English French German Italian Portuguese Russian Spanish

Air Quality

Transportation Conformity (A Basic Guide for State & Local Officials) - 2017


2008 Ozone Standard Final Designation
The US Environmental Protection Agency (EPA) designated the Charlotte “Metrolina” region as a “marginal non-attainment” area for the 2008 ozone standard. A non-attainment area is an area designated by the EPA that does not meet the National Ambient Air Quality Standards (NAAQS).

On-road mobile sources, like cars, trucks, and buses found on our roadways, are a major source of ozone-forming pollution in the Charlotte Metrolina area.

What is Transportation Conformity?
Transportation conformity ensures that federal funding and approval are given to highway and transit projects that are consistent with ("conform to") the air quality goals established by a state air quality implementation plan (SIP): to meet the NAAQS. This process is required by the Clean Air Act (section 176(c) (42 U.S.C. 7506(c))).

The conformity process ensures planned transportation projects do NOT:

  1. Cause new violations of NAAQS;

  2. Increase frequency or severity of NAAQS violations; or

  3. Delay timely attainment of NAAQS or interim milestones.

The Clean Air Act requires CRTPO to demonstrate that its Transportation Improvement Program (TIP) and Metrolina Transportation Plan (MTP) conform to the SIP. Transportation conformity is an important part of CRTPO’s planning process.


Transportation Conformity Memorandum of Agreement
The Transportation Conformity Memorandum of Agreement (MOA) was prepared in response to a requirement of the Clean Air Act (section 176(c)(4)(E) to create a state conformity State Implementation Plan (SIP) containing three requirements of the Federal Transportation Conformity Rule, 40 CFR 93(A):


The MOA is designed to ensure that interagency consultation procedures for transportation conformity are followed in the region’s non-attainment area.