

including traffic flow improvements, park-andride lots, and HOV facilities – in transportation

plans/programs, interview subjects do not regard conformity as the main impetus for doing

so. 

Only two areas reported adopting a TCM

specifically for conformity purposes. Boston

added a noncontroversial CMAQ project to

the TIP to pass the build/no-build tests in

1995. In Baltimore, where a new TCM resolved TIP conformity difficulties triggered in

1995 by the status of the ECO program, the

situation was far more complex politically.

The 1994 Baltimore transportation plan had

assumed implementation of the then mandatory federal ECO program. But Baltimore

business interests strongly opposed the ECO

mandate out of concern that the program

would put their region at a competitive

disadvantage with the Washington metropolitan area, which was not subject to ECO. Governor Glendening responded to the political

pressure in May 1995 by declaring ECO a

voluntary program, notwithstanding the

federal mandate; and the legislature cut all

Maryland Department of Environment (MDE)

funding for the program.7 When the MPO

staff nonetheless plugged ECO into the conformity analysis to offset NOx

 emissions in

future horizon years, MDE expressed discomfort that a program for which it had no

funding and no implementation plans was used

in the analysis; and the Sierra Club Legal Defense Fund (SCLDF) questioned the claim of

full emission credit for a voluntary program.

The MPO therefore proposed a regional

commuter assistance program (RCAP), to be

financed with transportation funds and implemented by the MPO staff in 2005. Because

RCAP claimed minimal emission reduction

credits and did not rely on MDE for staff or

funding, SCLDF and MDE no longer objected

to its use in the conformity analysis. The

RCAP program, not scheduled for

implementation until 2005, has been refined

and supplemented in subsequent conformity

analyses.

In other areas, the availability of CMAQ

funding has probably increased the attractiveness of some TCMs relative to other possible

expenditures; and many areas routinely use an

off-model analysis of TCMs to pass the

build/no-build test. Because most show only

modest air quality benefits, however, other

factors have driven their inclusion in area

plans; they have not been programmed specifically to capture air quality benefits. Indeed,

environmental advocacy groups have argued

against some of these projects (particularly

transportation system management – TSM –

projects intended to use existing infrastructure

more efficiently), even when MPO modeling

shows conformity benefits, on the grounds that

by reducing congestion they will ultimately encourage more drivers to use the road. In each

of the study sites, restrictive transportation

demand management measures that might have

large air quality benefits – e.g., various forms

of pricing incentives – are regarded as too

politically volatile to adopt. Only San

Francisco seriously considered – but did not

adopt – such policies during the study period.

The adoption of the RCAP program in

Baltimore shows that under some circum7

It was not until later in 1995 that Congress passed

legislation making ECO voluntary.
Chapter 5: Conformity Effects on Transportation and Air Quality Plans 85

stances the conformity regulations can give

both external stakeholders and public agencies

policy leverage that they might otherwise lack,

but a commitment to initiate a voluntary

regional program ten years hence is a quite

limited outcome. Conformity incentives,

moreover, did not prove strong enough to

prevent Maryland’s elected officials from

defying the federal ECO mandate, even though

it was a TCM written into a SIP, which therefore required timely implementation under the

conformity regulations.

LAND USE PLANNING AND REGULATION.

Neither the CAAA nor the conformity rule require that areas consider or adopt land use

controls to constrain transportation and thus

mobile source emissions. The conformity rule,

however, does require the use of a networkbased transportation demand model that

relates travel demand to land use patterns, as

well as demographic and employment trends,

transportation infrastructure, system performance, and policies. Some proponents of conformity hoped that modeling the transportation/land use links would also lead to consideration of alternative land use scenarios in the

planning process and wider acceptance of land

use regulation as a viable policy option for reducing mobile source emissions.

As described in Chapter 4, this requirement

spurred transportation modeling enhancements, some of which were targeted specifically at improving MPOs’ capacity to

forecast the reciprocal impacts of transportation and land use and relate these to air quality. In turn, better information about how land

use patterns, transportation facilities and services, and air quality interact over time, has

contributed to regional discussion of alternative land use scenarios. In Denver, these issues have gotten substantial public attention.

Existing public concern about the consequences of growth increased in response to

the area’s conformity difficulties and the controversy over the PM10 budget. In 1995, newly re-elected Governor Romer kicked-off a

year-long “smart growth” campaign that

brought together a large group of business and

environmental leaders from around the state.

Spurred by this initiative and expanding public

interest in regional growth issues, DRCOG unveiled its Metro Vision 2020 plan, which

recommended constraining metropolitan

growth within a 700 square mile area,

protecting open space, and committing to

transportation alternatives that would support

these land use policies. Although DRCOG

lacks policy tools to enforce the plan on local

government land use decision makers, its

transportation policies have sought to promote

growth along the lines proposed in Metro

Vision 2020. In some other areas – e.g.,

Milwaukee and Philadelphia – transportation

infrastructure plans are intended to support

specific land use and development scenarios.

As the Denver example indicates, however,

the impact of conformity on actual land use

decision making is limited by the distribution

of institutional responsibilities and the politics

of land use regulation in the 15 study sites.

Except in Portland, authority for land use regulation is a prerogative of individual municipal

or county governments, not the state and

regional institutions that largely control

transportation and air quality deci-
Chapter 5: Conformity Effects on Transportation and Air Quality Plans 86

sions.8 In other states, municipal and county govern

ments tend to resist efforts by higher level

governments to regulate their land use authority. Although federal transportation planning regulations require local governments to

be represented on MPO boards, not all municipalities in an area serve; and in no situation is

the full set of municipal land use decision

makers for a given locality involved. Consequently, the public entities with land use decision making authority are not systematically

involved in conformity. In San Francisco, for

example, at the urging of a coalition of

environmental advocates, MTC modeled a

transit-oriented land use scenario. Although

this scenario showed significant air quality

benefits, MTC rejected it as a plausible basis

for transportation decisions, arguing that

neither the probable actions of land use

regulators nor market trends for the location

of residences and economic activity were

actually likely to produce the patterns of land

use that the scenario presumed. Even in the

sphere of land use planning, only some of the

MPOs in the study sites – e.g., in Atlanta,

Denver, Philadelphia, Salt Lake City, Houston,

and Milwaukee – are comprehensive planning

agencies whose scope of responsibility

includes regional land use planning. In a

number of areas, land use planning is the

province of other entities that are less centrally

involved in conformity than the MPO.

Portland is the single major exception. As

related above in discussing the LUTRAQ policies, Metro, which is both the regional land

use agency and the MPO, has legally buttressed its growth management policies by getting the state air agency to incorporate them

into the SIP, which makes them federally enforceable through conformity. By contrast, in

most other study sites, land use decisions are

only weakly coordinated with transportation

planning and air quality regulation; and the

government bodies that hold and implement

the actual regulatory authority over land use

operate quite independently. 

Conformity and Air Quality

Planning

In examining the impacts of conformity on

transportation plans and policy, this chapter

has been focusing primarily on the effects of

air quality regulation on transportation. But

through conformity, transportation has also

had significant effects on air quality planning,

an outcome that deserves close attention. As

intended, conformity links the sequential

development of transportation plans and

programs through the years, on the one hand,

and the similarly sequential preparation of state

implementation plans to fulfill CAAA

requirements, on the other. In what ways and

how well has it done so? This section

examines the degree to which conformity has

influenced the first post-1990 air quality plans

and subsequent SIP planning efforts.

1992 CO and PM10 SIPs

Several factors were at play during the startup phase of CAAA/ISTEA implementation that

prevented conformity from having a larger

influence on the first round of SIP planning. As

8Maryland also has a growth management regulatory system; however, it is much weaker than Oregon’s.
Chapter 5: Conformity Effects on Transportation and Air Quality Plans 87

discussed in Chapter 4, the timing of the federal

conformity regulation’s promulgation limited

conformity’s impact on the initial phase of air

quality planning. Transportation and air quality

planners were under tremendous pressure

juggling the myriad new demands placed on

them by the CAAA and ISTEA. Because the

conformity regulation was not written until after

the submission date for CO and PM10 SIPs in

late 1992, these plans were developed without

knowledge of the regulation’s final form or clarity about its implications for SIP planning.

1993 VOC Reduction SIPs

Although the subsequent notice of proposed rulemaking for conformity, issued in

January 1993 as the Bush administration was

leaving office, alerted some ozone nonattainment areas to the importance of conformity at

a relatively early stage of developing their 15%

VOC reduction SIPs, the final conformity

regulation, developed under the new Clinton

administration, was not published until November 1993, a few days after the 15% SIPs

were due. Some states were closely attuned to

the national discussions about how the conformity regulations should be written9

, while

others more passively awaited the final regulations before turning attention to the implications of this new procedure. As a result,

the degree to which conformity considerations

did influence planning for the 15% SIPs varied

widely.

Even in areas where the importance of the

issues was clearly appreciated, the delayed release of the final version of 1993 regulations

left working-level transportation and air

quality planners with an incomplete picture of

the requirements that would be placed on

them. In a few areas – including Boston,

Houston, and Milwaukee – broad-based stakeholder task forces participated actively in SIP

planning. In these areas, because an overall

SIP strategy was debated, stakeholders,

including transportation agencies and interests,

came to understand the tradeoffs inherent in

selecting specific control measures. They also

began to address what would be necessary to

bring the area into attainment. Through this

process, the forthcoming regulations were

conceptually addressed, even though the final

conformity requirements were still uncertain.

In some other areas, even though a comprehensive stakeholders process was not convened, the future implications of air quality

regulation for transportation were also clearly

addressed. In the San Francisco Bay area, the

MPO was responsible for drafting the mobilesource elements of the SIP and was broadly

experienced with emissions forecasting issues

as a result of the litigation of the late 1980s

and early 1990s. In Phoenix, where the MPO

was also the lead agency for air planning and

the state legislature was proactively involved,

mobile source issues figured prominently in

policy making. In Oregon, a state-level

Governor’s Task Force on Motor Vehicle

Emissions developed strategies that influenced

the Portland SIP.

9The San Francisco and Denver MPOs, for example, followed these discussions closely. In some

states in the study – notably Pennsylvania and New

York – state air agencies and DOTs were actively involved but took quite different positions in lobbying

nationally on how the conformity provision of the

CAAA should be operationalized.
Chapter 5: Conformity Effects on Transportation and Air Quality Plans 88

In other areas, however, the air agency

dealt separately with the stakeholders in each

source category and focused primarily on

short-term regulatory requirements. In some

of these areas – e.g., Atlanta, Baltimore, Chicago, Milwaukee, New York, and Philadelphia

– transportation agencies, concerned about

future conformity requirements, made efforts

to influence mobile source emission budgets.

However, lacking both the need to implement

measures beyond those federally mandated and

a broad stakeholder forum in which difficult

decisions could be discussed, the air agencies

chose not to broach directly the politically difficult question of how emission budgets would

be allocated over time. In several areas

(including Baltimore, Chicago and Milwaukee), air planners nonetheless responded to the

transportation agencies’ concerns. They explicitly chose to accommodate mobile source

growth in their 15% SIP budgets by using

liberal VMT growth estimates. These created

a future mobile source cushion for SIP purposes as well as for conformity.

Of the 15 study areas, decisions made

during this period subsequently created conformity problems for both Charlotte and Salt

Lake City, moderate ozone nonattainment

areas that decided to seek redesignation to

attainment rather than write a 15% VOC

reduction SIP. Redesignation was attractive

because, as attainment areas, they could avoid

implementing some SIP measures that were

required in moderate nonattainment areas and

could escape the disadvantages faced by

nonattainment areas when trying to attract new

business locations or expansions. To avoid the

penalties associated with a finding of failure to

submit the 15% SIP, these areas were under

tight time constraints to develop attainment

demonstrations and write ten-year maintenance plans. In neither case, however, did

transportation and air planners fully probe the

inter-relationship of this choice with the

emergent conformity regulations. 

In Charlotte, transportation planners did

too little to explore and call to the attention of

air planners the implications of conformity for

future transportation policies; and air planners

were focused on fulfilling the immediate

regulatory requirements for redesignation. As

refined transportation demand modeling

subsequently showed that VMT growth rates

would be significantly higher than anticipated

in the maintenance plan, the emission budgets

caused the severe conformity difficulties

described in Chapter 3.

In Salt Lake City, the MPO realized late in

the redesignation process that the maintenance

plan mobile source budgets would cause future

conformity problems. However, because a

CAAA sanctions clock for failure to submit

the 15% SIP was about to expire, the MPO

supported the maintenance plan and later

sought to address the budget problems

through a SIP amendment. In both areas,

transportation planners eventually came to

believe that stationary sources had actively

sought a growth cushion in their budgets

during bilateral negotiations with the air

quality agency. Whether or not the perceptions expressed above are correct, it is clear

that transportation planners in these areas were

not aware of or engaged enough during the

redesignation process to fully understand the

future impacts on mobile sources and thus to
Chapter 5: Conformity Effects on Transportation and Air Quality Plans 89

make sure that intersectoral tradeoffs were

clearly addressed in setting emission budgets.

Effects on Subsequent SIP

Planning

As areas have moved through subsequent

rounds of air quality and transportation planning, conformity has had more impact on the

setting of mobile source budgets. In most areas, transportation planners have been much

more involved with the 9% and attainment

year budgets, although in several (e.g., Atlanta, Philadelphia and New York City)

transportation planners have not been deeply

involved in negotiations until after preliminary

budgets have been set and transportation

agencies must react through comments. In the

face of conformity problems some areas have

adjusted or amended mobile source budgets.

Other areas have proactively reassessed

emission budgets to anticipate and deal with

looming conformity problems. 

Overall, this activity represents a major

change in the practice of transportation and air

quality planning. Even where bureaucratic

relations have been far from smooth, the

previously separate planning and regulatory

processes have become far more tightly linked

than ever before. Just as air planners have become more significant and involved stakeholders in transportation planning – as described in Chapter 4 – transportation planners have

become more active stakeholders in air

planning.

Conformity has spurred this process in two

main ways: (1) by stimulating greater scrutiny

of and refinements in the current data and

forecasting techniques for transportation

demand, and (2) by forcing planners and policy

makers to identify, confront, and more directly

assess the options they have for reducing mobile source and other emissions. In some

areas, this has resulted in refinements of

mobile source emission budgets to accommodate transportation needs or, less frequently, adoption of additional control measures to mitigate transportation emissions. In

other areas, however, transportation interests

have not secured the SIP changes they have

sought to alleviate conformity problems

resulting primarily from higher rates of VMT

growth than anticipated. Unresolved differences about how to deal with these problems

account for the conformity lapses that existed

in Charlotte and Atlanta at the conclusion of

the study period. Nonetheless, to a far greater

degree than in the past, the implications of

transportation growth are being carefully

considered in air pollution regulation.

MODELING COMPLICATIONS. The complexity of the modeling process and the interrelationships between conformity and SIP

modeling, however, have frequently made it

difficult to get to the heart of these issues

about transportation growth. As discussed in

Chapter 3, passing the emissions budget tests

has been the most difficult conformity hurdle.

Although VMT growth rates are fundamental

to most budget test problems, some difficulties

have been caused or exacerbated by modeling

issues. These include the reliance on HPMS

data for VMT estimates in SIP budgets and

the requirements that areas use the latest

planning assumptions and the most recent

emissions model for the conformity analysis.
Chapter 5: Conformity Effects on Transportation and Air Quality Plans 90

When conformity problems are primarily

caused by the disparity in modeling techniques,

resolving the problems has frequently proved

time-consuming but possible for the agencies

concerned. However, when the conformity

difficulties reflect underlying problems of substantively meeting Clean Air Act mandates

rather than modeling artifacts, the process of

clearing away the modeling confusion has tended to delay dealing with the basic issues of air

pollution reduction.

In the 1993 conformity rule and guidance

on VMT forecasting and tracking, EPA, with

FHWA concurrence, specified the use of

HPMS data as the preferred method for calculating VMT to establish the emissions levels

on which SIP budgets are set. However, the

conformity rule also required that areas use

network-based transportation demand models

to generate the VMT forecasts on which

emissions estimates are calculated for the

conformity analysis. Thus, in some cases,

because different methods may have been used

to calculate emissions in the budget and

analysis years, conformity problems may not

be due to actual changes in emissions. Some

areas, including Charlotte in 1994, have dealt

with this problem by making adjustments in the

conformity analysis. Others (e.g., Boston and

New Jersey) have chosen to amend their SIP

budgets using VMT forecasts from the travel

demand models to avert future conformity

problems. Three areas (Baltimore, Phoenix

and San Francisco) avoided this problem altogether by using VMT estimates from the

travel demand models to set the SIP budgets

initially.

In addition, the conformity rule requires

that areas use the most recent planning assumptions in their conformity analyses. To

comply with this requirement, areas have updated their estimates of population, employment and travel for use in the transportation

models, significantly refining the parameters

that had been used to develop the budgets and

thus sometimes “finding” more emissions than

were reflected in the budgets. Likewise, the

use of updated versions of the MOBILE model

increased the estimates of certain emissions,

under the same conditions. Thus, if an area

used MOBILE 4 to set its budgets and

MOBILE 5 in the conformity analysis, an

increase in emissions might be due to the

difference in the models.

An example of this occurred in Salt Lake

City in 1994 when the area’s first budget test

problems occurred, and the area lapsed after

failing to pass the NOx budget test for PM10.

Transportation planners eventually convinced

EPA that this failure was not due to real

emission increases, but was due to changes in

the MOBILE model. The PM10 budgets were

established using MOBILE 4, prior to the

promulgation of the 1993 conformity regulations, while the conformity analysis later

used MOBILE 5, which calculated much

higher levels of NOx from mobile sources.

With permission from EPA, also granted to a

few other areas, Salt Lake City has since

continued to use MOBILE 4 for NOx conformity for PM10. 

CHANGINGSIPS TO SOLVECONFORMITY

PROBLEMS. All of the areas that have had

serious problems passing the budget tests

(Atlanta, Charlotte, Denver, Houston, and Salt

Lake City) have responded by attempting to

alter the modeling underlying mobile source

emission budgets or to enlarge the mobile
Chapter 5: Conformity Effects on Transportation and Air Quality Plans 91

source share of the aggregate budget to

accommodate high VMT growth rates. At the

urging of transportation planners, air planners

for Atlanta and Charlotte discussed budget

amendments, but chose not to alter them. Air

agencies did amend the Denver and Salt Lake

City budgets and in Houston made technical

corrections to a submitted, but not yet

approved, budget to solve conformity problems. (For further discussion of these areas’

conformity problems, see Chapter 3.) Proactively, Portland established out-year emission budgets in its 1996 ozone maintenance

plan to make future conformity determinations

less difficult.

Atlanta’s budget problems began to

emerge as the area updated its modeling assumptions in 1995. When the area could not

pass conformity in 1996, planners considered

amending the mobile source budgets using

modeled VMT estimates rather than HPMS

projections. However, they quickly realized

that, due to much higher than anticipated

VMT growth, if the budgets were revised, the

SIP would no longer demonstrate attainment,

as the planned measures could not offset the

higher emissions levels. Under these circumstances, the area lapsed and is in the process of re-examining SIP budgets and control

measures in the attainment demonstration and

developing a long-range transportation plan

that can conform.

When Charlotte encountered its first conformity problems in 1994, the area attributed

the budget test failure to the differences in the

methodologies used in the budgets, based on

HPMS VMT projections, and the conformity

analysis, based on modeled VMT levels. The

air agency used a reconciliation technique to

make the two methodologies more comparable

and thus demonstrated conformity. In

subsequent years, new modeling revealed

higher than predicted VMT growth rates,

making it impossible to demonstrate conformity and leading to a conformity lapse.

Efforts to resolve the problem have been

complicated by differences over modeling.

Transportation planners continued to consider

changes to the assumptions on which the

budget was based as part of an overall strategy

to pass conformity. For example, they

weighed the possibility of re-examining some

of the default inputs in the MOBILE model,

believing that the functional class percentages

did not accurately represent the area’s vehicle

fleet. By the end of the study period, it was

clear that modeling changes alone would not

resolve the conformity problem. It was not

clear, however, how the area could or would

address the underlying problem.

As described in Chapter 4, Colorado

amended Denver’s mobile source PM10 budgets to resolve its 1994 conformity lapse. The

result was establishment of out-year budgets

that increased regionally over time, while emissions in the core area were mitigated to keep

them within allowable limits. In addition, the

area is required to use dispersion modeling to

ensure that the spatial distribution of the emissions does not cause violations of the standard.

In 1995, Utah amended the Salt Lake City

budget in its ozone maintenance plan to ease

problems passing the NOx budget test for

ozone. By adding ten years to the budget, the

area was able to demonstrate that, without

adding any additional control measures to the
Chapter 5: Conformity Effects on Transportation and Air Quality Plans 92

SIP, NOx emissions could rise after the first

ten years of the maintenance plan without

causing a violation of the NAAQS. With the

extended, higher budgets, the area could show

conformity to the end of the 20-year

transportation planning horizon.

In Houston, planners made technical corrections to a submitted (but not yet EPA-approved) budget in 1997 to pass the VOC budget test for ozone. By switching to modeled

VMT estimates rather than HPMS VMT and

by correcting for an over estimation of VMT

on local streets, the area revised the budgets

and demonstrated conformity.

In developing its 1996 ozone attainment

demonstration/maintenance plan, Oregon took

a proactive approach to future Portland conformity determinations by setting emission

budgets for ozone precursors for the years beyond the milestone year of the maintenance

plan. Quantifying its safety margin between

total emissions in the attainment year (1992)

and 2006, it gradually allocated part of this

safety margin to create somewhat larger mobile source emission budgets for 2010, 2015,

and after 2020. This established a budget to

accommodate some possible future VMT

growth in the area.

As they look ahead to planning for attainment, several other areas expressed the belief

that their mobile source budgets will need to

be increased. It is unclear, however, how this

would occur as overall budgets continue to

shrink and areas begin planning for the new

NAAQS. A few areas suggested trying to

negotiate a shift of emissions from area source

budgets to mobile sources, realizing that area

sources have been regulated much less than

stationary sources in the past and present a

much less cohesive and powerful lobby.

Conformity Effects on SIP TCMs

To ensure that nonattainment areas actually implement TCMs written into SIPs, the

conformity regulations require that implementation of SIP TCMs proceed according to

the schedule in the SIP. Although the conformity rule does not require areas to put

TCMs in the SIP, some environmentalists believed that the protection given SIP TCMs

would encourage areas to do so. During the

initial round of SIP planning, however, conformity proved to be a disincentive for inclusion of TCMs in SIPs. Most areas decided

that placing TCMs in the SIP would be too

risky because delay of a SIP TCM could cause

a conformity lapse, jeopardizing the flow of

federal funding for all transportation projects.

This feeling was especially intense in areas like

Boston and Philadelphia that had experienced

problems with TCMs in previous SIPs. Given

the risks, the small emission reduction benefits

of most TCMs, and the reality that reductions

from TCMs were not necessary to meet the

SIP emission reduction goals or conformity,

five of the study areas chose not to include any

TCMs in their 15% SIPs or maintenance plans.

Most other areas included only a few TCMs,

the majority of which were TSM projects that

they regarded as certain to be implemented on

schedule.10

10As discussed earlier in this chapter, all areas

have included some form of TCMs in their transportation plans/programs, even if they have not written

them into SIPs.
Chapter 5: Conformity Effects on Transportation and Air Quality Plans 93

There were a few exceptions, however.

San Francisco was required, as a result of the

MTC suit, to include a number of TCMs in its

redesignation request. These were carried

forward from its 1982 SIP and were augmented with new TCMs in the contingency

plan. In Chicago, planners included more than

100 TCMs in the 15% SIP, believing that any

TCMs credited in the conformity analysis

should be in the SIP; however, these were

primarily traffic flow improvement measures

that were deemed certain to stay on track for

implementation. In New Jersey, the state

DOT proposed including 136 TCMs in the

15% SIP, believing that they would help the

area reach its air quality goals. Only later did

transportation planners realize that by placing

TCMs in the SIP, they helped ratchet the

budget down, making conformity more

difficult. Although NJDOT originally believed

it had included only TCMs that were secure,

implementation of some was later held up,

with the result that the air agency requested

that EPA postpone final approval of the TCMs

in the SIP. Now neither the state DOT, nor

the air quality agency has any desire to place

TCMs in future SIPs.

Portland is the only study area that placed

TCMs in the SIP specifically to ensure their

implementation. Facing regular challenges in

the legislature on the state growth management law, the area included its urban growth

boundary and related transit measures in the

SIP to protect them from possible changes in

the political climate.

Several areas expressed the belief that issuance of promised federal guidance on TCM

flexibility would make it much easier to place

TCMs in SIPs. Although TCM flexibility was

one of the issues raised by stakeholders during

deliberations over the amendments to the 1993

conformity rule, EPA determined that a rule

change was not necessary to allow areas to

substitute a new TCM for one already in an

approved SIP. EPA pledged to issue federal

guidance on TCM flexibility but had not done

so by the end of the study period. Oregon and

Texas therefore developed their own state

TCM flexibility rules. Air quality planners in

Oregon believe that their TCM flexibility

provisions were instrumental in gaining the

agreements necessary to put TCMs into the

SIP. EPA found the Texas rule unapprovable

but did approve Oregon’s as part of the area’s

1996 ozone maintenance plan.

The most dramatic recent effect of conformity on SIP TCMs occurred in Atlanta,

which is pursuing a strategy of adding TCMs

to the SIP.11 Also, the air agency planned voluntary ozone action days, both to help demonstrate attainment and to aid conformity. In

December 1997, Governor Miller strengthened

this measure by signing an executive order that

required state employees to reduce single

occupant trips by 20% on ozone action days.

Other SIP Impacts 

ADDITIONAL CONTROL MEASURES. Although some areas considered the ramifica11The November 1995 amendments to the 1993

conformity rule allow SIP TCMs to proceed during a

lapse. EPA believes that in the future this provision

may offset some of the disincentive that the timely

implementation requirement creates for placing TCMs

in the SIP.
Chapter 5: Conformity Effects on Transportation and Air Quality Plans 94

tions of conformity when choosing SIP measures other than TCMs, few adopted mobile

source control measures that were not mandated by the CAAA. In Arizona, however, the

state legislature, which was deeply involved in

selecting the measures that comprised the

Phoenix 15% VOC reduction SIP, wanted to

offset emissions growth that would occur as

the area continued to build highways.

Legislators therefore explicitly chose to

implement mobile source technology measures

more stringent than federally mandated for

moderate ozone areas, such as enhanced inspection and maintenance and more stringent

Reid Vapor Pressure standards for fuel.

As implementation of the conformity rule

progressed, some study areas considered SIP

amendments that would expand or strengthen

I/M to ease difficulties passing the conformity

tests. In Denver, when the area faced conformity problems in 1996, an agreement was

reached through interagency consultation to

tighten the I/M cut points to make passing

conformity easier. By decreasing the amount

of NOx emissions cars would be allowed under

the I/M program in 2001, budget test problems

for 2015 were resolved. Most areas, however,

decided against such a strategy, given the high

level of controversy encountered in many

states over the I/M program. For example,

although the Texas legislature had initially

delegated authority to the Governor for

decisions regarding the I/M program, it

subsequently passed a law that enabled the air

agency to expand I/M to additional counties

only if they requested to be included in the

program. Because none volunteered,

consideration of expanded I/M in the Houston

area came to a halt.

In Baltimore, although conformity did not

influence the initial form or extent of the I/M

program, it did help to protect I/M from legislative action that would have made the program voluntary. If the program had become

voluntary, EPA would have disapproved the

area’s SIP, and conformity of the transportation plan/TIP would have been frozen.

The governor vetoed the voluntary I/M bill

after he was made aware of these ramifications.

In Atlanta, where conformity problems are

closely linked with difficulties demonstrating

attainment, planners proposed adoption in the

SIP of a new mobile source control, “Georgia

fuel,” which by reducing future emissions

would contribute to resolving the area’s

difficulties.

NOX TRADES AND WAIVERS. Two study

areas, Baltimore and Salt Lake City, considered stationary source/mobile source NOx

trades as a way of dealing with conformity

problems; however, neither found it necessary

to follow through with their plans. When Salt

Lake City faced NOx conformity problems in

1994 due to the change from MOBILE 4 to

MOBILE 5, the area considered a NOx trade.

One of the major stationary sources had

recently modernized and, as a result, had a

permit for unused emissions. It agreed to sell

these outside the area to compensate for the

higher mobile source NOx emissions generated

by MOBILE 5 in the conformity analysis. The

need for this trade was alleviated when EPA

allowed the area to continue using MOBILE 4

for PM10 NOx conformity.

As the Baltimore area faced the aspect of

setting its first NOx budget in 1996, trans-
Chapter 5: Conformity Effects on Transportation and Air Quality Plans 95

portation and air quality planners feared that

they would have difficulty passing the NOx

budget test. The MPO had just completed a

new household travel survey, which was expected to show substantial NOx

 increases. The

air agency therefore suggested writing a clause

in the SIP that would allow it to trade stationary source NOx

 credits if it encountered a

minor mobile source shortfall in the conformity

analysis. The MPO hesitated to agree to this

plan and the issue became moot when the new

data showed NOx emissions to be substantially

lower than previous levels. 

Three study areas, Chicago, Houston and

Phoenix, requested NOx waivers, at least in

part to avoid problems with the conformity

NOx build/no-build tests. Chicago and Phoenix were given waivers because they were able

to demonstrate that NOx reductions would not

contribute toward their efforts to reach

attainment. Houston’s NOx waiver was temporary, pending the outcome of a study to determine whether the area was NOx

 limited.

When the waiver permanently expired at the

end of 1997, the area was uncertain how it

would pass future NOx budget tests.

MITIGATION MEASURES OUTSIDE OF THE

SIP. Denver adopted air quality measures

outside of the SIP to pass conformity, while

avoiding the hurdles of an amendment to add

measures to the SIP. As a part of its strategy

for dealing with its PM10 problems, Denver’s

MPO negotiated agreements with municipal

governments to implement non-regulatory

street sanding and sweeping measures that are

credited in the conformity analysis, even

though they are not in the SIP.
LINKING TRANSPORTATION AND AIR QUALITY PLANNING:

IMPLEMENTATION OF THE 

TRANSPORTATION CONFORMITY REGULATIONS 

IN 15 NONATTAINMENT AREAS

Arnold M. Howitt and Elizabeth M. Moore

Taubman Center for State and Local Government

John F. Kennedy School of Government

Harvard University

March 1999

A Report to the

U.S. Environmental Protection Agency

and the

Federal Highway Administration,

U.S. Department of Transportation

Publication Number

EPA420-R-99-011

CHAPTER 6: TOWARD A NEW PLANNING “ARENA”
Chapter 6

TOWARD A NEW PLANNING “ARENA”

Among conformity’s purposes was to establish an institutional and procedural framework – a new planning “arena” – within which

the set of state and regional agencies and

stakeholders concerned with transportation

and air quality would organize their many

policy interactions. Although securing compliance with Clean Air Act mandates was a

presumed minimum requirement, some observers expected that conformity – combined

with other innovations prescribed by ISTEA,

such as regular updating and fiscal constraint

of regional plans – would have more farreaching impacts. More and better demographic, economic, land use, travel, and air

quality data would be gathered and evaluated

with sharper analytic tools. Agencies and

stakeholders would articulate and openly discuss their goals, propose alternative policies to

achieve them, assess feasibility and tradeoffs,

and consider whether and how to implement

them. The improved planning process, in turn,

would inform public discussion of transportation and air quality issues and provide a

stronger basis for deliberation by appointed

policy makers and elected officials. 

Given the historic separation of these domains, this was an ambitious set of expectations. In conclusion, therefore, it is well worth

focusing on whether and how much conformity has contributed to creating such a planning

arena in the 15 study sites and what limitations

exist.

Better Data and Analytic Tools

The interviews conducted for this study reveal a broad professional consensus that, at

least in the study sites, conformity-related improvements in planning methods are genuine

and valuable not only for air quality regulation

but also for other planning purposes. 

A few individuals pointed to the opportunity costs of conformity-induced modeling

enhancements, arguing that they come at the

expense of other potential changes in analytic

practice, especially more extensive analysis of

alternative planning scenarios. This outcome

results not so much because these practices are

mutually incompatible but because limited time

and resources make it difficult or impossible to

do both. 

But most individuals interviewed for the

study believe that the conformity requirement

that transportation planners use advanced analytic tools and the latest available planning

assumptions to forecast transportation demand

and mobile source emissions – coupled with

the infusion of ISTEA funds to hire technical

staff and collect more recent, often more

detailed, data about demographic trends, land

use, and travel behavior – has led to significant

improvements in planning capabilities in all of

the study sites, though in varying degrees.

Moreover, one might expect these changes to

have increased impact as they are used and refined in successive planning cycles.
Chapter 6: Toward a New Planning “Arena” 97

Although enhanced modeling and planning

methods might eventually have been adopted

as a result of ISTEA planning requirements

alone, most transportation planners

interviewed for the study believe that conformity pushed technical planning changes

significantly faster than would otherwise have

happened. A number of environmentalists,

however, expressed impatience with the scope

and pace of these changes, arguing that MPOs

often took too long to implement changes and

have not gone far enough in adopting new

methods. Transportation planners asserted, in

turn, that the advocates underestimated the

difficulty of instituting change, especially in the

context of the sweeping scope of new ISTEA

planning requirements.

While the balance between these views is

arguable in any particular situation, it seems

more striking that across the study sites the direction of change is consistent, even if the results are not equal in all cases. Interviews for

this study strongly suggest that the culture of

transportation planning, which at the working

level had previously given little attention to air

quality, has been significantly affected.

Improvements in transportation modeling and

the principle that air quality impacts should be

taken into account by transportation planners

are widely accepted by transportation planners.

Improvements in transportation planning

have served not only to focus transportation

planners on the goals and requirements of the

Clean Air Act but also have had a direct effect

on air quality planning. Improved forecasts of

VMT, the finer detail achieved through

technical enhancements, and the increased

frequency of the regional analysis provide air

planners with a better understanding of the

geographic distribution of transportation

impacts and changes over time. New planning

tools have thus been deployed to achieve far

greater integration of transportation and air

quality analysis than previously existed. In

several areas, air quality planners have

capitalized on the modeling improvements by

incorporating VMT estimates from the travel

demand models into the budget setting

process. Most agree that using the same VMT

growth assumptions in the budgets and the

analysis of transportation plans/programs

better integrates transportation and air quality

planning and creates a more valid comparison

for conformity. Use of the improved models

and data also enhances the air quality planning

process by giving air planners information

helpful in selecting appropriate and sufficient

SIP measures.

Analysis and the Regulatory

Process

It is important to distinguish, however, between acceptance of air quality analysis for

planning purposes as opposed to regulatory

purposes. Conformity shapes policy decisions

that affect air pollution, mobility, economic

development, and quality of life in the

metropolitan areas in this study. Large sums of

federal aid – as well as legal authority to

proceed with projects using that money – are

also at stake in the process. As a result, many

transportation and air planners continue to

have significant differences about how the

conformity analysis is conducted and what

impacts it has on the quality of decision making. 
Chapter 6: Toward a New Planning “Arena” 98

While most transportation planners in

MPOs and state DOTs regard the results as

valuable for thinking about transportation and

air quality “futures” and the possible effects of

alternative policies, some resent the absolute

priority that air quality goals have over all

other goals in transportation planning. Many,

moreover, question the validity of using the

model outputs for making conformity

determinations, arguing that conformity conveys an alarmingly false image of precision.

These planners point to baseline estimates that

at best approximate actual conditions, the

plausible range of assumptions about future

rates of change in key variables, the known imperfections of even state-of-the-art transportation demand models, the acknowledged shortcomings of the emission models, and the

incompatibility of model structures that makes

it analytically problematic to use the output of

the demand models as input for the emission

models. Many transportation planners

therefore express deep skepticism about using

current modeling techniques, which taken together have a wide band of possible error, to

make long-range forecasts of future pollution

– especially when these results are used for a

threshold regulatory test in conformity potentially affecting the flow of large amounts of

federal funds for their plans and projects.

These feelings are sometimes intensified

because of inconsistencies between the planning assumptions incorporated in SIPs and

those in the conformity analysis. Not all areas

have used the outputs of travel demand models

for estimating transportation emissions in their

SIP development process, particularly during

the initial years after the CAAA of 1990 was

enacted. Moreover, because the conformity

regulations require transportation planners to

use the latest planning data and assumptions

available, the data and assumptions used for

conformity may differ significantly from those

used – perhaps a few years earlier – in developing a pertinent SIP.

Inconsistencies between the data and planning assumptions in a SIP and a later conformity analysis do not always make it more

difficult to demonstrate conformity. Indeed,

sometimes the assumptions embedded in SIPs

make it easier to conform a transportation plan

than would be the case if the SIP were updated. But if the reverse is true, transportation

planners often express frustration that the

complexities and slowness of the state regulatory and federal approval processes make it

quite time consuming – and often impractical

within the time frame of regular transportation

planning cycles – to update SIP planning

assumptions.

By contrast, many air planners and environmental advocates, while acknowledging

some shortcomings, contend that the modeling

results used in conformity analysis provide a

sufficiently good approximation of current

reality and future development patterns to

warrant their use for conformity, especially

given their view that it is critically important to

achieve Clean Air Act goals. Others argue

that emission models underestimate mobile

source pollution, so that transportation

projects get the benefit of the doubt. Some

suspect that MPOs shade the transportation

demand analysis to produce favorable results.
Chapter 6: Toward a New Planning “Arena” 99

Another divergence in the perspectives of

transportation and air planners on the regulatory process deserves mention. Conformity

permits the modeling to take “credit” for improvements in vehicle emission control systems or beneficial changes in fuel composition

only when these are mandated by federal

regulations and/or adopted in legally enforceable regulations by the state.

Many transportation planners and advocates regard this as an artificial feature of the

planning system. They contend that it is poor

policy to be forced to forgo what they regard

as transportation improvements which would

otherwise be permissible simply because the

time frame of decision making on national

technology policies is independent of – and

therefore imperfectly synchronized with – the

timing of their conformity decisions.

For example, a nonattainment area may be

experiencing serious conformity problems

while, simultaneously, significant changes in

national regulation of automobile emission

control systems and fuels may be under debate

and likely to have major impacts on mobilesource emissions during the time frame of the

conformity analysis. For example, while Charlotte has been experiencing a conformity lapse,

there has been intense national discussion of

the Tier II controls, possible extension of controls to new vehicle types (e.g., to sports utility vehicles), and possible changes in the sulfur

content of gasoline.1 

Many air agencies and environmental advocates argue that until such controls are legally mandated, it is inappropriate for conformity to recognize still-speculative emission

reductions. Once transportation projects are

approved, they are difficult or impossible to

reverse if emission reductions from technology

measures do not materialize.

Confronting Conformity Difficulties

In the framework of the CAAA of 1990,

conformity is an analytic “trip-wire” to alert

policy makers to inconsistencies between two

sets of policies – air quality planning (codified

in state implementation plans) and transportation planning (codified in transportation

plans and programs). Indeed, in many instances, conformity results in serious reconsideration of evolving mobile-source emission issues more quickly than would occur through

periodic SIP revisions alone. 

In the 15 study sites, this reconsideration

tends to occur in distinct phases. First, planners carefully re-examine the modeling on

which the conformity analysis is based to confirm that a problem exists and to discover its

magnitude. When conformity difficulties are

significant, they must then deal with the institutional and political dynamics of changing

either the transportation plan/program or the

applicable SIP so that conformity can be

demonstrated.

1

It should be noted, however, that these controls

would not affect Atlanta’s conformity problems, which

arise from an inability to demonstrate conformity in

1999, its ozone attainment year.
Chapter 6: Toward a New Planning “Arena” 100

Re-examining the Models

When an MPO encounters difficulties in

showing that its transportation plan or program satisfies the requirements of conformity,

the most common initial response, as Chapters

3 and 4 have shown, is exhaustive re-examination of modeling data, methods, and results.

Through the process of reconsidering planning assumptions and modeling techniques, the

transportation agencies seek to reduce the

possibility that conformity penalties might

result from “technical” difficulties in the modeling rather than “real” future problems revealed by conformity forecasting of emissions.

Environmental agencies, in turn, seek to

discover whether the analysis has been

conducted appropriately and whether genuine

conformity problems exist. As a result of such

scrutiny on both sides, errors have been discovered, improved estimates of key parameters have been secured, and refinements of

modeling methods have been introduced. 

The character of consultation and stakeholder participation appears to have important

consequences for the credibility and longer

term effects of the analytic process.

In areas with less intense interagency consultation practices, reassessment of modeling

methods is likely to be performed primarily by

MPO staff, sometimes with little visibility to

other agencies and stakeholders. In a number

of these cases, as described in Chapter 4, air

agencies and environmental advocacy groups

lack sufficient staff resources or technical skills

to participate actively and effectively scrutinize

the MPO’s work. But MPO autonomy comes

at a cost: reduced confidence by outsiders in

the results. The opacity of the process tends

to increase suspicions that the MPO’s interest

in “passing” the conformity tests has colored

its analysis.

By contrast, when the analytic issues of

conformity have been the focus of careful “upfront” discussion and debate among interested

agencies and stakeholders, either early in the

planning cycle or in previous cycles, reconsideration is more likely to be an open process.

While sometimes contentious and not always

fully eliminating doubts on either side, these

efforts have nonetheless tended to strengthen

confidence in the results. Transportation

planners are more likely to regard any remaining problems in demonstrating conformity

as “real” rather than modeling artifacts; and air

planners and advocacy groups are less likely to

harbor suspicions that conformity has been

demonstrated by technical manipulation.

As successive cycles of conformity analysis

are undertaken, effective interagency consultation creates greater mutual confidence in the

analytic process. In turn, this allows both sets

of planners and other stakeholders to focus

more clearly on substantive issues and policy

choices rather than on disputes about modeling. 

Generating Policy Debate

Conformity was also clearly intended to

get policy officials, elected executives, legislators, and a broad array of stakeholder groups

to confront the policy dimensions and
Chapter 6: Toward a New Planning “Arena” 101

tradeoffs of transportation and air quality.

Nonetheless, data from the 15 study sites suggests that it can sometimes be problematic to

move discussion of conformity problems beyond the relatively small circle of transportation and air quality professionals and the few

stakeholder representatives who deal with it on

a regular basis. In some of the study areas,

this has led to considerable delay in confronting the roots of their conformity problems.

As discussed in Chapter 4, the complexity

of conformity modeling and analysis can be a

barrier for less technically sophisticated

participants. This has been a problem in areas

like Charlotte and Atlanta, where, encountering severe conformity problems, the transportation and air quality professionals have

spent a year or more probing the models and

analysis, looking for technical fixes to the

problem, but only slowly getting high-level officials and the public to address the underlying

issues. Thus, the expectation of conformity

architects that public debate would be spurred

by conformity problems has been partially

frustrated by the technical nature of -

conformity discussions. 

It is not the case that public discussion is

suppressed. Denver’s experience with PM10

conformity difficulties demonstrates that vigorous policy debate can develop as an area wrestles with its conformity problems. Similar

public debates have emerged in Atlanta and

Charlotte during 1998 (a period outside the

time frame of this study). In these instances,

the causes, consequences, and possible solutions of the area’s air quality and transportation difficulties have gotten a good deal of

public attention, including from key elected

leaders. 

Nonetheless, there seems to be a substantial lag period as conformity difficulties move

from a primarily bureaucratic setting that

involves a small number of technical personnel

from public agencies (and perhaps similar

people from a few private groups) to a more

visible, public policy process that addresses the

underlying issues and debates options and

tradeoffs.

The Institutional Dynamics of

Changing Transportation and

Air Quality Plans

In the event of conflict between transportation plans and air quality commitments, the

conformity regulations permit an MPO or

state, in principle, to resolve the inconsistency

by making changes to its transportation

plans/programs, its SIPs, or both. To resolve

a conformity problem, an area might choose to

make changes in transportation plans/programs

(e.g., by dropping, scaling back, or exploring

alternatives to major highway capacity

expansion projects, or by adding air quality

beneficial projects). Alternatively, policy makers might decide in a given case that it made

sense to add new mobile source control

measures to the SIP (e.g., fuel requirements or

a strengthened inspection and maintenance

system) or to make tradeoffs between mobileand other sources.

Giving nonattainment areas flexibility in

deciding how to meet national pollution standards was a key element of the underlying

philosophy of the 1990 Clean Air Act Amendments. As a practical matter, however, it has
Chapter 6: Toward a New Planning “Arena” 102

often proven more difficult to make such changes than some of the architects of conformity

anticipated.

Many environmental advocates and air

planners have been frustrated that the transportation planning/programming process has

proven less pliable than they hoped or expected. MPOs are not autonomous, hierarchical,

executive-driven decision-making bodies; and

project selection is not the result of a small

group of policy makers acting at a single

decision point. Instead, MPOs build policy

and political consensus on the projects that

comprise transportation plans through bargaining and negotiation, over extended periods

of time, among diverse interests inside and

outside of government. To disaggregate the

final package of projects that appear in a

regional transportation plan or program is

therefore politically arduous and time consuming. 

This problem is exacerbated by the weak

link between transportation planning and land

use regulation that exists in virtually all of the

study sites. Although conformity must take

account of the likely outcomes of land use

regulation, the core regional and state agencies

responsible for conformity – the MPO, the air

agency and the state DOT – generally have no

direct authority over land use decision making

and regulation. So development projects

independently initiated by local governments

or private developers may create pressures for

transportation improvements that have the

potential to cause conformity difficulties. 

Even where MPOs have land use planning

responsibilities, which not all of them do have,

they do not have land use regulatory authority

– with the exception among the study sites of

Portland’s Metro. Local and county governments typically wield this power – and these

entities are not direct participants in conformity except through their representation on the

MPO board.

From the transportation side, therefore, it

frequently seems attractive to resolve conformity difficulties by seeking changes on the

air quality side – i.e., in the state implementation plan. But this path encounters other kinds

of difficulties.

Although legally required practices vary, in

many states revising a SIP may necessitate not

only a process of drafting and internal agency

clearance by legal counsel and policy officials

but also public hearings and adoption by some

form of environmental regulatory board.

Depending on the state, this may take many

months, sometimes more than a year. During

the study period, moreover, SIP amendments

also had to be reviewed and approved by EPA

before they could be used in conformity

determinations. This frequently took longer

than a year. The August 1997 conformity

amendments are intended to reduce this aspect

of the problem by permitting nonattainment

areas to use a newly submitted emission

budget after 45 days instead of waiting for

formal EPA approval of the budget.

This time frame for SIP revision is rarely

compatible with the rhythms of the transportation planning process, which is often connected to an annual cycle of project programming and the triennial long-range planning process required by ISTEA. To go through the
Chapter 6: Toward a New Planning “Arena” 103

SIP revision process is almost always to delay

the normal schedule for developing and

initiating new plans/programs. 

Seeking changes in a SIP is also burdensome for air planners. They often have competing priorities for time and resources, including meeting new SIP development responsibilities. Not unlike the political process that

produces transportation plans, emission budgets usually represent consensus policies established after long periods of negotiation

among stakeholders from different emissionsource sectors. Reopening budget allocation

decisions can ignite politically potent intersectoral disputes. Air planners are therefore

often reluctant to manage SIP revisions. Given these facts, it is not surprising as Chapter 5

reported, that making SIP changes was not a

common approach to solving conformity problems in the 15 study sites.

While changing plans is difficult on both

sides, it is ultimately transportation plans that are

placed at risk by conformity difficulties. This

was clearly intended by the legislative architects

of the conformity provision of the CAAA of

1990. Federal transportation funding is a large,

politically significant sum in most states. A

threat to its use is a way of getting attention

from policy makers and many stakeholder

groups that a problem exists in transportation

and air quality plans. Whether or not the

solution lies on the transportation side – and

what that solution ought to be – may be less

important than getting decision makers and

constituencies focused on the air quality problem

and searching for a solution.

But it is also true that the officials with direct responsibilities for the program at risk – in

MPOs and state DOTs – have direct influence

over only some of the potential ways of

resolving inconsistencies between

transportation and air quality plans. Air

planners have far less incentive to consider SIP

changes. To the extent, therefore, that

conformity is meant to allow even-handed consideration of the means of resolving

inconsistencies between transportation and air

quality plans, the difficulties in changing SIPs

and the disparities in the timing of the two

planning processes is problematic. It will be

instructive to see whether the August 1997

conformity amendments make a material difference in the way nonattainment area policy

makers seek to resolve conformity difficulties.

Conformity as an Evolving Process

This study is a snapshot of conformity during

a particular period, but like any regulatory

process conformity is evolving and responding

to new situations. In addition to the issues noted

in this chapter, conformity must adapt to the

new National Ambient Air Quality Standards for

ozone and particulate matter, which will make

new areas subject to regulation. New tools for

analyzing transportation demand and the effects

of transportation policies on pollution are in

development. The impact of conformity over

the long run on transportation planning/programming may be greater than it has been to date – as

new plans and projects take account of

conformity in their formative stages, not just as

they are being finalized.

EPA and FHWA, the sponsors of this study,

are planning a second phase to follow these

developments, which will certainly warrant analysis to measure progress and identify problems.
LINKING TRANSPORTATION AND AIR QUALITY PLANNING:

IMPLEMENTATION OF THE 

TRANSPORTATION CONFORMITY REGULATIONS 

IN 15 NONATTAINMENT AREAS

Arnold M. Howitt and Elizabeth M. Moore

Taubman Center for State and Local Government

John F. Kennedy School of Government

Harvard University

March 1999

A Report to the

U.S. Environmental Protection Agency

and the

Federal Highway Administration,

U.S. Department of Transportation

Publication Number

EPA420-R-99-011

APPENDIX I: GLOSSARY OF ABBREVIATIONS
Appendix I

GLOSSARY OF ABBREVIATIONS

TERMS:

CMAQ Congestion mitigation and air quality

CO Carbon monoxide

ECO Employee Commute Options

EMFAC California motor vehicle emissions model

HOV High occupancy vehicle

HPMS Highway Performance Monitoring System

I/M Inspection and maintenance

ISTEA Intermodal Surface Transportation Efficiency Act

LEV Low emission vehicle

LUTRAQ Land Use, TRansportation, and Air Quality study conducted in Portland

MIS Major investment study

MOBILE EPA motor vehicle emissions model

NAAQS National Ambient Air Quality Standards

NEPA National Environmental Policy Act

NOx Nitrogen oxides

NPRM Notice of proposed rulemaking

PM10 Particulate matter smaller than or equal to 10 micrometers

RCAP Regional commuter assistance program

RFG Reformulated gasoline

RFP Reasonable further progress

ROP Rate of progress

RTP Regional transportation plan

RVP Reid vapor pressure

SIP State implementation plan

SOV Single occupancy vehicle

STIP State transportation improvement program

TCM Transportation control measures

TDM Transportation demand management

TIP Transportation improvement program

TSM Transportation systems management

UAM Urban airshed model

VMT Vehicle miles traveled

VOCs Volatile organic compounds

AGENCIES:

ABAG Association of Bay Area Governments (San Francisco area)

ARC Atlanta Regional Commission

BMC Baltimore Metropolitan Council

Caltrans California Department of Transportation

CATS Chicago Area Transportation Study
Appendix I: Glossary of Abbreviations 105

CDPHE Department of Public Health and Environment (Colorado)

CTPS Central Transportation Planning Staff (Boston MPO staff)

DEC/EnCon Department of Environmental Conservation (New York State)

DENR Department of Environment and Natural Resources (North Carolina)

DEP Department of Environmental Protection

DNR Department of Natural Resources

DRCOG Denver Regional Council of Governments

DVRPC Delaware Valley Regional Planning Commission (Philadelphia area)

EDF Environmental Defense Fund

EOTC Executive Office of Transportation and Construction (Massachusetts)

EPA Environmental Protection Agency

FHWA Federal Highway Administration

FTA Federal Transit Administration

GDOT Georgia Department of Transportation

H-GAC Houston-Galveston Area Council

IDOT Illinois Department of Transportation

MARTA Metropolitan Atlanta Rapid Transit Authority

Metro Metropolitan Service District (Portland area)

MDE Maryland Department of Environment

MDOT Maryland Department of Transportation

MTC Metropolitan Transportation Commission (San Francisco area)

NJDEP New Jersey Department of Environmental Protection

NJTPA New Jersey Transportation Planning Authority

NYMTC New York Metropolitan Transportation Council

OTAG Ozone Transport Assessment Group

PennDOT Pennsylvania Department of Transportation

SEWRPC Southeastern Wisconsin Regional Planning Commission

TxDOT Texas Department of Transportation

TNRCC Texas Natural Resources Conservation Commission

USDOT US Department of Transportation

USEPA US Environmental Protection Agency

WFRC Wasatch Front Regional Council (Salt Lake City area)

WisDOT Wisconsin Department of Transportation
LINKING TRANSPORTATION AND AIR QUALITY PLANNING:

IMPLEMENTATION OF THE 

TRANSPORTATION CONFORMITY REGULATIONS 

IN 15 NONATTAINMENT AREAS

Arnold M. Howitt and Elizabeth M. Moore

Taubman Center for State and Local Government

John F. Kennedy School of Government

Harvard University

March 1999

A Report to the

U.S. Environmental Protection Agency

and the

Federal Highway Administration,

U.S. Department of Transportation

Publication Number

EPA420-R-99-011

APPENDIX II: CONFORMITY PROFILES OF 15 STUDY SITES
Appendix II

CONFORMITY PROFILES OF 15 STUDY SITES

ATLANTA

Pollutant(s):

Ozone

1990 Classification:

Serious

Geographic Boundaries of Ozone Nonattainment Area:

13 Counties: Cherokee, Clayton, Cobb, Coweta, DeKalb, Douglas, Fayette, Forsyth, Fulton, Gwinnett,

Henry, Paulding and Rockdale.

Geographic Boundaries of MPO Area:

10 Counties: Cherokee, Clayton, Cobb, DeKalb, Douglas, Fayette, Fulton, Gwinnett, Henry, and

Rockdale.

Year: Nonattainment

Area Population:

Average

Daily VMT:

Percent

Annual

Population

Growth:

Percent Annual

Average Daily

VMT Growth:

 

Average Daily

VMT/Capita:

1980 1,989,341

1990 2,653,159 81,472,984 2.9%b 30.7

1995 3,038,050 105,218,456a2.8%c 4.4% d 34.6e

a1996 C1990-1995 e

 Per capita rates are calculated using 1995 population and 1996 VMT.

b1980-1990 d1990-1996 

Key Institutions:

MPO: Atlanta Regional Commission (ARC)

State Transportation Agency: Georgia Department of Transportation (GDOT)

State Air Agency: Georgia Department of Natural Resources (DNR) 

Summary of Conformity Issues:

1995 – ARC began implementing model and data upgrades that captured higher emission levels than had been

reflected in earlier analyses. As a result, Atlanta barely passed the NOx budget test. 

1996 – Passing the budget test proved even more problematic than it had in 1995. Because the area was

experiencing higher than expected VMT growth and was slow to implement inspection and maintenance and

reformulated gasoline programs, its 1999 NOx budget for ozone set an emissions cap that the area could not

meet in developing a new TIP. ARC, the Atlanta MPO, and Georgia DOT struggled to develop strategies that

would close the large gap between allowable and projected emissions. Ultimately, the northern arc of the Outer

Loop was barred from moving into the TIP, the road to the massive new Mall of Georgia was scaled back, and

only exempt and grandfathered projects from the previously conformed 1995 TIP were allowed to move forward.

1997- Difficulties continued throughout 1997 during which ARC could not develop a new long-range plan that

conformed. In August 1997, FHWA granted a six-month TIP extension, during which a controversy over

grandfathering projects surfaced. Not able to develop a full conforming TIP, the MPO drafted an interim TIP

(ITIP) that contained only TCMs written into SIPs that had received EPA approval, as well as grandfathered
Appendix II: Conformity Profiles of 15 Study Sites 107

1

In addition, it recognized the need for national-level staff of EPA, FHWA, and FTA to develop a national memorandum of understanding or make changes in the conformity regulations to ensure proper use of the grandfathering

provision, particularly to see that it was not used to evade the consequences of a conformity lapse.

and exempt projects from the 1995 regional transportation plan update. Several dozen projects that ARC originally wanted to regard as grandfathered were not ultimately included in the ITIP because FHWA felt they

could not meet the applicable NEPA requirements; EPA simultaneously reviewed the NEPA documents.

FHWA’s regional office was then prepared to approve the ITIP, but EPA’s regional office raised concerns

about several of the remaining grandfathered projects in the ITIP.

This led to sharp policy disagreements among the federal agencies. Even though the 1995 plan had received

a conformity determination, EPA’s regional office argued that the conformity analysis had not satisfied all of

the applicable requirements of the conformity rule. EPA therefore believed that the disputed projects should

not be grandfathered because they would ultimately substantially increase highway capacity, worsening air

quality problems. Staff from the White House Council on Environmental Quality ultimately brokered a regional-level agreement among EPA, FHWA, and FTA that allowed five of six disputed projects to move forward

in the ITIP, with two of these limited to planning and design. ARC removed the sixth project from the ITIP.

The EPA-FHWA-FTA agreement also established dates by which the Atlanta area should complete a

conforming long-range plan and an ozone attainment demonstration.1 Conformity lapsed in Atlanta on January

17, 1998.
Appendix II: Conformity Profiles of 15 Study Sites 108

BALTIMORE

Pollutant(s):

Ozone

Carbon Monoxide

1990 Classification:

Severe 1

Moderate 2 (Redesignated to Attainment 1995)

Geographic Boundaries of Ozone Nonattainment Area:

6 Counties: Anne Arundel, Baltimore, Baltimore City, Carroll, Harford, and Howard.

Geographic Boundaries of MPO Area: 

6 Counties: Anne Arundel, Baltimore, Baltimore City, Carroll, Harford, and Howard.

Year: Nonattainment

Area Population:

Average

Daily VMT:

Percent Annual

Population

Growth:

Percent Annual

Average Daily

VMT Growth:

Average Daily

VMT/Capita:

1980 2,173,989

1990 2,348,219 49,900,000 0.8%a 21.3

1995 2,432,993 55,900,000 0.7%b 2.3%b 23.0

a1980-1990 b1990-1995

Institutions:

MPO: Baltimore Metropolitan Council (BMC)

State Transportation Agency: Maryland Department of Transportation (MDOT)

State Air Agency: Maryland Department of the Environment (MDE)

Summary of Conformity Issues:

1993 – During Interim Conformity, the Chesapeake Bay Foundation and the Environmental Defense Fund

jointly challenged the MPO’s modeling practices. This temporarily delayed the area’s conformity determination.

1995 – The Sierra Club Legal Defense Fund questioned the MPO’s use of emission reductions from the ECO

program to pass the build/no-build test because ECO had been made voluntary and its funding had been cut

by the legislature. The MPO therefore dropped ECO from the conformity analysis and substituted a regional

commuter assistance program that it developed and pledged to fund and implement in 2005. 

1996 – The Sierra Club Legal Defense Fund again raised issues with the conformity determination, questioning

whether Baltimore could claim full emission reduction credit for the enhanced I/M program, which had not yet

been implemented. EPA, however, advised that the conformity analysis should be calculated assuming

implementation of the measures in the submitted SIP, whether or not they were moving forward on time.

1997 – The Maryland legislature passed a bill to make the I/M program voluntary. The Governor vetoed this

bill at least in part because of the conformity implications of failing to implement the required form of I/M. If

the program had become voluntary, EPA would have disapproved the SIP and conformity of the transportation

plan/TIP would have been frozen.
Appendix II: Conformity Profiles of 15 Study Sites 109

BOSTON

Pollutant(s):

Ozone

Carbon Monoxide

1990 Classification:

Serious

Moderate 2 (Redesignated to Attainment 1996)

Geographic Boundaries of Ozone Nonattainment Area:

9 Counties: Barnstable, Bristol, Dukes, Essex, Middlesex, Norfolk, Plymouth, Suffolk, and Worcester. (But

study focused only on geographic area congruent with that of the Boston MPO.)

Geographic Boundaries of MPO Area:

The Boston MPO covers 101 towns and cities within the larger ozone nonattainment area.

Year: Nonattainment

Area

Population:

Average

Daily VMT:

Percent Annual

Population

Growth:

Percent Annual

Average Daily

VMT Growth:

 Average

Daily

VMT/Capita:

1980 4,945,835

1990 5,204,103 59,816,200 0.5%b 11.5

1995 5,274,317 64,412,700a 0.4%c 1.2%d12.2e

a1996 c1990-1995 e

Per capita rates are calculated using 1995 population and 1996 VMT.

b1980-1990 

d1990-1996

Institutions:

MPO: Boston MPO, staffed by the Central Transportation Planning Staff (CTPS)

State Transportation Agency: The Executive Office of Transportation and Construction (EOTC)

State Air Agency: Massachusetts Department of Environmental Protection (DEP)

Summary of Conformity Issues:

1994 – Boston could not pass the build/no-build tests for CO, NOx and VOCs, due to an error in a spreadsheet

supplied to CTPS by DEP for the conformity analysis. The conformity determination was delayed for about

two months while the agencies discovered and corrected the problem.

Conformity was also held up in 1994 over fiscal constraint issues. During the approval process for the FY

1995-97 STIP, FHWA’s Massachusetts division office cited two fiscal constraint problems. First, FHWA

believed that the second year of the STIP (FY 1996) was 100% over-programmed because the state had

budgeted the sum of its highway apportionments, plus its unobligated balance. Second, the state was counting

on money from a bond bill not yet approved by the legislature to fund a major project during the first two years

of the STIP. FHWA and FTA therefore deferred approval of the STIP pending resolution of these issues.

Although highway funding was held-up and TIP conformity could not proceed, this was not technically a

“conformity lapse,” having been caused by a funding dispute between FHWA and the state over the STIP.

1995 – When trying to conform the FY 96-98 TIP, CTPS encountered problems with the build/no-build test for

NOx, VOCs and CO due to a technicality in the way the conformity analysis is calculated. These problems arose

because, for some milestone years, the build and no-build scenarios were the same. For example, in analysis of the

1996 milestone year, FY 96 was in both the no-build scenario (because it had already been conformed in the FY 95-

97 TIP) and the build scenario. Because there had been no substantial, regionally significant changes made to

projects, the analysis showed no decrease in emissions in the build scenario, which is required by the conformity rule.

To solve the problem, CTPS added a CMAQ project to the TIP and did an off-model analysis to pass the test. 
Appendix II: Conformity Profiles of 15 Study Sites 110

1997 – The Boston metropolitan region could not pass the NOx build/no-build test due not to road projects but

to high NOx emissions from diesel commuter trains. However, because the nonattainment area encompasses

the entire eastern half of the state, Boston’s conformity analysis is combined with those of nine other MPOs.

When Boston’s NOx emissions were averaged across the entire nonattainment area, passing the NOx build/nobuild test was not a problem. 
Appendix II: Conformity Profiles of 15 Study Sites 111

CHARLOTTE

Pollutant(s):

Ozone

Carbon Monoxide

1990 Classification:

Moderate (Redesignated to Attainment 1995)

Not Classified (Redesignated to Attainment 1995)

Geographic Boundaries of Ozone Nonattainment Area:

2 Counties: Mecklenburg and Gaston.

Geographic Boundaries of MPO Area:

2 Counties: Mecklenburg and Union.

Year: Nonattainment

Area Population:

Average

Daily VMT:

Percent Annual

Population

Growth:

Percent Annual

Average Daily

VMT Growth:

Average Daily

VMT/Capita:

1980 566,838

1990 686,574 14,515,000 1.9%a 21.1

1995 760,939 18,442,000 2.0%b 4.9%b 24.2

a1980-1990 b1990-1995

Institutions:

MPO: Mecklenburg/Union MPO, staffed by the Charlotte Department of Transportation

State Transportation Agency: North Carolina Department of Transportation (NCDOT)

State Air Agency: Department of Environment and Natural Resources (DENR) 

Summary of Conformity Issues:

1994 – During its first conformity determination under the 1993 conformity rule, the area found that future

VOC and NOx emission projections derived from the transportation plan were higher than the emission budgets

in the ozone maintenance plan. Planners at the state air agency believed that the higher emissions in the transportation plan were due not to an actual increase in pollution, but to the difference between the methods used

to calculate VMT in the base year for the emission budgets (using HPMS and other data) and that used to develop the new transportation plan (using the MPO’s travel demand models). To rectify this problem, the area

developed a reconciliation methodology that applied a corrections factor to the base-year inventories to make

them comparable to the 1990 emission levels in the transportation plan. The air agency argued that once the

difference in the base-year VMT calculations was reconciled, the area should conform if the emissions growth

rate in the transportation plan stayed below the growth rate in the maintenance plan. Although the area passed

conformity in 1994 using this methodology, EPA subsequently required that the area develop a technique that

adjusted base-year VMT to match the SIP’s base-year emissions inventory rather than vice versa, as any

adjustments applied to the budget would require a SIP amendment. The state and MPO subsequently

accomplished this.

1996 – In 1995, the MPO had decided that a conformity analysis was not required since the projects in the new

TIP came from a conforming plan and had not undergone any major changes. Later in the year, however, the

air agency discovered an error in its emission budget calculations. When the error was corrected and the new,

much lower budgets were used in the 1996 conformity analysis, the area showed substantial exceedances of

both the VOC and NOx emission budgets, especially for the 2005 and 2015 analysis years. Charlotte continued

to move forward grandfathered and exempt projects while the MPO, state DOT, and state air agency worked

at the staff level to find a solution to this thorny problem. 
Appendix II: Conformity Profiles of 15 Study Sites 112

1997 – Charlotte’s conformity lapsed in January 1997. The area had enough grandfathered projects to continue

building through the year with only three projects being held up by the conformity lapse. In late 1997, under

pressure from the backers of one of the stalled projects, the Governor directed the transportation and air quality

agencies to do whatever was necessary to resolve the lapse. However, by the end of the study period no

resolution was forthcoming.
Appendix II: Conformity Profiles of 15 Study Sites 113

CHICAGO

Pollutant(s):

Ozone

PM10

1990 Classification:

Severe 2

Moderate

Geographic Boundaries of Ozone Nonattainment Area:

8 Counties: Cook, Du Page, Grundy (Only Aux Sable and Goose Lake Townships), Kane, Kendall (Only

Oswego Township), Lake, McHenry, and Will. 

Geographic Boundaries of MP0 Area:

7 Counties: Cook, Du Page, Kane, Kendall (Only Oswego Township), Lake, McHenry, and Will. 

Year: Nonattainment

Area

Population:

Average

Daily VMT:

Percent Annual

Population

Growth:

Percent Annual

Average Daily

VMT Growth:

 Average

Daily

VMT/Capita:

1980 7,171,420

1990 7,332,926 127,402,856 0.2%a 17.4

1995 7,641,329 140,834,243 0.4%b 2.0%b 18.4

a1980-1990 b1990-1995

Institutions:

MPO: Chicago Area Transportation Study (CATS)

State Transportation Agency: Illinois Department of Transportation (IDOT)

State Air Agency: Illinois Environmental Protection Agency (IEPA)

Summary of Conformity Issues:

1994 – Chicago had begun a conformity analysis under the interim guidance; however, by the time it went to

public comment in early 1994, the 1993 final conformity rule was in effect. During the comment period, US

EPA and a coalition of local environmental groups, aided by technical experts affiliated with EDF, questioned

the validity of the VMT growth rates predicted in the CATS travel demand models. These were significantly

lower than the VMT generated from IDOT’s HPMS data that had been used to set the budgets. CATS

developed a supplemental conformity submittal that documented and explained its modeling procedures. This

was ultimately accepted by the federal agencies; however, FHWA required CATS to improve its modeling for

future conformity determinations. 

During the 1994 analysis, Chicago had difficulty passing the NOx build/no-build test. The situation was

resolved when transportation planners realized they could take credit for new alternative fuel buses through

off-model analysis. The area subsequently applied for a NOx waiver, which was granted in 1996. 

1995 – Chicago had to forgo a conformity analysis in 1995, as the required upgrades to its network models had

not yet been completed. The area therefore had to delay implementation of some projects, advancing only those

that were grandfathered and exempt until the next conformity cycle.
Appendix II: Conformity Profiles of 15 Study Sites 114

DENVER

Pollutant(s):

Ozone

Carbon Monoxide

PM10

1990 Classification:

Transitional

Moderate (reclassified to Serious 1997)

Moderate

Geographic Boundaries of Ozone Nonattainment Area:

6 Counties: Adams, Arapahoe, Boulder, Denver, Douglas, and Jefferson.

Geographic Boundaries of MPO Area: 

8 Counties: Adams, Arapahoe, Boulder, Clear Creek, Denver, Douglas, Gilpin, and Jefferson.

Year:

Nonattainment

Area

Population:

Average

Daily VMT:

Percent Annual

Population

Growth:

Percent Annual

Average Daily

VMT Growth:

 Average

Daily

VMT/Capita:

1980 1,618,461

1990 1,848,319 39,100,000 1.3%b 21.2

1995 2,085,158 50,900,000a 1.7%c 4.5%d 24.4e

a1996 c1990-1995 ePer capita rates are calculated using 1995 population and 1996 VMT.

b1980-1990 d1990-1996

Institutions:

MPO: Denver Regional Council of Governments (DRCOG)

State Transportation Agency: Colorado Department of Transportation (CDOT)

State Air Agency: Colorado Department of Public Health and Environment (CDPHE)

Lead Agency for SIP Planning: Regional Air Quality Council (RAQC)

Summary of Conformity Issues:

1993 – Denver did not have difficulty satisfying the requirements of the interim conformity guidance.

However, in anticipation of a more stringent final federal conformity rule, environmental advocacy groups

strongly criticized a non-federal project proposed by a public toll authority. The advocacy groups feared that

this project, the E-470 segment of a circumferential roadway, would open new land to development, creating

more PM10 emissions than planners were forecasting. The transportation agencies also had concerns about

emissions from this project and sought assurances that E-470 would not jeopardize the area’s ability to

demonstrate conformity in the future. Project sponsors eventually agreed to certain specific mitigation

measures and created an escrow fund to finance additional mitigation, if that proved necessary.

1994 – During the conformity analysis of the 1994 TIP, transportation planners could not demonstrate that

emissions in the final horizon year of the transportation plan (2015) would stay below the 1997 PM10 budget

of 44 tpd in the maintenance plan. The area lapsed for almost a year and advanced only grandfathered and

exempt projects while it undertook the difficult and contentious task of amending the PM10 budgets. Working

together, transportation and regional air quality planners determined that the regional PM10 emissions budget

could be raised from 44 to 60 tpd – without either imposing new controls on stationary and area sources or

causing violations of the NAAQS. This could be accomplished by adopting mitigation measures that would

reduce 2015 emissions to the 60 tpd level in the Denver core, while allowing the permissible level of PM10
Appendix II: Conformity Profiles of 15 Study Sites 115

emissions to rise to the 60 tpd level in the suburban areas of the region. This proposal provoked months of

controversy and criticism from environmental and public health advocates regarding the health effects of

increased particulate levels. The state environmental agency approved this increase for only three years, which

would have created conformity problems later on. The state legislature intervened to permit the increase for

the full SIP period. The area was then able to conform the plan and TIP in 1995.

1996 – Denver had difficulties in 1996 demonstrating conformity for the annual TIP revision. Having

upgraded its transportation demand modeling, DRCOG found additional amounts of forecasted VMT and hence

higher levels of PM10 emissions from re-entrained dust and from NOx precursors of PM10. To resolve the PM10

problems, DRCOG negotiated agreements with local governments to alter their street sanding and sweeping

practices to reduce the dust kicked up by automobiles. To deal with the NOx problems the air agency, after

discussions with stakeholders, committed to lower I/M NOx cut-points after 2001.

In 1996, Denver area environmentalists raised fiscal constraint issues during the conformity process. Arguing

that the MPO was mitigating emissions from the E-470 tollway project by claiming credit for transit expansion

projects that did not have secure funding, they threatened to sue on the grounds that the plan was not adequately

fiscally constrained. The MPO counter-argued that the emission benefits of the transit projects were so small

that the projects could be totally removed from the plan without threatening the conformity determination.

Ultimately, no litigation was filed, and there was no delay in the conformity determination.
Appendix II: Conformity Profiles of 15 Study Sites 116

HOUSTON

Pollutant(s):

Ozone

1990 Classification:

Severe

Geographic Boundaries of Ozone Nonattainment Area:

8 Counties: Brazoria, Chambers, Fort Bend, Galveston, Harris, Liberty, Montgomery, and Waller 

Geographic Boundaries of MPO Area:

13 Counties: Austin, Brazoria, Chambers, Colorado, Fort Bend, Galvston, Harris, Liberty, Matagorda,

Montgomery, Walker, Waller, and Wharton.

Year: Nonattainment

Area

Population:

Average 

Daily VMT:

Percent Annual

Population

Growth:

Percent Annual

Average Daily VMT

Growth:

Average

Daily

VMT/Capita:

1980 3,118,480

1990 3,731,029 90,400,000 1.8%a 24.2

1995 4,164,393 105,800,000 2.0%b 3.2%b 25.4

a1980-1990 b1990-1995

Institutions:

MPO: Houston-Galveston Area Council (HGAC)

State Transportation Agency: Texas Department of Transportation (TxDOT)

State Air Agency: Texas Natural Resources Conservation Commission (TNRCC)

Summary of Conformity Issues:

1994 - Houston had difficulty passing the VOC budget test. As a result of this, and also due to fiscal

constraint difficulties, the large Grand Parkway project was scaled back and spread out over several years.

In 1994, Houston was also unable to pass the build/no-build test for NOx for ozone and, as a result, conformity

was delayed while waiting for a NOx waiver.

1995 - Houston was granted a temporary NOx waiver until 1997.

1997 - Houston attempted its first conformity analysis using a 1999 VOC budget which tightened the

emissions cap from the 1996 budget level. The conformity analysis showed that at the end of the twenty year

planning horizon, Houston would not be below the 1999 levels for VOCs. By switching to modeled VMT

estimates rather than HPMS VMT and by correcting for an over-estimation of VMT on local streets, the area

revised the budgets and demonstrated conformity.
Appendix II: Conformity Profiles of 15 Study Sites 117

MILWAUKEE

Pollutant(s):

Ozone

1990 Classification:

Severe 2

Geographic Boundaries of Ozone Nonattainment Area:

6 Counties: Kenosha, Milwaukee, Ozaukee, Racine, Washington, and Waukesha.

Geographic Boundaries of MPO Area:

7 Counties: Kenosha, Milwaukee, Ozaukee, Racine, Walworth, Washington, and Waukesha.

Year: Nonattainment 

Area

Population:

Average

Daily

VMT:

Percent Annual

Population

Growth:

Percent Annual

Average Daily

VMT Growth:

 Average

Daily

VMT/Capita:

1980 1,693,289

1990 1,735,364 33,072,000 0.2%a 19.1

1995 1,780,769 35,900,000 0.3%b 1.7%b 20.2

a1980-1990 b1990-1995

Institutions:

MPO: Southeastern Wisconsin Regional Planning Commission (SEWRPC)

State Transportation Agency: Wisconsin Department of Transportation (WisDOT)

State Air Agency: Wisconsin Department of Natural Resources (DNR)

Summary of Conformity Issues:

The most significant conformity issue which confronted the Milwaukee area was passing the build/no-build

tests, but this never caused the area a major problem or delay in making its conformity determinations. The

Milwaukee area was helped in dealing with conformity by the results of a broad-based SIP planning task force

was established through which all actors came to the table (including both public and private interests from

mobile, stationary, and area sources) to evaluate various strategies for reducing emissions within each source

category; to consider carefully the trade-offs among mobile, stationary and area source controls, and thus to

set budgets with an understanding of their future implications.

1995 - Milwaukee was saved from a conformity lapse by the February 1995 conformity amendments which

increased the time for areas to submit complete SIPs to two years, effectively aligning the SIP conformity lapse

with imposition of CAAA highway sanctions.
Appendix II: Conformity Profiles of 15 Study Sites 118

NORTHERN NEW JERSEY

Pollutant(s):

Ozone

Carbon Monoxide

1990 Classification:

Severe 2

Moderate 2

Geographic Boundaries of Ozone Nonattainment Area:

11 Counties: Bergen, Essex, Hudson, Hunterdon, Middlesex, Morris, Ocean, Passaic, Somerset, Sussex, and

Union.

Geographic Boundaries of MPO Area:

13 Counties: Bergen, Essex, Hudson, Hunterdon, Middlesex, Monmouth, Morris, Ocean, Passaic, Somerset,

Sussex, Union, and Warren.

Year: Nonattainment

Area Population:

Average

Daily VMT:

Percent Annual

Population

Growth:

Percent Annual

Average Daily

VMT Growth:

Average

Daily

VMT/Capita:

1980 4,961,510

1990 5,108,929 125,153,923 0.3%b 24.5

1995 5,243,598 129,352,902a 0.4%c 0.6%d 24.7e

a1999 c1990-1995 e

 Per capita rates are calculated using 1995 population and 1999 VMT

b1980-1990 d1990-1999 predictions.

Institutions:

MPO: North Jersey Transportation Planning Authority (NJTPA)

State Transportation Agency: New Jersey Department of Transportation (NJDOT)

State Air Agency: New Jersey Department of Environmental Protection (NJDEP)

Summary of Conformity Issues:

The most significant conformity issue which confronted the northern New Jersey area was passing the

build/no-build tests, but this never resulted in a serious problem or delay in making the area’s conformity

determination. 

In regard to the modeling requirements of conformity, NJTPA, a relatively new MPO, received help from

NJDOT and New Jersey Transit. The creation of the model was a public process with significant contribution

from environmental advocates. In northern New Jersey, advocacy groups affiliated with the Tri-State

Transportation Campaign, supported by staff from the Rutgers Environmental Law Center, have actively participated in area transportation planning. They began pushing for technical upgrading of transportation

modeling during the interim conformity period and sought public access to conformity consultations.

1997 - Due to the delayed implementation of New Jersey’s enhanced I/M program, in December of 1997 EPA

declared a conformity freeze, effective the following April. Without implementation of enhanced I/M, New

Jersey’s previously conditionally accepted SIP was revoked and the state was unable to demonstrate the

necessary 15% reduction of VOC. This freeze continued into 1999 as the state revised the 15% VOC SIP and

worked to implement its I/M program.
Appendix II: Conformity Profiles of 15 Study Sites 119

NEW YORK

Pollutant(s):

Ozone

Carbon Monoxide

PM10

1990 Classification:

Severe 2

Moderate 2

Moderate

Geographic Boundaries of Ozone Nonattainment Area:

10 Counties: Bronx, Kings, Nassau, New York, Orange, Queens, Richmond, Rockland, Suffolk, and

Westchester.

Geographic Boundaries of MPO Area:

10 Counties: Bronx, Kings, Nassau, New York, Putnam, Queens, Richmond, Rockland, Suffolk and

Westchester.

Year:

Nonattainment

Area Population:

Average

Daily VMT:

Percent Annual

Population

Growth:

Percent Annual

Average Daily

VMT Growth:

Average Daily

VMT/Capita:

1980 11,063,184

1990 11,379,764 133,577,052 0.3%a 11.7

1995 11,462,260 132,284,161 0.2%b-0.2%b, c 11.5

a1980-1990 b1990-1995 cNYMTC does not regard the negative VMT rate for this period as indicative of 

 future trends.

Institutions:

MPO: New York Metropolitan Transportation Council (NYMTC)

State Transportation Agency: New York State Department of Transportation (NYSDOT)

State Air Agency: New York State Department of Environmental Conservation (DEC or EnCon)

Summary of Conformity Issues:

1994 - New York demonstrated conformity using qualitative analysis and sketch planning techniques.

1995 - New York did not have the required network model in operation by the January deadline. The region

advanced only exempt and grandfathered projects in 1995. New York’s inability to develop the required

modeling capacity stemmed in part from a state-mandated hiring freeze, which made adding technical staff

or outside consultants impossible.

1996 - The network based models continued to be non-operational through 1996. To compensate, the area

sought and received a third-year extension of its 1994 TIP, continuing to advance only exempt and grandfathered projects.

1997 - An interim network model was approved and New York was able to complete the required conformity

analysis to adopt a new TIP.
Appendix II: Conformity Profiles of 15 Study Sites 120

PHILADELPHIA

Pollutant(s):

Ozone

Carbon Monoxide

1990 Classification:

Severe 1

Moderate 1 (Redesignated to Attainment 1996)

Geographic Boundaries of Ozone Nonattainment Area:

5 Counties: Bucks, Chester, Delaware, Montgomery, and Philadelphia.

Geographic Boundaries of MPO Area:

9 Counties: Bucks, Chester, Delaware, Montgomery, and Philadelphia counties in Pennsylvania;

Burlington, Camden, Gloucester, and Mercer in New Jersey.

Year:

Nonattainment

Area

Population:

Average

 Daily VMT:

Percent

Annual

Population

Growth:

Percent

Annual

Average Daily

VMT Growth:

Average Daily

VMT/Capita:

1980 3,682,450

1990 3,728,991 64,565,000 0.1%b 17.3

1995 3,731,703 70,195,000a 0.0%c 1.4%d 18.8e

a1996 

C1990-1995 ePer capita rates are calculated using 1995 population and 1996 VMT.

b1980-1990 d1990-1996

Institutions:

MPO: Delaware Valley Regional Planning Commission (DVRPC)

State Transportation Agency: Pennsylvania Department of Transportation (PennDOT)

State Air Agency: Pennsylvania Department of Environmental Protection (DEP)

Summary of Conformity Issues:

The most significant conformity issue which confronted the Philadelphia area was passing the build/no-build

tests, but this never caused the area a major problem or delay in making its conformity determinations.

1995 - Philadelphia was saved from a conformity lapse by the February 1995 conformity amendments which

increased the time for areas to submit complete SIPs to two years, effectively aligning the SIP conformity lapse

with imposition of CAAA highway sanctions.
Appendix II: Conformity Profiles of 15 Study Sites 121

2Ozone nonattainment area only includes those parts of Maricopa county which are included in the Maricopa

Association of Governments (MAG).

PHOENIX

Pollutant(s):

Ozone

Carbon Monoxide

PM10

1990 Classification:

Moderate (Reclassified Serious in 1997)

Moderate (Reclassified Serious in 1996)

Moderate (Reclassified Serious in 1996)

Geographic Boundaries of Ozone Nonattainment Area:

2 Counties: Maricopa2 and Pinal. 

Geographic Boundaries of MPO Area:

1 County and Two Tribal Communities: Maricopa County, the Gila River Indian Community, the Salt

River Pima Maricopa Indian Community.

Year:

Nonattainment

Area

Population:

Average

Daily

VMT:

Percent Annual

Population

Growth:

Percent Annual

Average Daily

VMT Growth:

Average Daily

VMT/Capita:

1980 1,600,093

1990 2,238,498 49,600,000 3.4%a 22.2

1995 2,563,582 57,000,000 3.2%b 2.8%b 22.2

a1980-1990 b1990-1995

Institutions:

MPO and Lead Agency for SIP Development: Maricopa Association of Governments (MAG)

State Transportation Agency: Arizona Department of Transportation (ADOT)

State Air Agency: Arizona Department of Environmental Quality (DEQ)

Summary of Conformity Issues:

1994 - Realizing that it would not be able to pass the build/no-build test for NOx as a precursor to ozone,

Phoenix applied for a NOx waiver. This application process delayed the area’s conformity determination by

several months during which time MAG advanced only exempt and grandfathered projects. Phoenix was

eventually granted a permanent waiver for NOx.

1995 - Model enhancements to the area’s existing network model briefly delayed conformity determination.

MAG obtained the assistance of outside consultants for several years in order to improve its modeling

capability. 
Appendix II: Conformity Profiles of 15 Study Sites 122

PORTLAND

Pollutant(s): 1990 Classification:

Ozone Marginal (Redesignated to Attainment 1997)

Carbon Monoxide Moderate 1 (Redesignated to Attainment 1997)

Geographic Boundaries of Ozone Nonattainment Area:

3 Partial Counties: Clackamas, Multnomah, and Washington. 

Geographic Boundaries of MPO Area:

3 Counties: Clackamas, Multnomah, and Washington.

Year:

Nonattainment

Area

Population:

Average

Daily VMT:

Percent Annual

Population

Growth:

Percent Annual

Average Daily

VMT Growth:

 Average

Daily

VMT/Capita:

1980 1,050,418

1990 1,174,291 20,413,000 1.1%a 17.4

1995 1,300,729 22,437,000 1.4%b 1.9%b 17.2

a1980-1990 b1990-1995

Institutions:

MPO: Metropolitan Service District (Metro)

State Transportation Agency: Oregon Department of Transportation (ODOT)

State Air Agency: Oregon Department of Environmental Quality (DEQ)

Summary of Conformity Issues:

1994 - Portland experienced difficulties in interpreting the build/no-build requirements and as a result, the

MPO incorrectly assigned projects to the baseline and action scenarios, invalidating the conformity analysis.

When the mistakes were uncovered, the area decided to let conformity lapse for a year rather than expending

the resources to re-do the analysis. All current projects were either exempt or grandfathered and therefore not

affected by the conformity lapse.

1996- In developing its 1996 ozone attainment demonstration/maintenance plan, Portland took a proactive

approach to future conformity determinations by setting emissions budgets for ozone precursors for the years

beyond the milestone year of the maintenance plan. Quantifying its safety margin between total emissions in

the attainment year (1992) and 2006, it gradually allocated part of its safety margin to create somewhat larger

mobile source emission budgets for 2010, 2015, and 2020. This established a budget to accommodate some

possible future VMT growth in the area.

Portland placed TCMs in the SIP specifically to ensure their implementation. Other areas were reluctant to

place numerous TCMs into their SIPs as their presence could trigger a lapse of conformity if the area could

not demonstrate timely implementation. Facing regular challenges in the legislature on the state growth

management law, Portland included its urban growth boundary and related transit measures in the SIP to

protect them from possible changes in the political climate.
Appendix II: Conformity Profiles of 15 Study Sites 123

SALT LAKE CITY

Pollutant(s):

Ozone

Carbon Monoxide

PM10

1990 Classification:

Moderate (Redesignated to Attainment 1997)

Not Classified

Moderate

Geographic Boundaries of Ozone Nonattainment Area:

2 Counties: Davis and Salt Lake.

Geographic Boundaries of MPO Area:

5 Counties: Davis, Morgan, Tooele, Salt Lake, and Weber.

Year:

Nonattainment

Area

Population:

Average

Daily VMT:

Percent Annual

Population

Growth:

Percent Annual

Average Daily

VMT Growth:

 Average

Daily

VMT/Capita:

1980 765,606

1990 913,897 20,130,479 1.8%b 22.0

1995 1,023,7659 25,864,357a 2.0%c 4.3%d 25.3e

a1996 c1990-1995 ePer capita rates are calculated using 1995 population and 1996 VMT.

 

b1980-1990 d1990-1996

Institutions:

MPO: Wasatch Front Regional Council (WFRC)

State Transportation Agency: Utah Department of Transportation (UDOT)

State Air Agency: Utah Department of Environmental Quality (DEQ)

Summary of Conformity Issues:

1993 - Salt Lake City submitted an attainment demonstration and maintenance plan for ozone rather than put

forth a 15% SIP. Conformity was frozen until the SIP was found complete.

1994 - The area had difficulty passing the NOx budget test for PM10. This was partially due to the region’s

previous SIP for PM10which had been developed in the late 1980’s before the budget concept for pollutants

or the conformity procedures. Additionally, the city’s previous budget for NOx had used MOBILE 4 while the

conformity analysis mandated MOBILE 5, which calculated much higher emissions from mobile sources. The

area’s conformity lapsed from November 1994 to October 1995. Advancing only grandfathered and exempt

projects, the area tried to convince EPA that the budget problem was not the result of real increases in

emissions but of differences in the way MOBILE 4 and MOBILE 5 projected NOx emissions. EPA was eventually persuaded and has since allowed the Salt Lake City area to use MOBILE 4 in the conformity analysis

for NOx (as a precursor of PM10, but not of ozone).

In 1994, the area was also unable to show that at the end of the 2005 planning horizon the city would be within

the approved levels for NOx for ozone. To correct this situation, the area extended the maintenance plan to

2015. By adding ten years to the budget, the area was able to demonstrate that, without adding any additional

control measures to the SIP, NOx emissions could rise after the first ten years of the plan without causing a

violation of the NAAQS.

1995 - With the extended plan for ozone maintenance, the area was able to demonstrate conformity and has

not experienced conformity problems since that time.
Appendix II: Conformity Profiles of 15 Study Sites 124

SAN FRANCISCO

Pollutant(s):

Ozone

Carbon Monoxide

1990 Classification:

Moderate (Redesignated to Attainment 1995, Proposed

Reclassification to Nonattainment, 1997)

Moderate 1(Redesignated to Attainment 1998)

Geographic Boundaries of Ozone Nonattainment Area:

9 Partial Counties: Alameda, Contra Costa, Marin, Napa, San Francisco, San Mateo, Santa Clara, Solano,

and Sonoma.

Geographic Boundaries of MPO Area:

9 Counties: Alameda, Contra Costa, Marin, Napa, San Francisco, San Mateo, Santa Clara, Solano, and

Sonoma.

Year:

Nonattainment

Area

Population:

Average

Daily VMT:

Percent Annual

Population

Growth:

Percent Annual

Average Daily

VMT Growth:

Average Daily

VMT/Capita:

1980 5,179,759

1990 6,020,147 113,389,000 1.5%a 18.8

1995 6,302,933 123,666,900 1.3%b 1.8%b 19.6

a1980-1990 b1990-1995

Institutions:

MPO: Metropolitan Transportation Commission (MTC)

State Transportation Agency: California Department of Transportation (Caltrans)

State Air Agency: California Environmental Protection Agency (CalEPA)

Joint SIP Development Responsibility: Bay Area Air Quality Management District (BAAQMD),

Association of Bay Area Governments (ABAG), and MTC

Summary of Conformity Issues:

1989- The Sierra Club Legal Defense and other environmental advocates brought a litigation challenge to

MTC’s modeling practices. The extensive model upgrades that MTC instituted as a result of settling the suit

influenced the national politics reflected in the conformity requirements, and they positioned MTC to meet

those requirements once 1993 regulations were promulgated.

1996 - In accordance with the settlement of a previous suit, MTC was obligated to incorporate into its ozone

maintenance plan several TCMs which originated in the area’s 1982 SIP. Due to the imprecise definitions of

some of those TCMs, the BAAQMD and the EPA regional office questioned their timely implementation. In

response, MTC supplied more detailed descriptions of the TCMs and the timelines for their implementation.

MTC’s response satisfied the air district and EPA that the conformity requirement was being met.
LINKING TRANSPORTATION AND AIR QUALITY PLANNING:

IMPLEMENTATION OF THE 

TRANSPORTATION CONFORMITY REGULATIONS 

IN 15 NONATTAINMENT AREAS

Arnold M. Howitt and Elizabeth M. Moore

Taubman Center for State and Local Government

John F. Kennedy School of Government

Harvard University

March 1999

A Report to the

U.S. Environmental Protection Agency

and the

Federal Highway Administration,

U.S. Department of Transportation

Publication Number

EPA420-R-99-011

APPENDIX III: INTERVIEW SUBJECTS BY STUDY SITE
Appendix III

INTERVIEW SUBJECTS BY STUDY SITE

ATLANTA

Atlanta Regional Commission

Patti Schropp, Transportation Planning Division

Denise Wright, Transportation Planning Division

Jane Davis Hayse, Transportation Planning Division

Wayne Hill, ARC Member; Chair, Gwinnett County Board of Commissioners

Georgia Department of Transportation

Frank Danchetz, Chief Engineer

Georgia Department of Natural Resources

Ron Methier, Chief, Air Protection Branch, Environmental Protection Division

Metro Atlanta Chamber of Commerce

Jeff Rader, Transportation Coordinator

Georgia Power Company

Chris Hobson, Manager of Environmental Affairs

Myles Smith, Manager, Urban Affairs Department

Environmental Defense Fund

Michael Replogle, Co-Director, Transportation Project

Georgia Conservancy

Eric Meyer, Environmental Policy Analyst

Automobile Association of America

Ted Allred, Regional Director

Federal Highway Administration

Bob Radics, Intermodal Planning Engineer Manager, Georgia Division

John Humeston, Director, Planning and Program Development, Region 4

U.S. Environmental Protection Agency

Eric Maurer, Environmental Engineer, Mobile Source Planning Unit, Air Programs

Branch, Region 4

Kay Prince, Chief, Regulatory Planning Section, Air Planning Branch, Region 4

Kelly Sheckler, Environmental Scientist, Air Planning Branch, Region 4
Appendix III: Interview Subjects by Study Site 126

BALTIMORE

Baltimore Metropolitan Council

Harvey Bloom, Director of Transportation

John Wing, Chair, Citizen’s Advisory Committee

Steven Horn, Member, Transportation Steering Committee (the MPO); Chief of Planning,

Carroll County Board of Commissioners

Maryland Department of Transportation

Missy Drissel Cassidy, Manager, Air Quality Planning, Office of Systems Planning and

Evaluation

Fred Rappe, Director, Systems of Planning and Evaluation

Rick Sheckells, Manager, Air Quality Planning, Office of Systems Planning and Evaluation

Howard Simons, Systems Analyst, Office of Systems Planning and Evaluation

Maryland Department of the Environment

Diane Franks, Chief, Air Quality Planning, Air and Radiation Management Administration

Environmental Defense Fund

Michael Replogle, Co-Director, Transportation Project

Federal Highway Administration

Mario Jorquera, Air Quality Specialist, Region 3

Michelle Waxman-Johnson, Transportation Planner, Maryland Division

U.S. Environmental Protection Agency

Paul Wentworth, Environmental Engineer, Ozone and Mobile Sources Section, Region 3

BOSTON

Metropolitan Area Planning Council

Dan Fortier, Chief Transportation Planner

Central Transportation Planning Staff

Craig Leiner, Manager of Certification Activities

Anne McGahan, Senior Planner

Karl Quackenbush, Deputy Technical Director of Operations

Executive Office of Transportation and Construction 

Dan Beagan, Director, Bureau of Transportation Planning and Development

Massachusetts Bay Transportation Authority

Andrew Brennan, Manager of Environmental Affairs

Anne Galbraith, Deputy Director of Planning
Appendix III: Interview Subjects by Study Site 127

Executive Office of Environmental Affairs

Sonia Hamel, Director of Air Policy and Planning

Massachusetts Department of Environmental Protection

Christine Kirby, Manager, Transportation Planning Unit, Division of Air Quality Control

Conservation Law Foundation

Steve Burrington, Senior Attorney

Federal Highway Administration

Ed Silva, Planning and Research Engineer, Massachusetts Division

U.S. Environmental Protection Agency

Donald Cooke, Environmental Scientist, Region 1

CHARLOTTE

City of Charlotte Department of Transportation

William Finger, Assistant Director of Transportation

David McDonald, Transportation Planner

Joseph McLelland, Transportation Planner

North Carolina Department of Transportation

David Hyder, Charlotte Area Coordinator and Air Quality Specialist, Statewide Planning

 Branch

Marion Ron Poole, Branch Manager, Office of Statewide Planning

Department of Environment and Natural Resources

Deidre Hinkle, Environmental Engineer, Air Quality Section

Brock Nicholson, Assistant Chief for Planning, Air Quality Section, Division of

 Environmental Management

North Carolina General Assembly (State Legislature)

George Givens, Staff Attorney, Environmental Review Commission

Sierra Club

Molly Diggins, State Chair

William Holman, Lobbyist

John Tallmadge, Transportation Planner

Environmental Defense Fund

Michael Replogle, Co-Director, Transportation Project

Federal Highway Administration

Kay Batey, Planning and Program Development Engineer, North Carolina Division
Appendix III: Interview Subjects by Study Site 128

Wendy Gasteiger, Environmental Program Specialist, North Carolina Division

John Humeston, Director, Planning and Program Development, Region 4

John Schrohenloher, Planning Engineer, North Carolina Division

Joe Stevens, Planning Engineer, North Carolina Division

U.S. Environmental Protection Agency

Eric Maurer, Environmental Engineer Mobile Source Planning Unit, Air Programs Branch,

Region 4

Kay Prince, Chief, Regulatory Planning Section, Air Planning Branch, Region 4

Kelly Sheckler, Environmental Scientist, Air Planning Branch, Region 4

CHICAGO

Chicago Area Transportation Study

Linda Bolte, Deputy Planning

Andrew Plummer, Deputy Director

Eugene Ryan, Associate Executive Director

Bob Kaiser, Consultant; Senior Project Manager, Michael Baker, Jr., Inc.

Chicago Department of Transportation

Luann Hamilton, Assistant Director of Project Development, Administration and Planning

John Tomczyk, Coordinating Planner II, Planning and Programming

Illinois Department of Transportation

Carla Berroyer, Chief, Urban Program Planning

Illinois Environmental Protection Agency

Toby Frevert, Manager, Air Quality Planning Section, Bureau of Air

Mike Rogers, Environmental Protection Specialist, Bureau of Air

Chicago Transit Authority

Marty Johnson, Vice President, Capital Investment Department

Illinois State Toll Highway Authority

Ralph Wehner, Executive Director

City of Batavia

Jeff Schielke, Mayor

METRA

Jack Groner, Director, Grant Development and Programming

Jerry Hoff, Department Head, General Development

Business and Professional People in the Public Interest

Robert Jones, Attorney
Appendix III: Interview Subjects by Study Site 129

Center for Neighborhood Technology

Jackie Grimshaw, Coordinator

Environmental Law and Policy Center

Robert Michaels, Attorney

Environmental Defense Fund

Michael Replogle, Co-Director, Transportation Project

Robert Johnston, Professor, Department of Environmental Studies, University of

California, Davis

Federal Highway Administration

Steve Call, Planner, Chicago Metropolitan Office

Jon-Paul Kohler, Urban Transportation Engineer, Illinois Division

Samuel Herrera-Diaz, Metropolitan Planning and Air Quality Specialist, Region 5

U.S. Environmental Protection Agency

Patricia Morris, Environmental Scientist, Air and Radiation Division, Region 5

DENVER

Denver Regional Council of Governments

Jeffrey May, Highway and Transit Planning Coordinator

David Pampu, Deputy Executive Director

Office of the Mayor

Theresa Donahue, Deputy Chief of Staff, City and County of Denver

Colorado Department of Transportation

George Gerstle, Section Manager, Air Quality and Cultural Resources

Regional Transportation District

Elizabeth Rao, Project Manager, Planning and Development

Colorado Department of Public Health and Environment

Karen Kudebeh, Conformity Liaison, Air Pollution Control Division

Regional Air Quality Council

Kenneth Lloyd, Executive Director

Colorado Environmental Coalition

Lauren Martens, Environmental Health Coordinator

Norwest Technical Services, Inc.

Dick Watt, Senior Vice President
Appendix III: Interview Subjects by Study Site 130

Spensley and Associates

James Spensley, President

Environmental Defense Fund

Robert Yuhnke, Attorney

Michael Replogle, Co-Director, Transportation Project

Federal Highway Administration

Duwayne Ebertowski, Transportation Planner, Colorado Division

George Osborne, Division Administrator, Colorado Division

Robin Smith, Air Quality, Urban Transportation Planner, Region 8

U.S. Environmental Protection Agency

Jeff Houk, Environmental Engineer Air Program, Region 8

HOUSTON

Houston-Galveston Area Council

Alan Clark, Manager, Transportation Planning

Steve Howard, Program Director

Jacquie Lentz, Chief Air Quality Planner

Lily Wells, Senior Environmental Planner

City of Houston

Charles Frederikson, Deputy, Assistant Director of Public Works

Dewayne Huckabay, Director, Finance and Administration Department, Office of Energy

 Management

Texas Department of Transportation

Roger Beall, Transportation Planner, Transportation Planning and Programming

Caroll Nixon, Transportation Planning Engineer, Houston-Galveston Regional Office

Eddie Shafie, Metropolitan Planning Manager, Transportation Planning and Programming

Texas Natural Resources Conservation Commission

Hazel Barbour, Mobile Source Manager, Air Quality Planning and Assessment Division

Al Giles, Team Leader, Transportation Unit, Mobile Source Section, Air Quality Planning

and Assessment Division

Teresa Hardin Nguyen, Transportation Planner

Bob Reese, Mobile Source Section

Wayne Young, Transportation Planner

Metropolitan Transit Authority (METRO)

Terrence Grant, Manager of Transit Systems Analysis

Gregg Rhodes, Senior Transit Capital Planner

John Sedlak, Assistant General Manager, Capital and Long Range Planning
Appendix III: Interview Subjects by Study Site 131

Linda Smith, Manager of Environmental Policy

Blackburn and Carter

James Blackburn, Environmental Attorney

Greater Houston Partnership

Roger Hoard, Vice President, Chamber of Commerce Division

Office of the Governor

John Howard, Environmental and Natural Resource Policy Director

Allan Rutter, Transportation Policy Director

Sierra Club

George Smith, Air Quality Chair

Federal Highway Administration

George Hadley, Air Quality Specialist, Region 6

Mike Leary, Intermodal Team Leader, Texas Division

U.S. Environmental Protection Agency

Jahanbakhsh Behnam, Air Planning Section, Region 6

Tom Diggs, Chief, Air Planning Section, Region 6

MILWAUKEE

Southeastern Wisconsin Regional Planning Commission

Kenneth Yunker, Assistant Director

Wisconsin Department of Transportation

Joe Crossett, Planning Analyst, Bureau of Environment

Sarah Dunning, Planning Analyst, Bureau of Environment

Jay Waldschmidt, Civil Engineer, Bureau of Environment

Milwaukee County Transit System

Kenneth Warren, Assistant Director

Wisconsin Department of Natural Resources

John Duffe, Transportation Specialist

Robert Lopez, Air Quality Analyst

Federal Highway Administration

Thomas Frank, Planning and Research Engineer, Wisconsin Division

Samuel Herrera-Diaz, Metropolitan Planning and Air Quality Specialist, Region 5
Appendix III: Interview Subjects by Study Site 132

Citizens for a Better Environment

Bill Schaefer, Staff Attorney

U. S. Environmental Protection Agency

Mike Leslie, Mobile Sources, Region 5

Wisconsin Roadbuilders Association

Tom Walker, Executive Director

NORTHERN NEW JERSEY

North Jersey Transportation Planning Authority

Ted Matley, Director of Planning and Information Technology

William Van Dyke, Chair; member, Board of Freeholders (county legislature), Bergen

County

Joel Weiner, Executive Director

Julia Zhou, Manager of Regional and Subregional Modeling

New Jersey Department of Transportation

Dominic Billera, Air and Noise Division

Cheryl Brennan, Section Chief, Air Quality Planning, Bureau of Statewide Planning

Andy Fekete, Manager, Environmental Services, Bureau of Environmental Analysis

James Lewis, Section Chief, MPO Coordination, Bureau of State-Wide Planning

Jack McQuillan, Air and Noise Division

Robert Miller, Section Chief, Bureau of Transportation Corridor Analysis

John Moore, Manager, Statewide Planning

Andrew Swords, Supervising Planner, Transportation, Air Quality Unit, Bureau of

Technical Analysis

New Jersey Department of Environmental Protection

R. Bruce Benton, Bureau of Air Quality Planning

Chris Salmi, Manager, Bureau Chief of Air Quality Planning, Office of Air Quality

 Management

New Jersey Transit

James P. Redeker, Senior Director of Business Planning

Rutgers Environmental Law Clinic 

Therese Langer, Staff Scientist

Environmental Defense Fund

Michael Replogle, Co-Director, Transportation Project

Federal Highway Administration

Lloyd Jacobs, Planning Team Leader, New Jersey Division
Appendix III: Interview Subjects by Study Site 133

Calvin Edgehill, Community Planner, New Jersey Division

U.S. Environmental Protection Agency

Matthew Cairns, Environmental Engineer, Air Programs Branch, Region 2

John P. Walsh, Air Programs Branch Region 2

NEW YORK

New York Metropolitan Transportation Council

Michelle Bager, Associate Transportation Analyst

Raymond Ruggieri, former Executive Director

Larry Malsam, TCC Subregional Staff Director, Region II

New York Metropolitan Transportation Authority

David Anderson, Senior Transportation Planner, Planning Division

William Wheeler, Director of Planning, Policy and Planning Department

New York City Department of Transportation

Peter Fleischer, Director of Policy and Development, Division of Administration

New York State Department of Transportation

Gary R. McKoy, Director, Environmental Analysis Bureau

Norman Schneider, former Assistant Commissioner; Division Director, Passenger and

Freight Safety Divisions

John Zamurs, Associate Environmental Specialist, Environmental Analysis Bureau

New York City Department of Transportation

Peter Fleischer, Director of Policy and Development, Division of Administration

New York City Department of City Planning

Floyd Lapp, Director, Transportation Division

New York Metropolitan Transportation Authority

David Anderson, Senior Transportation Planner, Planning Division

William Wheeler, Director of Planning, Policy and Planning Department

New York State Department of Environmental Conservation

Elizabeth Bartlett, Environmental Engineer

Robert Hampston, former Assistant Commissioner of Environmental Quality

Jim Ralston, Planner

Dave Shaw, Director, Bureau of Air Quality Planning

New York City Department of Environmental Protection

Geraldine Kelpin, Director, Division of Mobile Source Control Policy and Planning,

 Bureau of Air, Noise, and Hazardous Materials
Appendix III: Interview Subjects by Study Site 134

Konheim and Ketcham

Brian Ketchum, Executive Vice President, Environmental Analysis and Planning

Tri-State Transportation Campaign

Janine Bauer, Executive Director

Environmental Defense Fund

Michael Replogle, Co-Director, Transportation Project

James Tripp, General Counsel

Federal Highway Administration

Joseph Rich, Air Quality/Urban Transportation Planner, New York Division

U.S. Environmental Protection Agency

Rudolph Kapichak, Mobile Source Team Leader, Air Programs Branch, Region 2

John Walsh, Air Programs Branch, Region 2

PHILADELPHIA

Delaware Regional Planning Commission

Ronald Roggenburk, Manager, Air Quality Planning

Bob Kaiser, Consultant; Senior Project Manager, Michael Baker, Jr. Inc.

Pennsylvania Department of Transportation

Mike Baker, Chief of Air Quality Section, Center for Program Development

Bob Janecko, Manager, Center for Program Development

Larry Shifflet, Transportation Planner, Center for Program Development

Pennsylvania Department of Environmental Protection

Arleen Shulman, Mobile Source Coordinator, Bureau of Air Quality Control

New Jersey Department of Environmental Protection

Bruce Benton, Bureau of Air Quality Planning

Chris Salmi, Manager, Bureau Chief of Air Quality Planning, Office of Air Quality

 Management

Southeastern Pennsylvania Transportation Authority

Richard Bickel, Director, Long Range Planning

City of Philadelphia

Denise Goren, Deputy Mayor

Clean Air Council

Jason Rash, Staff Attorney

Dennis Winters
Appendix III: Interview Subjects by Study Site 135

The PENJERDEL Council

Collin McNeil, President

Federal Highway Administration

Robert Hall, Supervisory Community Planner, Pennsylvania Division

Mario Jorquera, Air Quality Specialist, Region 3

Joe Werning, Air Quality Specialist, Pennsylvania Division

U.S. Environmental Protection Agency

Larry Budney, Transportation/Air Quality Planner, Ozone/CO and Mobile Sources

 Section, Region 3

PHOENIX

Maricopa Association of Governments

Douglas Eberhart, Air Quality Planning Manager, Transportation Planning Office

Roger Herzog, Engineering Manager, Transportation Planning Office

Barbara Austin Joy, Consultant; Earth Matters Environmental Consulting

City of Phoenix

Jack Tevlin, Deputy City Manager

Arizona Department of Transportation

Pat Cupell, Air Quality Planner

Jess Jarvis, Manager, MPO/COG Team

Arizona Department of Environmental Quality

Ira Domsky, Planning Section Manager, Office of Air Quality

Arizona Center for Law in the Public Interest

David Baron, Assistant Director

Regional Public Transportation Authority

Ken Driggs, Executive Director

Federal Highway Administration

Dennis Mittelstedt, Division Planning and Research Engineer, Arizona Division

U.S. Environmental Protection Agency

Wienke Tax, Environmental Scientist, Mobile Sources Section, Region 9
Appendix III: Interview Subjects by Study Site 136

PORTLAND

Metro

Andy Cotugno, Planning Director

Michael Hoglund, Transportation Planning Manager

Terry Whisler, Senior Transportation Planner

City of Portland

Robert Burchfield, Principal Engineer, Office of Transportation

Elsa Coleman, Deputy Director of Transportation

Douglas MacCourt, Environmental Manager, Office of Transportation, Engineering and

 Development

Clackamas County

Ed Lundquist, Chairman, County Commission

Rod Sandoz, Planner

Oregon Department of Transportation

Vince Carrow, Senior Air Quality/Hazardous Materials Specialist, Environmental Services

Grace Crunican, Director

Steven Lindland, Civil/Environmental Engineer, Environmental Services

David Williams, Interim Planning and Development Manager, Region 1

Oregon Department of Environmental Quality

John Kowalczyk, Air Quality Division 

Annette Liebe, Manager SIP Section, Air Quality Division

Tri-County Metropolitan Transit District of Oregon

G.B. Arrington, Director, Strategic and Long Range Planning

1000 Friends of Oregon

Keith Bartholomew, Staff Attorney

Cascade Policy Institute

John Charles, Environmental Policy Director

HDR Enginnering, Inc.

Irvin Lloyd, Transportation Projects Environmental Manager

Illingworth and Rodkin

James Reyff

Oregon Economic Development Department

James M. Whitty, Industry Development Division Manager
Appendix III: Interview Subjects by Study Site 137

Federal Highway Administration

Fred Patton, Division Transportation Planner, Oregon Division

Lisa Hanf, Air Quality Specialist/Metropolitan Planner, Region 10

U.S. Environmental Protection Agency

Wayne Elson, Region 10

SALT LAKE CITY

Wasatch Front Regional Council

Kip Billings, Transportation Engineer

Mick Crandall, Program Director

Matt Riffkin, former Planner; Consultant, Fehr and Peers Associates, Inc.

Utah Department of Transportation

Elden Bingham, Air Quality Coordinator, Office of Program Development

John Njord, Engineer for Urban Planning, Office of Program Development

Utah Department of Environmental Quality

Steven Arbaugh, Environmental Health Scientist, Division of Air Quality

Mountainland Association of Governments

Kathy McMullen, Director, Regional Planning Department

Parson, Behle, and Lattimer

Shelly Cordon Teuscher, Director of Government Relations

Sierra Club

Nina Dougherty, Volunteer; Associate Director for Research, Spencer S. Eccles Health

Sciences Library, University of Utah

Federal Highway Administration

Robin Smith, Air Quality-Urban Transportation Planner

U.S. Environmental Protection Agency

Jeff Houk, Environmental Engineer, Air Program, Region 8

SAN FRANCISCO

Metropolitan Transportation Commission

Chris Brittle, Planning Manager

William Hein, Deputy Executive Director

David Tannehill, Senior Planner
Appendix III: Interview Subjects by Study Site 138

Alameda County

Edward Campbell, Supervisor, First District

Contra Costa Transportation Authority

Bob McCleary, Executive Director

San Francisco Transportation Authority

Brigid Hynes-Cherin, Executive Director

California Department of Transportation

J. Steven Borroum, Chief, Environmental Engineering, Office of Environmental 

Engineering

California State Senate Transportation Committee

Mehdi Morshed, Staff Director

California Air Resources Board

Anne Geraghty, Manager, Transportation Strategies Group

Tess Sicat, Office of Air Quality and Transportation Planning

Doug Thompson, Associate Transportation Planner, Executive Office, Transportation

Strategies

Bay Area Air Quality Management District

David Marshall, Supervising Environmental Planner

Jean Roggenkamp, Manager, Planning and Transportation Section

International Institute for Surface Transportation Policy Studies

Rod Diridon, Executive Director

Regional Alliance for Transit

Matt Williams, Investment Adviser

John Woodbury

Sierra Club Legal Defense Fund

William S. Curtiss, Managing Attorney, San Francisco Regional Office

Sierra Club

John Holtzclaw

Federal Highway Administration

Karen Schmidt, Environmental Specialist, California Division

Robert O’Loughlin, Air Quality Specialist

U.S. Environmental Protection Agency

Mark Brucker, Environmental Scientist, Mobile Sources Section, Region 9
Appendix III: Interview Subjects by Study Site 139

NATIONAL

Federal Highway Administration, U.S. Department of Transportation

Lucy Garliauskas, Division of Environmental Analysis

Michael Savonis, Division of Environmental Analysis

James Shrouds, Chief, Division of Environmental Analysis

Environmental Protection Agency

Margo Oge, Director, Office of Mobile Sources

Meg Patulski, Office of Mobile Sources

Kathryn Sargent, Office of Mobile Sources

Laura Voss, Office of Mobile Sources

Environmental Defense Fund

Michael Replogle, Co-Director, Transportation Project

Robert Yuhnke, Attorney

Surface Transportation Policy Project

Hank Dittmar, Executive Director
LINKING TRANSPORTATION AND AIR QUALITY PLANNING:

IMPLEMENTATION OF THE 

TRANSPORTATION CONFORMITY REGULATIONS 

IN 15 NONATTAINMENT AREAS

Arnold M. Howitt and Elizabeth M. Moore

Taubman Center for State and Local Government

John F. Kennedy School of Government

Harvard University

March 1999

A Report to the

U.S. Environmental Protection Agency

and the

Federal Highway Administration,

U.S. Department of Transportation

Publication Number

EPA420-R-99-011

APPENDIX IV: SOURCES OF POPULATION 

AND TRANSPORTATION DATA
Appendix IV

SOURCES OF POPULATION AND TRANSPORTATION DATA

Atlanta

Population Source: U.S. Census Bureau, Total Resident Population from 1996 USA County General

Profile of all counties in the ozone nonattainment area. Accessed from http://www.census.gov/

datamap/www/13.html on December 17, 1998. 

VMT Source: Atlanta Regional Commission, personal correspondence with Chris Chovan. 

Baltimore

Population Source: U.S. Census Bureau, Total Resident Population from 1996 USA County General

Profile of all counties within ozone nonattainment area. Accessed from http://www.census.gov/

datamap/www/24.html on December 17, 1998.

VMT Source: Maryland State Highway Administration, “A Baltimore Region Daily Vehicle Miles

of Travel (In Millions of Miles by Jurisdiction for All Systems)” as supplied by Matthew M. De

Rouville of Baltimore Metropolitan Council.

Boston

Population Source: U.S. Census Bureau, Total Resident Population from 1996 USA County General

Profile of all counties in the ozone nonattainment area. Accessed from http://www.census.gov/

datamap/www/25.html on December 17, 1998.

VMT Source: Boston MPO, personal correspondence with Ann McGahan, staff member of Central

Transportation Planning Staff.

Charlotte

Population Source: U.S. Census Bureau, Total Resident Population from 1996 USA County General

Profile of all counties in the ozone nonattainment area. Accessed from http://www.census.gov/

datamap/www/37.html on December 17, 1998.

VMT Source: City of Charlotte, personal correspondence with Joseph McLelland, transportation

planner.

Chicago

Population Source: U.S. Census Bureau, Total Resident Population from 1996 USA County General

Profile of all counties in the ozone nonattainment area. Accessed from http://www.census.gov/

datapmap/www/17.html on December, 17, 1998.

VMT Source: Chicago Area Transportation Study, personal correspondence with Eugene Ryan,

Associate Executive Director.
Appendix IV: Sources of Population and Transportation Data 141

Denver

Population Source: U.S. Census Bureau, Total Resident Population from 1996 USA County General

Profile of all counties in the ozone nonattainment area. Accessed from http://www.census.gov/

datamap/www/18.html on December 17, 1998.

VMT Source: Denver Regional Council of Governments, personal correspondence with Christopher

Primus.

Houston

Population Source: U.S. Census Bureau, Total Resident Population from 1996 USA County General

Profile of all counties in the ozone nonattainment area. Accessed from http://www.census.gov/

datamap/www/48.html on December 17, 1998.

VMT Source: Houston-Galveston Area Council, Personal correspondence with Jacquie Lentz, chief

air quality planner.

Milwaukee

Population Source: U.S. Census Bureau, Total Resident Population from 1996 USA County General

Profile of all counties in the ozone nonattainment area. Accessed from http://www.census.gov/

datamap/www/55.html on December 17, 1998. 

VMT Source: Southeastern Wisconsin Regional Planning Commission, personal correspondence with

Ken Yunker, Assistant Director.

New York City

Population Source: U.S. Census Bureau, Total Resident Population from 1996 USA County General

Profile of all counties in the ozone nonattainment area. Accessed from http://www.census.gov/

datamap/www/36.html on December17, 1998.

VMT Source: New York Metropolitan Transportation Council, Personal correspondence with Mary

Vogel, staff member.

Northern New Jersey

Population Source: U.S. Census Bureau, Total Resident Population from 1996 USA County General

Profile of all counties in the ozone nonattainment area. Accessed from http://www.census.gov/

datamap/www/34.html on December17, 1998.

VMT Source: North Jersey Transportation Planning Authority, Personal correspondence with Julia

Zhou, manager of regional and sub-regional modeling.
Appendix IV: Sources of Population and Transportation Data 142

Philadelphia

Population Source: U.S. Census Bureau, Total Resident Population from 1996 USA County General

Profile of all counties in the ozone nonattainment area. Accessed from http://www.census.gov/

datamap/www/42.html on December 17, 1998.

VMT Source: Delaware Valley Regional Planning Commission, personal correspondence with Ronald Roggenburk.

Phoenix

Population source: U.S. Census Bureau, Total Resident Population from 1996 USA County General

Profile of all counties in ozone nonattainment area. Accessed from http://www.census.gov/

datamap/www/04.html on December 17, 1998.

VMT Source: Maricopa Association of Governments, personal correspondence with Cathy Arthur.

Portland

Population Source: U.S. Census Bureau, Total Resident Population from 1996 USA County General

Profile of all counties in ozone nonattainment area. Accessed from http://www.census.gov/

datamap/www/41.html on December 17, 1998. 

VMT Source: METRO Transportation Department, personal correspondence with Terry Whisler,

senior transportation planner.

Salt Lake City

Population Source: U.S. Census Bureau, Total Resident Population from 1996 USA County General

Profile of all counties in ozone nonattainment area. Accessed from http://www.census.gov/

datamap/www/49.html on December 17, 1998.

VMT Source: Wasatch Front Regional Council, personal correspondence with Kip Billings,

transportation engineer.

San Francisco

Population Source: U.S. Census Bureau, Total Resident Population from 1996 USA County General

Profile of all counties in ozone nonattainment area. Accessed from http://www.census.gov/

datamap/www/06.html on December 17, 1998.

VMT Source: Metropolitan Transportation Commission, “San Francisco Bay Area, County &

Regional Vehicles Miles of Travel, Population and Employment: 1990-1995.” Accessed from

http://www.mtc.ca.gov/facts_and_figures/misc/VMT9095.html on July 13, 1998.
LINKING TRANSPORTATION AND AIR QUALITY PLANNING:

IMPLEMENTATION OF THE 

TRANSPORTATION CONFORMITY REGULATIONS 

IN 15 NONATTAINMENT AREAS

Arnold M. Howitt and Elizabeth M. Moore

Taubman Center for State and Local Government

John F. Kennedy School of Government

Harvard University

March 1999

A Report to the

U.S. Environmental Protection Agency

and the

Federal Highway Administration,

U.S. Department of Transportation

Publication Number

EPA420-R-99-011

APPENDIX V: REPORT AUTHORS
Appendix V

REPORT AUTHORS

ARNOLD M. HOWITT is Executive Director of the Taubman Center for State and Local

Government at the John F. Kennedy School of Government, Harvard University. He also serves as

Executive Director of the Cooperative Mobility Program, an international transportation research

program based at the Massachusetts Institute of Technology.

Dr. Howitt’s research focuses on transportation, environmental regulation, and urban physical

development issues. In addition to his work on air quality and transportation in the United States, partially

reflected in this report, he is studying similar issues internationally, particularly in Japan. Dr. Howitt is the

author of Managing Federalism (CQ Press), a study of the federal grant-in-aid system, and co-author and

co-editor of Perspectives on Management Capacity Building (SUNY Press). He is a contributor to

Essays in Transport Economics and Policy (Brookings, 1999).

Dr. Howitt earned a B.A. degree from Columbia University and M.A. and Ph.D. degrees in

political science from Harvard University. He has served in faculty and administrative positions at

Harvard since 1976.

ELIZABETH M.MOORE is currently a transportation planner with Vanasse Hangen Brustlin,

Inc., in Watertown, Massachusetts, where she specializes in planning and implementation of transportation demand management strategies. Previously, as a Research Coordinator at the Taubman

Center for State and Local Government, Kennedy School of Government, she participated in

transportation and air quality studies. Prior to working at the Kennedy School, she directed a Transportation Management Association in Cambridge, MA.

Ms. Moore earned both a B.S. and M.S. degree from Colorado State University in the 1970s and

a Master in City Planning degree from the Massachusetts Institute of Technology in 1994.