Mobile Sources (General & Transportation Conformity)

Contact: Breanna Bukowski, 517-284-6737
Agency: Environmental Quality

Mobile engines burn fuel and generate air pollution through combustion or evaporation that impacts the air we breathe. Key pollutants produced include: carbon monoxide, hydrocarbons, nitrogen oxides, particulate matter, air toxics (including diesel exhaust), and greenhouse gases. The U.S. government is responsible for regulating mobile sources. The DEQ Air Quality Division (AQD) encourages public awareness and promotes emission reductions through clean air choices.

Transportation Planning

Under the 1990 Clean Air Act Amendments, the U.S. Department of Transportation cannot fund, authorize, or approve federal actions to support programs or projects which are not first found to conform to the Clean Air Act requirements. Transportation conformity applies to transportation plans, transportation improvement programs, and projects funded or approved by Federal Highway Administration (FHWA) or Federal Transit Administration (FTA) in areas that do not meet National Ambient Air Quality Standards (NAAQS) (non-attainment areas) or have not met them in the past (maintenance areas). It ensures that federal funding and approval are awarded only to projects that attain the NAAQS for ozone, carbon monoxide, particulate matter, and nitrogen dioxide. The FHWA and the FTA jointly make transportation conformity determinations.

The Congestion Mitigation and Air Quality Improvement (CMAQ) Program is jointly administered by the FHWA and FTA. It provides funding to state and local agencies, and to transportation planning organizations, to invest in projects that both contribute to air quality improvements and congestion relief. CMAQ is funded by the Moving Ahead for Progress in the 21st Century Act (MAP-21) signed into law in July 2012. The AQD is part of a collaborative effort along with MDOT, the USEPA, and the FHWA.

General Conformity

General conformity applies to all federal actions including funding, licensing, permitting, and approval (except for FHWA/FTA projects defined in 40 CFR 93.101) in areas deemed non-attainment or maintenance for any of the NAAQS criteria pollutants (ozone, carbon monoxide, particulate matter, nitrogen dioxide, lead, and sulfur dioxide). For example, general conformity applies to the majority of airport activities (construction, additions) funded by federal monies. Like transportation conformity, general conformity ensures that actions slated for completion will not cause additional, worsen existing, or contribute to new violations of the NAAQS or lead to a delay in reaching attainment.

Mobile Sources / Fuels

Other Resources