This guide was updated in February 2017.
Transportation Conformity: A Basic Guide for State and Local Officials
Responsibility for Making a Conformity Determination
The policy board of a Metropolitan Planning organization (MPO) must formally make a conformity determination on its metropolitan transportation plans and TIPs prior to submitting them to FHWA/FTA for an independent review and conformity determination. The conformity process is done in accordance with the required interagency consultation process described below. For individual projects including those in rural areas, the State department of Transportation (DOT) or project sponsor usually prepares the conformity analysis. FHWA or FTA must make a project-level conformity determination prior to project approval and/or funding. Exhibit 4 shows the typical roles and responsibilities of the various agencies.
Exhibit 4
Roles and Responsibilities of Federal, State, and Local Transportation and Air Quality Agencies in Transportation Conformity and SIP Development Process
(Specific States and metropolitan areas may have negotiated different assignments of responsibility tailored to local conditions.)
| Agencies |
Roles and Responsibilities |
When |
| MPO |
- Conduct analysis on metropolitan transportation plan/TIP
- Incorporate latest emissions factors, planning assumptions, and emissions models
- Circulate draft metropolitan transportation plan/TIP for interagency and public comment based on public involvement procedures adopted by the MPO
- Ensure public involvement procedures are followed
- Ensure timely implementation of TCMs
- Respond to significant comments on TIP/metropolitan transportation plan conformity documents
- Determine conformity on metropolitan transportation plan/TIP
- Consult with agencies throughout the conformity determination process
- Consult on the development of the SIP and motor vehicle emissions budgets
- May elect to shorten conformity horizon after consultation with air agency and public comment
- Participate in the TCM substitution process
- Concur on TCM substitutions
|
- At least every 4 years or when a metropolitan transportation plan/ TIP is updated or amended with non-exempt projects
- 24 months after certain SIP actions
- 12 months after new nonattainment designations become effective
- As needed
|
| State/Local Transportation Agency |
- Consult with agencies throughout the conformity determination process
- Conduct regional conformity analysis on projects not in metropolitan areas, based on interagency consultation
- In CO and PM nonattainment and maintenance areas, conduct "hot-spot" analysis, if necessary as part of a project-level conformity determination
- Provide for public involvement/respond to significant comments
- Ensure timely implementation of TCMs
- Review and approve staff regional and hot-spot analysis
- Consult on the development of the SIP and motor vehicle emissions budgets
- Participate in the TCM substitution process
- Concur on TCM substitutions in isolated rural areas
|
|
| State/Local Air Quality/Environmental Agency |
- Prepare SIP for each relevant pollutant
- Ensure interagency involvement during SIP development (including the State DOT and MPO(s))
- Hold public hearings prior to SIP adoption
- Ensure SIPs are complete and control measures are enforceable under the 1990 CAA, prior to board approval action
- Ensure latest emissions factors and planning assumptions are used for SIP development
- Review and approve SIP, forward to EPA for Federal approval
- Participate in the interagency consultation process for metropolitan transportation plan/TIP/project development and conformity determinations
- Consult on shortened conformity horizon
- Participate in the TCM substitution process and submit substitute TCM to EPA
- Concur on TCM substitutions
|
|
| State Legislature |
- Adopt State legislation to develop and enforce applicable CAA provisions
- Ensure funding available for implementation of programs and projects
|
|
| FHWA/FTA |
- Make conformity determinations on metropolitan transportation plans/TIPs updates/amendments and projects
- Participate in the interagency consultation process for metropolitan transportation plan/TIP development and conformity determinations
- Ensure timely implementation of TCMs
- Ensure MPOs allow for adequate public involvement
- Ensure that all other conformity and metropolitan transportation planning requirements are met
- Develop technical guidance on traffic demand and forecasting, and Federal aid program guidance
- Consult on the development of the SIP and motor vehicle emissions budgets
|
- At least every 4 years or when a metropolitan transportation plan/ TIP is updated or amended with non-exempt projects
- 24 months after certain SIP actions
- 12 months after new nonattainment designations become effective
- As needed
|
| EPA |
- Develop conformity rules, regulations, and guidance documents
- Consult on the development of the SIP and motor vehicle emissions budgets
- Review submitted budgets for adequacy and implement adequacy process
- Provide technical guidance on TCMs and SIP development
- Review and comment on draft and submitted control strategy and maintenance SIPs
- Review, comment, and approve SIPs
- Participate in the interagency consultation process for metropolitan transportation plan/TIP/project development and conformity determinations
- Review and comment on proposed conformity determinations
- Designate approved emissions models for use in SIP development and conformity determinations
- Designate "guideline" dispersion models for project-level emissions analysis
- Participate in the TCM substitution process and codify substitute TCM into SIPs
- Concur on TCM substitutions
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