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Reference Material

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The following are reference materials developed by FHWA and others to help practitioners in the implementation of the transportation conformity process. Other resources also are available under the "Research" and "Tools and Methodologies" topics.

All Documents

• AASHTO Center on Environmental Excellence - Air Quality Community of Practice.
• Transportation and General Conformity Frequently Asked Questions (HTML) or (PDF - 33Kb)- FAQs regarding common questions and scenarios where the transportation and general conformity regulations may intersect for certain transportation projects and clarification on how the requirements can be met
• Areas Where Conformity Has Lapsed (July 2012) - Periodic update that lists areas of the country where conformity has lapsed
• Transportation Conformity Reference Guide (March 2006) - FHWA reference manual that contains the transportation conformity rule and relevant preamble language, questions and answers, and lists of resource materials
• PM2.5 Project-Level Conformity and Hot-Spot Analyses - FAQs about PM2.5 project-level conformity and hot-spot analyses
• Transportation Conformity and the New Air Quality Standards - FAQs about transportation conformity issues related to the July 1, 2004, amendments to include criteria and procedures for the 1997 8-hour ozone and 1997 PM2.5 NAAQS
• 2006 PM2.5 Nonattainment Area Maps - 2006 PM2.5 Nonattainment Area Maps - Individual maps of each nonattainment area for PM2.5 in the country.
• 1997 8-hour Ozone Nonattainment Area Maps - Individual maps of each nonattainment area for 8-hour ozone in the country
• 1997 Particulate Matter (PM2.5) Nonattainment Area Maps - Individual maps of each nonattainment area for PM2.5 in the country
• National Ambient Air Quality Standards (NAAQS) - Primary and secondary standards for the criteria pollutants
• Examples of Transportation Conformity Practices - Examples of approved PM hot-spot analyses, PM hot-spot procedures, CO protocols, and SIPs with on-road mobile source strategies
• EPA Green Book - Listing of those areas of the country that are currently designated nonattainment or maintenance
• Transportation Conformity Alert - August 2000 - Reminders pertaining to Peak and Off-Peak Speeds, PM Qualitative Analysis, Latest Planning Assumptions, Motor Vehicle Emissions Budgets in SIPs, TCMs in SIPs, and Partial Implementation of TCMs
• EPA's Adequacy Review of SIP Submissions for Conformity - Statement that conformity determinations cannot be based on submitted SIP emissions budgets, prior to a positive adequacy determination by EPA
• Air Quality Planning for Transportation Officials - Overview of air quality planning requirements of the Clean Air Act that are transportation-related

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