Guidance for Developing Transportation 

Conformity State Implementation Plans 

(SIPs) 
Guidance for Developing Transportation 


Conformity State Implementation Plans 


(SIPs) 


Transportation and Regional Programs Division 

Office of Transportation and Air Quality 

U.S. Environmental Protection Agency 

EPA-420-B-09-001 

January 2009 
TABLE OF CONTENTS 

Section 1: Introduction................................................................................................................. 1 

1.1 What is the purpose of this guidance document?.....................................................................................1 

1.2 What is transportation conformity? .........................................................................................................1 

1.3 In what part of the regulations is the requirement for conformity SIPs found? ......................................2 

1.4 What is a conformity SIP and how does it differ from other types of SIPs?...........................................2 

1.5 What agencies are typically involved in the development of a conformity SIP? ....................................2 

1.6 How is this guidance document organized?.............................................................................................2 

1.7 Who can I contact and where can I find more information about conformity SIPs?...............................3 

1.8 Does this guidance create new requirements? .........................................................................................3 

Section 2: General Requirements for Developing a Conformity SIP....................................... 4 

2.1 What must a conformity SIP contain? .....................................................................................................4 

2.2 Can states include other conformity provisions in their conformity SIP on a voluntary basis?..............4 

2.3 When are conformity SIPs due? ..............................................................................................................5 

2.4 Does the Clean Air Act, as amended by SAFETEA-LU, create any new conformity SIP 

deadlines to submit a conformity SIP? ..........................................................................................................5 

2.5 How should states proceed if a conformity SIP was never submitted to EPA in the past? .....................5 

2.6 How should states proceed if a conformity SIP was submitted in the past that was never 

approved?.......................................................................................................................................................5 

2.7 How should states update previously approved conformity SIPs?..........................................................6 

2.8 What are the format options for adopting a conformity SIP and what are the requirements of 

each? ..............................................................................................................................................................6 

Section 3: Applicability of Federal Regulations and Conformity SIPs in Conformity 

Determinations .............................................................................................................................. 8

3.1 What criteria and procedures apply for conformity determinations in the absence of an 

approved state conformity SIP? .....................................................................................................................8 

3.2 What criteria and procedures apply for conformity determinations when a state has an 

approved conformity SIP? .............................................................................................................................8 

3.3 What criteria and procedures apply for conformity determinations when there are changes in 

statutes and court decisions?..........................................................................................................................9 

3.4 How can I find out what conformity criteria and procedures apply in my area?.....................................9 

Section 4: Specific Requirements for Developing a Conformity SIP.................................... 11 

4.1 How should a state include the three required provisions in a conformity SIP?...................................11 

4.2 Can a conformity SIP be prepared by repeating section 93.105 of the federal rule verbatim or 

by incorporating this section of the conformity rule by reference? .............................................................11 

4.3 How should a state include more provisions in their conformity SIP from 40 CFR part 93 if 

desired? ........................................................................................................................................................12 

4.4 If a state has prepared its conformity SIP by incorporating the conformity rule into the 

conformity SIP by reference rather than repeating the rule verbatim, do the changes made to the 

federal rule automatically apply in that state, or does the state still have to update the conformity 

SIP to take advantage of changes to the federal rule? .................................................................................12 

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4.5 Can a conformity SIP include provisions that are more stringent than the federal conformity 

rule?..............................................................................................................................................................12 

4.6 How should conformity SIPs address any agency, such as an MPO, that covers portions of 

more than one state?.....................................................................................................................................12 

4.7 If a state has a conformity SIP that refers to general types of agencies (e.g., MPOs) rather 

than specific agencies (e.g., an MPO for a specific area), do the provisions of the conformity SIP 

apply for new or expanded nonattainment areas?........................................................................................13 

4.8 When in the process does EPA, FHWA, or FTA sign an MOU or MOA? ...........................................13 

4.9 If a state wants to revise its MOU/MOA, must it be done through the SIP process, or can the 

state and other agencies revise the MOU/MOA through the interagency consultation process?................13 

4.10 How does a state develop a new conformity SIP or revise an existing conformity SIP, 

whether done via an MOU/MOA or state rule?...........................................................................................13 

APPENDICES ............................................................................................................................. 15

Appendix A: Checklist for Developing a Conformity SIP ..........................................................................15 

Appendix B: Conformity Model Rule ........................................................................................................20 

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Section 1: Introduction 

1.1 What is the purpose of this guidance document? 

This document provides guidance on the statutory and regulatory requirements for states to 

develop conformity state implementation plans (conformity SIPs). A conformity SIP includes a 

state’s specific criteria and procedures for certain aspects of the transportation conformity 

process. Where EPA has approved a state’s conformity SIP, the approved conformity SIP 

governs conformity determinations instead of the federal transportation conformity regulations 

(or conformity rule), for those aspects of the rule that it addresses and that are applicable. 

Clean Air Act section 176(c) is the statutory authority for transportation conformity (42 U.S.C. 

7506(c)). This section of the Clean Air Act was amended by provisions contained in the Safe, 

Accountable, Flexible, Efficient Transportation Equity Act: A Legacy for Users (SAFETEALU), which was signed into law on August 10, 2005 (Public Law 109-59). Among the changes 

Congress made to this section of the Clean Air Act was to streamline the requirements for state 

conformity SIPs. Subsequently, EPA published a final rule on January 24, 2008 to update the 

requirements for conformity SIPs as well as the other Clean Air Act provisions amended by 

Congress (73 FR 4420). 

This guidance document describes the new requirements for conformity SIPs, so that state and 

local agencies can prepare an approvable conformity SIP. This guidance document also covers 

what requirements apply for conformity determinations that occur before and after conformity 

SIPs are approved. 

This guidance supersedes EPA’s November 2004 conformity SIP guidance1 and the portion of 

the February 2006 interim SAFETEA-LU guidance2 related to conformity SIPs. 

1.2 What is transportation conformity? 

Transportation conformity ensures that federally supported transportation activities are consistent 

with (“conform to”) the purpose of the SIP. Transportation activities include transportation 

plans, transportation improvement programs (TIPs), and federally funded or approved highway 

or transit projects. Conformity to the purpose of the SIP means that transportation activities will 

not cause new air quality violations, worsen existing violations, or delay timely attainment of the 

relevant national ambient air quality standards (NAAQS or “standards”). 

Transportation conformity applies under EPA’s conformity regulations3 in nonattainment and 

maintenance areas for the following transportation-related criteria pollutants: ozone, particulate 

matter (PM2.5 and PM10), carbon monoxide (CO), and nitrogen dioxide (NO2). 

1

 Conformity SIP Guidance, EPA420-B-04-017, November 2004. 2

 Interim Guidance for Implementing the Transportation Conformity Provisions in the Safe, Accountable, Flexible, 

Efficient Transportation Equity Act: A Legacy for Users (SAFETEA-LU), EPA420-B-06-901, February 2006. 3

 40 CFR Part 51, Subpart T and Part 93, Subpart A

1
 EPA develops the conformity regulations in coordination with the Federal Highway 

Administration (FHWA) and Federal Transit Administration (FTA). 

1.3 In what part of the regulations is the requirement for conformity SIPs found? 

The regulations that explain the requirements for a conformity SIP are found at 40 CFR 51.390. 

This portion of the conformity regulation was updated in a final rule published on January 24, 

2008 (73 FR 4420). 

1.4 What is a conformity SIP and how does it differ from other types of SIPs? 

A conformity SIP is required to contain only the state’s criteria and procedures for interagency 

consultation (40 CFR 93.105) and two additional conformity provisions (40 CFR 93.122(a)(4)(ii) 

and 93.125(c)). Unlike a reasonable further progress SIP, an attainment demonstration, or 

maintenance plan, a conformity SIP does not contain motor vehicle emissions budgets, emissions 

inventories, air quality demonstrations, or control measures. A conformity SIP can be developed 

as a state rule, a memorandum of understanding (MOU), or a memorandum of agreement 

(MOA). Additional information is provided in Section 4 for developing or revising a 

MOU/MOA or a state rule. In general, once approved, the conformity SIP governs the 

conformity process instead of the federal conformity rule for any provisions included in the 

conformity SIP. 

1.5 What agencies are typically involved in the development of a conformity SIP? 

A formal interagency consultation process is used to prepare a conformity SIP. The consultation 

process includes representatives from state and local transportation and air quality agencies, 

EPA, FHWA, and FTA. Typically, the state air agency is the lead on conformity SIP 

development; although in limited cases MPOs or local air agencies play this role. 

1.6 How is this guidance document organized? 

The remaining parts of this guidance cover: 

• Section 2: General Requirements for Developing a Conformity SIP: This section 

provides general information regarding what is required to be included in a conformity 

SIP and when conformity SIPs are due. 

• Section 3: Applicability of Federal Regulations and Conformity SIPs in Conformity 

Determinations: This section outlines what requirements apply for conformity 

determinations that occur before and after a conformity SIP is approved. 

• Section 4: Specific Requirements For Developing a Conformity SIP Submission: This 

section provides specific details for developing and submitting a new or revised 

conformity SIP. 

• Appendices: This section provides a checklist to assist in preparing and reviewing a 

conformity SIP and model conformity SIP language. The Checklist (Appendix A) and 

Model Rule (Appendix B) are available for downloading at 

http://www.epa.gov/otaq/stateresources/transconf/policy.htm#sips 

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1.7 Who can I contact and where can I find more information about conformity SIPs? 

For specific questions concerning a particular conformity SIP, please contact the SIP or 

transportation conformity staff person responsible for your state at the appropriate EPA Regional 

Office. A listing of EPA Regional Offices, the states they cover, and contact information for 

EPA regional conformity staff can be found on EPA’s website at the following address: 

www.epa.gov/otaq/stateresources/transconf/contacts.htm. 

General questions about this guidance can be directed to: 

Astrid Larsen at EPA’s Office of Transportation and Air Quality, 

larsen.astrid@epa.gov or 734-214-4812. 

Additional information regarding the transportation conformity rule and associated guidance can 

be found on EPA’s website at: www.epa.gov/otaq/stateresources/transconf/index.htm. 

1.8 Does this guidance create new requirements? 

No, this guidance is based on Clean Air Act transportation conformity requirements, as amended 

by SAFETEA-LU, and existing associated regulations and does not create any new requirements. 

This guidance merely explains how to implement the new Clean Air Act conformity SIP-related 

provisions. 

The statutory provisions and the resulting EPA regulations described in this document contain 

legally binding requirements. This document is not a substitute for those provisions or 

regulations, nor is it a regulation itself. Thus, it does not impose legally binding requirements on 

EPA, DOT, states, or the regulated community, and may not apply to a particular situation based 

upon the circumstances. EPA retains the discretion to adopt approaches on a case-by-case basis 

that may differ from this guidance, but still comply with the statute and conformity regulations. 

Any decisions regarding a particular conformity SIP will be made based on the statute and 

regulations, after appropriate public input and rulemaking procedures, where applicable. This 

guidance may be revised periodically without public notice. 

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Section 2: General Requirements for Developing a Conformity SIP 

2.1 What must a conformity SIP contain? 

Clean Air Act section 176(c)(4)(E), as amended by SAFETEA-LU (August 2005), significantly 

streamlined the requirements for state conformity SIPs. Prior to SAFETEA-LU’s amendments 

to the Clean Air Act, states were required to address all of the federal transportation conformity 

regulations provisions in their conformity SIPs. Most of the sections of the federal rule were 

previously required to be copied verbatim from the federal rule into a state’s conformity SIP. 

Clean Air Act section 176(c)(4)(E) and section 51.390(b) of the conformity rule now require 

states to submit conformity SIPs that address only the following provisions of the federal 

conformity rule: 

• 40 CFR 93.105, which addresses consultation procedures; 

• 40 CFR 93.122(a)(4)(ii), which states that conformity SIPs must require that written 

commitments to control measures be obtained prior to a conformity determination if the 

control measures are not included in a metropolitan planning organization’s (MPO’s) 

transportation plan and TIP, and that such commitments be fulfilled; and 

• 40 CFR 93.125(c), which states that conformity SIPs must require that written 

commitments to mitigation measures be obtained prior to a project-level conformity 

determination, and that project sponsors comply with such commitments. 

These provisions must be tailored to a state’s individual circumstances, rather than including the 

federal conformity rule section verbatim. Section 4 and Appendix B contain additional 

information and examples of language that can be used to develop a state’s conformity SIP. 

2.2 Can states include other conformity provisions in their conformity SIP on a voluntary 

basis? 

Yes, the current Clean Air Act and the conformity rule allow states to include additional 

provisions beyond the three mentioned in Question 2.1. Section 51.390(b) provides that, “A 

state may elect to include any other provisions of part 93, subpart A.” However, as discussed in 

the January 24, 2008 final rule, EPA strongly encourages states to only include the three required 

provisions in a conformity SIP to take advantage of the streamlining flexibilities provided by the 

Clean Air Act, as amended by SAFETEA-LU. The new requirements will reduce the 

administrative burden for state and local agencies significantly, because the new requirements 

will minimize the possibility of having to revise the conformity SIP each time the federal rule is 

revised (73 FR 4430-4432). 

Any interested state and local agencies should consult with their EPA Regional Office to discuss 

the process and potential impacts of developing a conformity SIP that includes more than the 

required provisions. Additional details for developing such a SIP are included in Section 4 of 

this guidance document. 

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2.3 When are conformity SIPs due? 

Section 51.390(c) of the conformity rule explains when states are required to submit a new or 

revised conformity SIP. A conformity SIP must be submitted: 

• by November 25, 1994 or within 12 months of an area’s nonattainment designation if the 

state has not previously submitted one; 

• within 12 months of the publication date of any final amendments to 40 CFR 93.105, 

93.122(a)(4)(ii), and 93.125(c); 

• within 12 months of the publication date of any other final conformity amendments if a 

state’s conformity SIP includes the provisions of such final amendments. 

EPA discussed conformity SIP deadlines in the preamble to its January 2008 final rule (73 FR 

4432). 

Once a state has an approved conformity SIP that addresses only the three required sections, the 

state would need to revise its conformity SIP only if EPA substantively changes one of these 

three sections of the conformity rule, or the state chooses to revise one of these three provisions. 

Any future changes to the federal conformity rules that do not affect these three provisions 

would apply immediately in any state that has only the three provisions in its approved 

conformity SIP, and such changes would not need to be adopted into the state’s SIP to be 

applicable. 

2.4 Does the Clean Air Act, as amended by SAFETEA-LU, create any new conformity 

SIP deadlines to submit a conformity SIP? 

No, these amendments to the Clean Air Act did not create any new deadlines for conformity 

SIPs. See Question 2.3 for further information regarding when conformity SIPs must be 

submitted to EPA. 

2.5 How should states proceed if a conformity SIP was never submitted to EPA in the 

past? 

States that have never submitted a conformity SIP are required to address only the three 

provisions noted above in Question 2.1. 

2.6 How should states proceed if a conformity SIP was submitted in the past that was 

never approved? 

In some cases, states have submitted conformity SIPs to EPA for approval, but EPA has not yet 

acted on them. Such a situation can occur when a state submits a conformity SIP that becomes 

outdated prior to EPA approval. For example, a state’s conformity SIP can become outdated 

when a new rulemaking is promulgated or a court decision is issued and the conformity SIP does 

not reflect the latest revised requirements. EPA can only approve a conformity SIP provision 

that addresses the requirements of the Clean Air Act and EPA’s transportation conformity 

regulations that are in place at the time of EPA’s approval. 

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In cases where a state has submitted a conformity SIP to EPA that EPA has not approved, states 

can send a letter to their EPA Regional Office and request that EPA approve only the three 

provisions that are required to be included in their SIPs, and that EPA take no action on the 

remainder of the submitted conformity SIP. Alternatively, the state could send a letter to its EPA 

Regional Office requesting to withdraw the entire submission (73 FR 4431, January 24, 2008). 

The state would then submit a new conformity SIP consistent with the current Clean Air Act and 

transportation conformity regulations. 

States should work closely with their EPA Regional Office when requesting action on or 

withdrawing a previous conformity SIP submission. 

2.7 How should states update previously approved conformity SIPs? 

States with EPA-approved conformity SIPs that decide to eliminate the provisions that are no 

longer mandatory would need to revise the SIP to eliminate those provisions (73 FR 4431, 

January 24, 2008). EPA will consider using either parallel processing (when requested by the 

state) or direct final approval to expedite the approval of such conformity SIP revisions. Such a 

conformity SIP revision should not be controversial because the provisions are no longer 

required by the current Clean Air Act. In addition, their elimination from a state’s conformity 

SIP should not change conformity’s implementation in practice, because the federal conformity 

rule applies for any provision not addressed in a state’s conformity SIP. 

States may also need to revise an approved conformity SIP that includes provisions that are now 

outdated (e.g., if EPA promulgated a final rule that substantively revised the federal conformity 

rule provisions on which a conformity SIP is based). 

States are encouraged to work with their EPA Regional Office as early in the process as possible 

to ensure the conformity SIP submission meets all requirements and is fully approvable. 

2.8 What are the format options for adopting a conformity SIP and what are the 

requirements of each? 

A conformity SIP can be adopted as a state rule, as a memorandum of understanding (MOU), or 

memorandum of agreement (MOA). See Section 4 for additional information for developing or 

revising conformity SIPs, either as an MOA/MOU or state rule. The appropriate form of the 

state conformity procedures depends upon the requirements of local or state law, as long as the 

selected form complies with all Clean Air Act requirements for adoption, submission to EPA, 

and implementation of SIPs. EPA will accept state conformity SIPs in any form provided the 

state can demonstrate to EPA’s satisfaction that, as a matter of state law, the state has adequate 

authority to compel compliance with the requirements of the conformity SIP (58 FR 62209-

62209, November 24, 1993). 

A state can use an MOU or MOA for its conformity SIP if such a memorandum meets the 

following requirements: 

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1. it is fully enforceable under state law against all parties involved in interagency 

consultation and in approving, adopting and implementing transportation plans, TIPs, or 

transportation projects; 

2. the state submits it to EPA for inclusion into the SIP; and, 

3. it has been signed by all agencies that are covered by the conformity rule, including 

federal agencies and the recipients of funds designated under title 23 U.S.C. or the 

Federal Transit Laws (see the definition in 40 CFR 93.101). For example, MOU/MOA 

signers would include MPOs, local and state air agencies, state DOTs, transit agencies, 

FHWA, FTA, and EPA, and all current recipients of title 23 U.S.C. or the Federal Transit 

Laws funds (as defined under 40 CFR 93.101). 

If the conformity SIP is in the form of a state rule, then any new agencies not previously covered 

by the conformity rule are automatically covered by the rule. This could happen if an area that 

has never been subject to conformity before were to become a newly designated nonattainment 

area. In such a case, there would be agencies in that area that are new to the interagency 

consultation process. 

For a conformity SIP in the form of an MOU/MOA, the MOU must provide that the signatories 

will require new federal funding recipients to sign the MOU/MOA. 

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Section 3: Applicability of Federal Regulations and Conformity SIPs in Conformity 

Determinations 

This section outlines the general applicability of conformity criteria and procedures in areas with 

and without approved conformity SIPs. Questions 3.1 and 3.2 cover the general requirements, 

while Question 3.3 covers the exception to these general requirements. 

3.1 What criteria and procedures apply for conformity determinations in the absence of 

an approved state conformity SIP? 

States without an approved conformity SIP must meet Clean Air Act section 176(c) requirements 

when performing transportation plan, TIP and project-level conformity determinations. 

Transportation conformity determinations must meet the conformity rule provisions found in 40 

CFR 51.390(a), which states: 

The federal conformity rules under part 93, subpart A, of this chapter, in addition to any 

existing applicable state requirements, establish the conformity criteria and procedures 

necessary to meet the requirements of the Clean Air Act section 176(c) until such time as EPA 

approves the conformity implementation plan revision required by this subpart....The federal 

conformity regulations contained in part 93, subpart A, of this chapter would continue to apply 

for the portion of the requirements that the state did not include in its conformity 

implementation plan and the portion, if any, of the state’s conformity provisions that is not 

approved by EPA. 

For example, areas without any approved conformity SIP provisions are required to follow all of 

the relevant provisions of the conformity rule. Similarly, in states with approved conformity 

SIPs that address only the three provisions now required, (i.e., §§93.105, 93.122(a)(4)(ii), and 

93.125(c)), conformity must be determined according to all of the relevant provisions of the 

conformity rule, and the requirements for consultation and written commitments governed by the 

state’s conformity SIP. 

Please see Question 3.2 for more information regarding areas with approved conformity SIPs. 

There can also be exceptions to this general case where neither the federal conformity rule nor an 

approved conformity SIP provisions apply; see Question 3.3 below for further information. 

3.2 What criteria and procedures apply for conformity determinations when a state has an 

approved conformity SIP? 

Conformity determinations must meet any provisions in an EPA-approved conformity SIP that 

are consistent with section 176(c) of the Clean Air Act, even if the conformity SIP provisions are 

different than those in the conformity rule. Section 40 CFR 51.390(a) states that, “any 

previously applicable implementation plan conformity requirements remain enforceable until the 

state submits a revision to its applicable implementation plan to specifically remove them and 

that revision is approved by EPA.” Therefore, states whose conformity SIPs address provisions 

that are still consistent with the statute but that have subsequently been updated in the conformity 

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rule cannot take advantage of EPA’s updated regulations unless and until the state revises its 

conformity SIP and EPA approves it. 

For example, some areas may have approved conformity SIPs that include outdated versions of 

the PM10 hot-spot requirements. If an approved conformity SIP includes the PM10 hot-spot 

provisions prior to those promulgated in the March 10, 2006 final rule, then all project-level 

conformity determinations must include a PM10 hot-spot analysis (71 FR 12468). In contrast, the 

federal conformity rule now requires only some project-level conformity determinations in PM10 

areas to include hot-spot analyses (40 CFR 93.123(b)). 

This example illustrates the advantages to updating any previously approved conformity SIPs, to 

ensure that conformity rule changes apply upon EPA’s promulgation. The interagency 

consultation process should be used to determine what requirements apply for conformity 

determinations in states with approved conformity SIPs. 

Please note there are cases where neither the conformity rule nor approved conformity SIP 

provisions apply. See Question 3.3 for further information. 

3.3 What criteria and procedures apply for conformity determinations when there are 

changes in statutes and court decisions? 

Conformity determinations must be consistent with section 176(c) of the Clean Air Act. There 

have been cases where certain provisions of the federal conformity rule and approved conformity 

SIP provisions have become outdated, either because Congress amended the Clean Air Act or a 

federal court issued a decision that vacated a federal conformity rule provision. In such cases, 

the affected federal conformity rule provision(s) or the affected approved state conformity SIP 

provision(s) no longer apply. When these cases occur, conformity determinations must meet any 

new or revised requirements, which are usually described by interim federal guidance issued 

prior to a conformity rule revision. Once EPA updates the conformity rule to reflect such 

changes, the revised conformity rule applies immediately upon its effective date. 

For example, when the Clean Air Act was amended by SAFETEA-LU in August 2005, the 

required frequency for transportation plan and TIP conformity determinations was changed from 

every three years to every four years. Therefore, the provisions in the conformity rule and in any 

approved conformity SIPs that required conformity of transportation plans and TIPs every three 

years no longer applied. EPA and DOT issued interim guidance4

 to ensure that conformity 

determinations would be consistent with the statutory changes prior to EPA’s January 2008 final 

rule (73 FR 4420). The revised four-year frequency of conformity determinations for 

transportation plans and TIPs applied in all nonattainment and maintenance areas upon 

SAFETEA-LU’s enactment in August 2005, even in areas with approved conformity SIPs that 

included outdated provisions. In this case, a conformity SIP revision is not required prior to the 

application of the new frequency requirement. 

3.4 How can I find out what conformity criteria and procedures apply in my area? 

4

 Interim Guidance for Implementing the Transportation Conformity Provisions in the Safe, Accountable, Flexible, 

Efficient Transportation Equity Act: A Legacy for Users (SAFETEA-LU), EPA420-B-06-901, February 2006. 

9
To find out if an approved conformity SIP already applies in your area, please contact the 

transportation conformity staff person at the appropriate EPA Regional Office. A list of these 

regional transportation conformity staff and their contact information can be found at the 

following website: Regional Contacts | State & Local Transportation Resources | US EPA. 

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Section 4: Specific Requirements for Developing a Conformity SIP 

As described in Question 2.1, section 51.390(b) of the conformity rule requires states to submit 

conformity SIPs that address the following provisions of the conformity rule: 

• 40 CFR 93.105, which addresses consultation procedures; 

• 40 CFR 93.122(a)(4)(ii), which states that conformity SIPs must require that written 

commitments to control measures be obtained prior to a conformity determination if the 

control measures are not included in an MPO’s transportation plan and TIP, and that such 

commitments be fulfilled; and 

• 40 CFR 93.125(c), which states that conformity SIPs must require that written 

commitments to mitigation measures be obtained prior to a project-level conformity 

determination, and that project sponsors comply with such commitments. 

This section covers how to address these specific requirements within a conformity SIP 

submission. Appendix A includes a checklist for developing a conformity SIP and Appendix B 

contains a model conformity rule. 

4.1 How should a state include the three required provisions in a conformity SIP? 

To assist states with developing a conformity SIP, EPA has provided suggested language, in the 

form of a Model Rule, to meet the requirements of 40 CFR 93.105, 93.122(a)(4)(ii), and 

93.125(c) in Appendix B. While the Appendix is presented in the order of the conformity rule, 

states are not bound by this order and are free to rearrange the requirements to best suit their 

needs. 

Consultation procedures that fulfill 40 CFR 93.105 will make up the majority of a state’s 

conformity SIP. Once approved by EPA, the conformity SIP will guide a nonattainment or 

maintenance area’s future consultation for conformity determinations. Because of the 

importance of the consultation process and the number of conformity rule provisions required by 

40 CFR 93.105, the state should carefully prepare this portion of the conformity SIP to ensure 

that all the requirements are covered and organized in a logical fashion. 

4.2 Can a conformity SIP be prepared by repeating section 93.105 of the federal rule 

verbatim or by incorporating this section of the conformity rule by reference? 

No, a conformity SIP that repeats 40 CFR 93.105 verbatim or incorporates this provision by 

reference would not meet statutory and regulatory requirements. Section 93.105 only describes 

what must be included in the conformity SIP and does not contain specific criteria and 

procedures that states would need to adopt to meet the consultation requirements, as required by 

the Clean Air Act. In addition, such a conformity SIP would not be practical, since creating a 

specific interagency consultation process is one of the primary purposes of developing a 

conformity SIP. 

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4.3 How should a state include more provisions in their conformity SIP from 40 CFR part 

93 if desired? 

States may include additional transportation conformity provisions in their conformity SIP on a 

voluntary basis, as described in Question 2.2. If they do so, the provisions must be adopted 

verbatim. This requirement is found in the conformity rule at 40 CFR 51.390(b), “A state may 

elect to include any other provisions of part 93, subpart A....such provisions must be included in 

verbatim form, except insofar as needed to clarify or give effect to a stated intent...” 

4.4 If a state has prepared its conformity SIP by incorporating the conformity rule into the 

conformity SIP by reference rather than repeating the rule verbatim, do the changes made to the 

federal rule automatically apply in that state, or does the state still have to update the conformity 

SIP to take advantage of changes to the federal rule? 

The answer depends on what the conformity SIP indicates: 

• If a state incorporates the conformity rule into its conformity SIP by reference, it may 

have incorporated the conformity rule that existed as of the date of the incorporation. If 

so, subsequent updates to the conformity rule do not automatically apply and a revision to 

the conformity SIP must be submitted within 12 months of the effective date of a change 

to the conformity rule. 

• However, a conformity SIP that incorporates the conformity rule by reference could 

also indicate that it also incorporates by reference any future changes made to the 

conformity, although this is rare. In this case, the conformity SIP does not need to be 

revised when the conformity rule is updated. 

If your state has an approved conformity SIP that incorporates the conformity rule by reference, 

and you are unsure about whether the conformity SIP includes the latest conformity rule 

provisions, please consult with your EPA Regional Office (see Question 1.7 for contact 

information). 

4.5 Can a conformity SIP include provisions that are more stringent than the federal 

conformity rule? 

Yes, states can include criteria and procedures in their conformity SIPs that are more stringent 

than the conformity rule as long as they apply equally to federal and non-federal entities, 

pursuant to 40 CFR 51.390(b) (see also 58 FR 62209). 

4.6 How should conformity SIPs address any agency, such as an MPO, that covers 

portions of more than one state? 

Special consultation provisions need to be included in a conformity SIP when it covers an MPO 

whose jurisdiction covers parts of more than one state. In these cases, it is important that MPOs 

can follow similar conformity procedures in the different states, since each conformity SIP 

applies only within each own state. For example, in multi-state nonattainment and maintenance 

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areas where the states work together to make conformity determinations, it is necessary for 

consultation procedures to be substantially similar in each state’s portion of the area. In these 

cases, EPA recommends that the interagency consultation process be used to develop similar 

consultation procedures that each state would then include in its own conformity SIP. Such 

states may also want to consider additional provisions for dealing with interstate conflicts (40 

CFR 93.105(d)), to ensure that an appropriate process is in place if necessary. 

4.7 If a state has a conformity SIP that refers to general types of agencies (e.g., MPOs) 

rather than specific agencies (e.g., an MPO for a specific area), do the provisions of the 

conformity SIP apply for new or expanded nonattainment areas? 

The answer depends on the wording of the conformity SIP itself. If the SIP’s wording could be 

interpreted to include expanded or new nonattainment areas in the state, the provisions of the 

conformity SIP would apply to these areas. However, if the conformity SIP includes wording 

that limits its applicability to particular areas, then it may not apply to new or expanded areas. If 

your state has an approved conformity SIP and you are unsure whether it applies to your 

particular area, please consult with your EPA Regional Office (see Question 1.7 for contact 

information). 

4.8 When in the process does EPA, FHWA, or FTA sign an MOU or MOA? 

The EPA Regional Administrator, FHWA, and FTA would sign an MOU/MOA before it is 

endorsed by the governor and submitted to EPA as part of the SIP. EPA, FHWA, and FTA 

cannot sign the MOU after it is submitted to EPA because these agencies cannot amend a 

submitted SIP. 

4.9 If a state wants to revise its MOU/MOA, must it be done through the SIP process, or 

can the state and other agencies revise the MOU/MOA through the interagency consultation 

process? 

An MOU/MOA revision would have to be approved through the SIP process because the 

MOU/MOA is part of the SIP. 

4.10 How does a state develop a new conformity SIP or revise an existing conformity 

SIP, whether done via an MOU/MOA or state rule? 

To develop a new conformity SIP or revise an existing conformity SIP, either as a state rule or 

MOU/MOA, the process is generally the same for either format (state rule or MOU/MOA): 

Step 1: The conformity SIP is developed or revised through consultation of the interagency 

workgroup at the state and/or local level. 

Step 2: The state holds a public comment period on the document. 

Step 3: The document is submitted to EPA as a SIP revision. 

13
Step 4: Once at the EPA, the submission would then continue through the usual SIP process 

for approval/disapproval. 

The difference between a state rule versus an MOU/MOA is that after the revision is prepared, a 

conformity SIP developed as a state rule has to go through a state’s regulatory process and be 

adopted. In contrast, a conformity SIP revision prepared as an MOU/MOA requires signatures 

from all the relevant parties before it is submitted to EPA. 

Before a state decides to use the MOU/MOA format, the state must determine if the state has the 

legal authority to use this method, as described in Question 2.8. 

14
APPENDICES

The Checklist for Developing a Conformity SIP (Appendix A) and Conformity Model Rule 

(Appendix B) are available for downloading at 

http://www.epa.gov/otaq/stateresources/transconf/policy.htm#sips 

Appendix A: Checklist for Developing a Conformity SIP 

This checklist is intended to guide state and local agencies as they develop their conformity SIPs; 

this checklist does not replace existing statutory or regulatory requirements. Within each section 

of the checklist, the requirements are shown in the left-hand column. The right-hand column can 

be used to record the locations in the consultation and conformity SIP that address the required 

elements. 

INTERAGENCY CONSULTATION 

GENERAL: [93.105(a)]. A conformity SIP shall include procedures for interagency consultation, conflict 

resolution, and public consultation. EPA encourages development of Aextensive, effective consultation 

procedures that will resolve problems as early in the process as possible.@ 58 FR 62188 at 62201, 

November 24, 1993. The procedures must be written in a manner that gives them full legal effect. 40 

CFR 51.390. 

Consultation is required on the development of the regional 

transportation plan (RTP), the transportation improvement 

program (TIP), on conformity determinations, and on the 

development of state implementation plan (SIP) revisions that 

affect transportation. [93.105(a)(1)]. 

MPOs and State departments of transportation must provide 

reasonable opportunity for consultation with State air agencies, 

local air quality and transportation agencies, DOT, and EPA, 

including consultation on specific processes for interagency 

consultation. [93.105(a)(2)] 

INTERAGENCY CONSULTATION PROCEDURES: GENERAL FACTORS [93.105(b)]. States shall provide 

well defined consultation procedures in the implementation plan. Organizations with responsibilities for 

developing, submitting or implementing provisions of an implementation plan (including MPOs, State 

and local air quality planning agencies, and State and local transportation agencies) must consult with 

each other with and local or regional offices of EPA, the Federal Highway Administration (FHWA), and 

the Federal Transit Administration (FTA). 

The interagency consultation procedures must include, at a minimum, the following general factors: 

procedures that require that agencies consult on the 

development of the implementation plan, the transportation 

plan, the TIP, and associated conformity determinations 

[93.105(b)(1)]; 

15
the roles and responsibilities of each agency at each stage in the 

SIP development process and the transportation planning 

process, including technical meetings [93.105(b)(2)(i)]; 

the organizational level of regular consultation5 

[93.105(b)(2)(ii)]; 

a process for circulating (or providing ready access to) draft 

documents and supporting materials for comment before formal 

adoption or publication [93.105(b)(2)(iii)]; 

the frequency of, or process for convening, consultation 

meetings and responsibility for establishing meeting agendas 

[93.105(b)(2)(iv)]; 

a process for responding to significant comments of involved 

agencies [93.105(b)(2)(v)]; and 

a process for the development of a list of the transportation 

control measures (TCMs) that are in the applicable 

implementation plan [93.105(b)(2)(vi)]. 

SPECIFIC PROCESSES Interagency consultation procedures shall include the specific processes listed 

below [93.105(c)]: 

A process involving at least the MPO(s), State and local air quality planning and transportation agencies, 

EPA, and the Department of Transportation (DOT) for the following [93.105(c)(1)]: 

Evaluating and choosing models and associated methods and 

assumptions for hot-spot and regional emissions analyses 

[93.105(c)(1)(i)]; 

Determining which minor arterials and other projects are 

“regionally significant”6 for the regional emissions analysis (in 

addition to those functionally classified as principal arterials or 

higher or fixed guide way systems or extensions that offer an 

alternative to regional highway travel) [93.105(c)(1)(ii)]; 

Determining which projects should be considered to have a 

significant change in design concept and scope from the RTP or 

TIP [93.105(c)(1)(ii)]; 

Evaluating whether otherwise exempt projects (see 93.126 and 

93.127) should be treated as non-exempt where adverse 

impacts are possible for any reason [93.105(c)(1)(iii)]; 

Determining whether past obstacles to implementation of 

transportation control measures (TCMs) in approved SIPs have 

been identified and are being overcome (for TCMs behind SIP 

schedules) [93.105(c)(1)(iv); 93.113(c)(1)]; 

5 Generally, interagency consultation procedures should include information such as the organizational 

level and procedures for the people who schedule, lead, and attend meetings. 

6

 This is in addition to the projects required to be included by application of the definition of Aregionally 

significant project@ in 40 CFR 93.101. 

16 
Determining whether State and local agencies are giving 

maximum priority to approval and funding for TCMs in 

approved SIPs [93.105(c)(1)(iv)]; 

Determining whether delays in the implementation of approved 

SIP TCMs necessitate revisions to the SIP to remove or 

substitute such TCMs or other emission reduction measures 

[93.105(c)(1)(iv)]; 

Notification of transportation plan and TIP amendments which 

only add or delete exempt projects listed in 93.126 and 93.127 

[93.105(c)(1)(v)]; and 

Choosing conformity tests and methodologies for isolated rural 

nonattainment and maintenance areas, as required by 

93.109(l)(2)(iii) [93.105(c)(1)(vi)]. 

A process involving at least the MPO and State and local air and transportation agencies for 

[93.105(c)(2)]: 

Evaluating events that will trigger new conformity 

determinations in addition to those required by 93.104 

[93.105(c)(2)(i)]; and 

Consulting on emissions analysis for transportation activities 

which cross borders of MPOs, nonattainment areas or air basins 

[93.105(c)(2)(ii)]. 

Where the metropolitan planning area does not include the entire 

nonattainment or maintenance area, procedures must specify a 

process involving the MPO and the State DOT for cooperative 

planning and analysis for determining conformity of projects outside 

the metropolitan area and within the nonattainment or maintenance 

area [93.105(c)(3)]. 

Specifies a process to ensure disclosure of plans for regionally 

significant non-FHWA/FTA projects (including projects for which 

alternatives are still being considered) to the MPO on a regular basis, 

and immediate disclosure of any changes to those plans 

[93.105(c)(4)]. 

Provides a process involving the MPO and other federal funds 

recipients for assuming project location and design concept/scope 

where these features not adequately defined for regional emissions 

analysis [93.105(c)(5)]. 

Specifies a process for consulting on design, schedule, and funding 

of research and data collection efforts and regional transportation 

model development by the MPO [93.105(c)(6)]. 

Specifies a process for providing final documents and supporting 

information to each agency (including federal agencies) after 

approval or adoption [93.105(c)(7)]. 

RESOLVING CONFLICTS [93.105(d)]. 

The process for resolving conflicts must specify that: 

Unresolvable conflicts among state agencies or between state 

17
agencies and an MPO shall be escalated to the Governor or 

Governor=s designee (designee can not be the State or local air 

agency, State department of transportation, State transportation 

commission or board, or an MPO) [93.105(d)]; 

The State air agency has 14 calendar days (the implementation 

plan should define the procedures for starting the 14-day clock) 

to appeal to the Governor after the State DOT or MPO has 

notified the State air agency head of the resolution of his or her 

comments [93.105(d)]; and 

If the State air agency appeals to the Governor, the final 

conformity determination must have Governor=s concurrence. 

If there is no appeal, the MPO or state DOT may proceed with 

the final conformity determination [93.105(d)]. 

PUBLIC CONSULTATION PROCEDURES. Affected agencies7 making conformity determinations on 

transportation plans, TIPs, and projects shall establish a proactive public involvement process [93.105(e)]. 

This general requirement can be satisfied by referencing the MPO’s procedures,8 in addition to specifying 

or referencing the additional items listed below. 

Consultation procedures must set out a public process that, at a minimum: 

Provides for reasonable public access to technical and policy 

information considered by the agency at the beginning of the 

public comment period and prior to taking formal action on a 

transportation plan or TIP conformity determination, consistent 

with 93.105 and 23 CFR 450.316(a) [93.105(e)]; 

Ensures that any charges imposed for public inspection or 

copying are reasonable [49 CFR 7.43, 93.105(e)]; 

Provides that agencies must specifically address in writing all 

public comments that plans for regionally significant 

non-FHWA/FTA projects are not properly reflected in the 

emissions analysis [93.105(e)]; and 

Provides opportunity for public involvement in project 

conformity determinations as otherwise required by law 

[93.105(e)]. 

7

 Interagency consultation portions of transportation conformity SIPs should define the “affected agencies” 

that are responsible for fulfilling 40 CFR 93.105(e) requirements. 8

 The specific requirements and criteria for MPO public involvement are set forth at 23 CFR 450.316(a). 

Under these requirements, MPOs are directed to periodically review their public involvement process to assure that 

full and open access is provided to MPO decision-making processes (see 23 CFR 450.316(a)(1)(x)). Public 

involvement provisions are reviewed in the context of certification or planning reviews, which are conducted by 

FHWA and FTA under 23 CFR 450.334(b) no less often than once every four years for certain MPOs. 

18 
OTHER CONFORMITY PROCEDURES: Under Clean Air Act, as amended by SAFETEA-LU, conformity 

SIPs must also include conformity procedures that address 40 CFR 93.122(a)(4)(ii) and 93.125(c). All 

other federal conformity regulations apply automatically and states are not required to address them in 

conformity SIPs. 

ENFORCEABLE WRITTEN COMMITMENTS REQUIRED FOR EMISSIONS REDUCTION CREDIT: Emissions 

reduction credit from any control measures that are not included in the transportation plan and TIP and 

that do not require a regulatory action in order to be implemented may not be included in the emissions 

analysis unless the conformity determination includes written commitments to implementation from the 

appropriate entities [93.122(a)(4)(ii)]. 

Language addressing 93.122(a)(4)(ii) should include, at a minimum, the following: 

In accordance with 40 CFR 93.122(a)(4)(ii), prior to making a 

conformity determination on the Transportation Plan or TIP, [insert 

MPO name] will not include emissions reduction credits from any 

control measures that are not included in the Transportation Plan or 

TIP and that do not require a regulatory action in the regional 

emissions analysis used in the conformity analysis unless [insert 

MPO name] or FHWA/FTA obtains written commitments, as defined 

in 40 CFR 93.101, from the appropriate entities to implement those 

control measures. The written commitments to implement those 

control measures must be fulfilled by the appropriate entities 

[93.122(a)(4)(ii)]. 

ENFORCEABILITY OF DESIGN CONCEPT AND SCOPE AND PROJECT-LEVEL MITIGATION AND CONTROL 

MEASURES: Before a conformity determination is made, written commitments must be obtained for any 

project-level mitigation or control measures. [93.125(c)] 

Language addressing 93.125(c) should include, at a minimum, the following: 

In accordance with 40 CFR 93.125(c), prior to making a project-level 

conformity determination for a transportation project, FHWA/FTA 

must obtain from the project sponsor and/or operator written 

commitments, as defined in 40 CFR 93.101, to implement any 

project-level mitigation or control measures in the construction or 

operation of the project identified as conditions for NEPA process 

completion. The written commitments to implement those projectlevel mitigation or control measures must be fulfilled by the 

appropriate entities. Prior to making a conformity determination on 

the Transportation Plan or TIP, [insert MPO name] will ensure any 

project-level mitigation or control measures are included in the 

project design concept and scope and are appropriately identified in 

the regional emissions analysis used in the conformity analysis. Prior 

to making a project-level conformity determination, written 

commitments will be obtained before such mitigation or control 

measures are used in a project-level hot-spot conformity analysis. 

19
Appendix B: Conformity Model Rule9 

CONFORMITY TO STATE IMPLEMENTATION PLANS (SIPs) OF 

TRANSPORTATION PLANS, PROGRAMS, AND PROJECTS DEVELOPED, FUNDED OR 

APPROVED UNDER TITLE 23 U.S.C. OR THE FEDERAL TRANSIT LAWS 

I. Introduction 

The purpose of this state rule is to fulfill the requirement in 40 CFR 51.390(b) to establish a SIP 

revision that includes the following three sections of the federal transportation conformity rule: 

• 40 CFR 93.105, which addresses consultation procedures; 

• 40 CFR 93.122(a)(4)(ii), which states that conformity SIPs must require that written 

commitments to control measures be obtained prior to a conformity determination if the 

control measures are not included in a metropolitan planning organization’s (MPO’s) 

transportation plan and transportation improvement program (TIP); and that such a 

commitment be fulfilled; and 

• 40 CFR 93.125(c), which states that conformity SIPs must require that written 

commitments to mitigation measures be obtained prior to a project-level conformity 

determination, and that project sponsors comply with such commitments. 

Once this state rule is approved by EPA into the [name of state] implementation plan, it has full 

legal effect. Conformity determinations will be governed by these criteria and procedures as 

well as any applicable portions of the federal conformity rules that are not addressed by the state 

rule. 

II. Consultation

 (a) General. 

This rule provides procedures for federal, state, and local interagency consultation, public 

consultation and resolution of conflicts. Such consultation procedures shall be undertaken by 

MPOs, the State department of transportation, other local transportation agencies, and DOT with 

State and local air quality agencies and EPA before making conformity determinations, and by 

State and local air agencies and EPA with MPOs, the State department of transportation, and 

DOT in developing applicable implementation plans. 

(b) Interagency consultation procedures: General factors. 

(1)(A) Representatives of the MPOs, State and local air quality planning agencies, State and 

local transportation agencies, and [specify any other organizations within the State with 

responsibilities for developing, submitting, or implementing provisions of an implementation 

9 This model rule was adapted from Transportation and General Conformity Under the Clean Air, Model Rules for 

State and Local Agencies, STAPPA-ALAPCO, June 1994. EPA was consulted in the development of this 

document. 

20
plan required by the CAA] shall undertake an interagency consultation process in accordance 

with this section with each other and with local or regional offices of EPA, FHWA, and FTA on 

the development of the SIP, the transportation plan, and the TIP, and associated conformity 

determinations. 

(B) The State air quality agency [specify name, unless another entity has responsibility for 

submitting SIPs] shall be the lead agency responsible for preparing the final document or 

decision and for assuring the adequacy of the interagency consultation process with respect to the 

development of SIPs and the list of TCMs in the approved SIP. The MPO [specify name or 

names, where possible] shall be the lead agency responsible for preparing the final document or 

decision and for assuring the adequacy of the interagency consultation process with respect to the 

transportation plan, the TIP, any amendments or revisions thereto, and any conformity 

determinations. In the case of non-metropolitan areas, the State department of transportation 

[specify name] shall be the lead agency responsible for preparing the final document or decision 

and for assuring the adequacy of the interagency consultation process with respect to the 

development of any conformity determinations in these areas. 

(C) In addition to the lead agencies identified in subparagraph (B), other agencies entitled to 

participate in any interagency consultation process under this rule include the State department 

of transportation [specify name], each affected MPO [specify name or names for each affected 

area], the Federal Highway Administration field office [specify name], the Federal Transit 

Administration regional office [specify name], any county congestion management agencies 

[specify name], the State air quality agency [specify name], any air quality management district, 

air pollution control district or other local air quality agency [specify name or names for each 

affected area], any other organization within the State responsible under State law for 

developing, submitting or implementing transportation-related provisions of an implementation 

plan [specify name, if any], and any local transportation agency or local government as 

appropriate [specify name or names for each affected area]. 

(D) It shall be the role and responsibility of each lead agency in an interagency consultation 

process, as specified in subparagraph (B), to confer with all other agencies identified under 

subparagraph (C) with an interest in the document to be developed, provide all appropriate 

information to those agencies needed for meaningful input, solicit early and continuing input 

from those agencies, conduct the consultation process described in the applicable paragraphs of 

40 CFR 93.105, where required, assure policy-level contact with those agencies and prior to 

taking any action, consider the views of each such agency and respond to those views in a 

timely, substantive written manner prior to any final decision on such document, and assure that 

such views and written response are made part of the record of any decision or action. It shall 

be the role and responsibility of each agency specified in subparagraph (C), when not fulfilling 

the role and responsibilities of a lead agency, to confer with the lead agency and other 

participants in the consultation process, review and comment as appropriate (including 

comments in writing) on all proposed and final documents and decisions in a timely manner, 

attend consultation and decision meetings, assure policy-level contact with other participants, 

provide input on any area of substantive expertise or responsibility (including planning 

assumptions, modeling, information on status of TCM implementation, and interpretation of 

regulatory or other requirements), and provide technical assistance to the lead agency or 

consultation process in accordance with this paragraph when requested. 

21
[To address the requirements of 93.105(b)(2)(i) and (ii)] 

(E) Specific roles, responsibilities, and organizational level of various participants in the 

interagency consultation process shall be as follows [Note: This is a partial, illustrative list 

only. Current responsibilities and needed assignments should be taken into account.]: 

(i) The State air quality agency [or local air quality agency, if appropriate under State law; 

specify name; these functions may have to be allocated between State and local agencies to 

reflect State law] shall be responsible for developing (I) emissions inventories, (II) emissions 

budgets, (III) air quality modeling, (IV) SIP demonstrations, including emissions budgets as 

necessary, (V) any SIP TCMs, and (VI) ...; 

(ii) The MPO [specify name] shall be responsible for (I) developing transportation plans and 

TIPs, (II) evaluating TCM transportation impacts, (III) developing transportation and 

socioeconomic data and planning assumptions for use in emissions analysis to determine 

conformity of transportation plans, TIPs, and projects, (IV) monitoring regionally significant 

projects, (V) developing system- or facility-based or other programmatic TCMs, (VI) providing 

technical and policy input on emissions budgets, (VII) performing transportation modeling, 

regional emissions analyses and documentation of timely implementation of TCMs needed for 

conformity assessments, and (VIII) ...; 

(iii) The State department of transportation [specify name] shall be responsible for (I) providing 

technical input on proposed revisions to motor vehicle emissions factors, (II) distributing draft 

and final project environmental documents to other agencies, (III) convening air quality technical 

review meetings on specific projects when requested by other agencies or as needed, and (IV) ...; 

(iv) FHWA and FTA shall be responsible for (I) assuring timely action on final findings of 

conformity, after consultation with other agencies as provided in this section, (II) providing 

guidance on the transportation planning process to agencies in interagency consultation, and 

(III) ...; and 

(v) EPA shall be responsible for (I) reviewing, finding adequate, and approving updated motor 

vehicle emissions budgets, (II) providing guidance on conformity criteria and procedures to 

agencies in interagency consultation, and (III).... 

[NOTE: The model rule in paragraph (2) below expresses general principles of consultation. 

It is not intended to be adopted in this form, but should be adapted to the circumstances of the 

State, the usual relationships of parties to the negotiation, and other factors. A State may wish 

to adopt more than one consultation procedure, with differing complexity, to apply to different 

documents or decisions, as appropriate for the subject matter. An approvable conformity 

implementation plan revision will need to incorporate more detail on consultation than 

provided by this model rule. Among the terms that may require further definition by the State 

are "early in the process,” “timely,” “period for review,” “policy level,” “ the record of any 

decision or action,” “ all relevant documents,” “ all appropriate information,” “consider” and 

“respond." Where "final document" is referred to, this shall also include any decisions or 

actions not requiring a specific document.] 

22
[To address the requirements of 40 CFR 93.105(b)(2)(iii), (iv), (v), and (vi)] 

(2)(A) It shall be the affirmative responsibility of the agency with the responsibility for 

preparing the final document or decision subject to the interagency consultation process to 

initiate the process by notifying other participants, convene consultation meetings early in the 

process of decision on the final document, appoint the convenors of technical meetings, and 

assure that all relevant documents and information are supplied to all participants in the 

consultation process in a timely manner. 

(B) Regular consultation on major activities such as the development of a SIP, the development 

of a transportation plan, the development of a TIP, or any determination of conformity on 

transportation plans or TIPs, shall include meetings at regular, scheduled intervals no less 

frequently than [insert frequency - monthly/quarterly/ semiannually to determine appropriate 

interval for the agencies and subject matter involved] and shall be attended by representatives of 

each agency. In addition, technical meetings shall be convened as necessary. 

(C) Each lead agency in the consultation process required under this section (that is, the agency 

with the responsibility for preparing the final document subject to the interagency consultation 

process) shall confer with all other agencies identified under paragraph (1) with an interest in the 

document to be developed, provide all appropriate information to those agencies needed for 

meaningful input, and, prior to taking any action, consider the views of each such agency and 

respond to those views in a timely, substantive written manner prior to any final decision on such 

document. Such views and written response shall be made part of the record of any decision or 

action. 

(D) The lead agency for developing the SIP will prepare a list of the TCMs in the approved SIP 

and provide this list to the interagency consultation process in accordance with paragraph (b). 

[To address the requirements of 93.105(c)] 

(c) Interagency consultation procedures: Specific processes. 

(1) An interagency consultation process in accordance with paragraph (b) involving the MPO, 

State and local air quality planning agencies, State and local transportation agencies, EPA, 

FHWA, and FTA shall be undertaken for the following: 

(i) Evaluating and choosing a model (or models) and associated methods and assumptions to be 

used in hot-spot analyses and regional emissions analyses to be initiated by [identify lead 

agency] and conducted in accordance with paragraph (b). 

(ii) Determining which minor arterials and other transportation projects should be considered 

"regionally significant" for the purposes of regional emissions analysis (in addition to those 

functionally classified as principal arterial or higher or fixed guideway systems or extensions that 

offer an alternative to regional highway travel), and which projects should be considered to have 

a significant change in design concept and scope from the transportation plan or TIP, to be 

initiated by [identify lead agency] and conducted in accordance with paragraph (b); 

(iii) Evaluating whether projects otherwise exempted from meeting the requirements of 40 CFR 

Part 93 (i.e. projects described in 40 CFR 93.126 and 93.127) should be treated as non-exempt in 

23
cases where potential adverse emissions impacts may exist for any reason, to be initiated by 

[identify lead agency] and conducted in accordance with paragraph (b); 

(iv) Making a determination, as required by 40 CFR 93.113(c)(1), whether past obstacles to 

implementation of TCMs which are behind the schedule established in the applicable 

implementation plan have been identified and are being overcome, and whether State and local 

agencies with influence over approvals or funding for TCMs are giving maximum priority to 

approval or funding for TCMs, to be initiated by [identify lead agency] and conducted in 

accordance with paragraph (b). This consultation process shall also consider whether delays in 

TCM implementation necessitate revisions to the applicable implementation plan to remove 

TCMs or substitute TCMs or other emission reduction measures; 

(v) Notification of transportation plan or TIP revisions or amendments which merely add or 

delete exempt projects listed in 40 CFR 93.126, to be initiated by [identify lead agency] and 

conducted in accordance with paragraph (b); 

(vi) Choosing conformity tests and methodologies for isolated rural nonattainment and 

maintenance areas, as required by 40 CFR 93.109(1)(2)(iii) to be initiated by [identify lead 

agency] and conducted in accordance with paragraph (b). 

(2) An interagency consultation process in accordance with paragraph (b) involving the MPO, 

State and local air quality planning agencies, and State and local transportation agencies, shall be 

undertaken for the following: 

(i) Evaluating events which will trigger new conformity determinations in addition to those 

triggering events established in 40 CFR 93.104, to be initiated by [identify lead agency] and 

conducted in accordance with paragraph (b); and 

(ii) Consulting on emissions analysis for transportation activities which cross the borders of 

MPOs or nonattainment areas or air basins, to be initiated by [identify lead agency] and 

conducted in accordance with paragraph (b). 

(3) Where the metropolitan planning area does not include the entire nonattainment or 

maintenance area, an interagency consultation process involving the MPO and the State 

department of transportation shall be undertaken for cooperative planning and analysis for 

purposes of determining conformity of all projects outside the metropolitan area and within the 

nonattainment or maintenance area, to be initiated by [identify lead agency] and conducted in 

accordance with paragraph (b). 

(4)(i) An interagency consultation process in accordance with paragraph (b) involving the MPO, 

State and local air quality planning agencies, State and local transportation agencies, and 

recipients of funds designated under title 23 U.S.C. or the Federal Transit Act shall be 

undertaken to assure that plans for construction of regionally significant projects which are not 

FHWA/FTA projects (including projects for which alternative locations, design concept and 

scope, or the no-build option are still being considered), including all those by recipients of funds 

designated under title 23 U.S.C. or the Federal Transit Act are disclosed to the MPO on a regular 

basis, and to assure that any changes to those plans are immediately disclosed. 

24
(ii) During preparation of the transportation plan and TIP, the MPO will request that participants 

of the interagency consultation process identify all non-FHWA/FTA transportation projects and 

their design concept and scope, including those where detailed design features have not yet been 

decided, and determine which ones meet the definition of regionally significant for regional 

emissions modeling. Any recipient of federal funding, as defined in 40 CFR 93.101, is required 

to disclose to the MPO information regarding all non-FHWA/FTA regionally significant projects 

and any changes to these plans shall be immediately disclosed. 

(5) An interagency consultation process in accordance with paragraph (b) involving the MPO 

and other recipients of funds designated under title 23 U.S.C. or the Federal Transit Act shall be 

undertaken for assuming the location and design concept and scope of projects that are disclosed 

to the MPO as required by paragraph (c)(4) of this section but whose sponsors have not yet 

decided these features, in sufficient detail to perform the regional emissions analysis according to 

the requirements of 40 CFR 93.122, to be initiated by [identify lead agency] and conducted in 

accordance with paragraph (b). 

(6) An interagency consultation process involving the MPO, State and local air quality planning 

agencies, and State and local transportation agencies, shall be undertaken for the design, 

schedule, and funding of research and data collection efforts and regional transportation model 

development by the MPO (e.g., household/ travel transportation surveys), to be initiated by 

[identify lead agency] and conducted in accordance with paragraph (b). 

(7) A process for providing final documents (including SIPs, transportation plans, TIPs, plan/TIP 

amendments and conformity determinations) and supporting information to each agency after 

approval or adoption. This process is applicable to all agencies including MPOs, State 

department of transportation, State and local air quality agencies, FHWA, FTA and EPA. 

(d) Resolving conflicts. 

(1) Any conflict among State agencies or between State agencies and an MPO shall be escalated 

to the Governor if the conflict cannot be resolved by the heads of the involved agencies. In the 

first instance, such agencies shall make every effort to resolve any differences, including 

personal meetings between the heads of such agencies or their policy-level representatives, to the 

extent possible. 

(2)(A) The State air quality agency has 14 calendar days to appeal a proposed determination of 

conformity (or other policy decision under this rule) to the Governor after the State DOT or 

MPO has notified the State air quality agency of the resolution of all comments on such proposed 

determination of conformity or policy decision. Such 14-day period shall commence when the 

MPO or the State DOT has confirmed receipt by the director of the State air agency of the 

resolution of the comments of the State air quality agency. If the State air quality agency appeals 

to the Governor, the final conformity determination must have the concurrence of the Governor. 

The State air quality agency must provide notice of any appeal under this subsection to the MPO 

and the State DOT. If the State air quality agency does not appeal to the Governor within 14 

days, the MPO or State DOT may proceed with the final conformity determination. 

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(B) In the case of any comments with regard to any proposed determination of conformity, the 

State DOT has 14 calendar days to appeal a proposed determination of conformity (or other 

policy decision under this rule) to the Governor after the MPO has notified the State air quality 

agency or the State DOT of the resolution of all comments on such proposed determination of 

conformity or policy decision. Such 14-day period shall commence when [insert defining action, 

e.g., the MPO has confirmed receipt by the director of the State air agency or the State DOT of 

the resolution of the comments of the State DOT]. If the State DOT appeals to the Governor, the 

final conformity determination must have the concurrence of the Governor. The State DOT must 

provide notice of any appeal under this subsection to the MPO and the State air quality agency. 

If the State DOT does not appeal to the Governor within 14 days, the MPO may proceed with the 

final conformity determination. 

(3) The Governor may delegate the role of hearing any such appeal under this subsection and of 

deciding whether to concur in the conformity determination to another official or agency within 

the State, but not to the head or staff of the State air quality agency or any local air quality 

agency, the State department of transportation, a State transportation commission or board, any 

agency that has responsibility for only one of these functions, or an MPO. 

(e) Public consultation procedures. 

The [list affected agencies] making conformity determinations on transportation plans, programs, 

and projects shall establish and make available a proactive public involvement process which 

provides opportunity for public review and comment. At a minimum, this process should 

include providing reasonable public access to technical and policy information considered by the 

agency at the beginning of the public comment period and prior to taking formal action on a 

conformity determination for all transportation plans and TIPs, consistent with those 

requirements and those of 23 CFR 450.316(a). 

Charges imposed for public inspection and copying are consistent with the fee schedule 

contained in 49 CFR 7.43. 

In addition, [list the agencies] will specifically address in writing all public comments that 

known plans for a regionally significant project which is not receiving FHWA or FTA funding or 

approval have not been properly reflected in the emissions analysis supporting a proposed 

conformity finding for a transportation plan or TIP. [List the agencies] will also provide 

opportunity for public involvement in conformity determinations for projects where otherwise 

required by law. 

III. Commitments for Regional Emissions Analysis 

In accordance with 40 CFR 93.122(a)(4)(ii), the [identify MPO] will not include emissions 

reduction credits from control measures that are not included in the transportation plan or 

transportation improvement program and that do not require a regulatory action in the regional 

emissions analysis used in the conformity determination unless [identify name of MPO] or 

FHWA/FTA obtain written commitments, as defined in 40 CFR 93.101, from the appropriate 

entities to implement those control measures. The written commitments to implement those 

control measures must be fulfilled by the appropriate entities. 

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IV. Commitments for Project-Level Mitigation and Control Measures 

In accordance with 40 CFR 93.125(c), prior to making a project-level conformity determination 

for a transportation project, FHWA/FTA must obtain from the project sponsor and/or operator a 

written commitment, as defined in 40 CFR 93.101, to implement any project-level mitigation or 

control measure in the construction or operation of the project identified as a condition for NEPA 

process completion. The written commitment to implement such a project-level mitigation or 

control measure must be fulfilled by the appropriate entity. Prior to making a conformity 

determination for the transportation plan or TIP, [identify name of MPO] will ensure any projectlevel mitigation or control measures for which a written commitment has been made are included 

in the project design concept and scope and are appropriately identified in the regional emissions 

analysis used in the conformity analysis. Written commitments must be obtained before such 

mitigation or control measures are used in a project-level hot-spot conformity analysis for a 

project-level determination. 

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