Air Quality Planning for Transportation Officials
Air quality planning, done by State and local air agencies, can have direct implications on transportation plans, programs, and projects. Transportation agencies should participate fully in the air quality planning process to ensure that decisions made reflect community priorities, including mobility. |
The purpose of this guide is to provide an overview of the air quality planning requirements of the Clean Air Act (CAA) that are transportation-related. Effective air quality planning and transportation planning must be firmly integrated. This guide is intended for transportation officials that are involved with transportation planning and program development. It aims to provide a basic understanding of the air quality planning requirements of the CAA, and how they affect transportation planning and transportation choices. This guide seeks to inform the transportation community about the opportunities and constraints created by the integration of air quality planning with transportation planning, so that we may collectively achieve both our air quality and transportation goals.
For further information on the topic, the National Highway Institute offers a course on the Implications of Air Quality Planning on Transportation.
In this guide:
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Air Quality Planning for Transportation Officials: An Introduction
- National Ambient Air Quality Standards
- Monitoring for Air Quality Levels
- Nonattainment Area Boundaries
- State Implementation Plans (SIPs)
- SIP Deadlines and Attainment Dates
- Mobile Source Emissions Inventory
- Control Strategy Development
- Transportation Control Measures
- Motor Vehicle Emissions Budget
- Sanctions
- Transportation Conformity
- Interagency Consultation and Public Involvement
- Conclusion
- Glossary
Air pollution comes from many different sources: stationary sources such as factories and power plants; smaller, dispersed sources (known as area sources) such as dry cleaners and painting operations; mobile sources such as cars, buses, planes, trucks, and trains; and naturally occurring sources such as windblown dust, and volcanic eruptions. Mobile sources can be further subdivided into on-road sources such as automobiles, trucks and buses, and non-road sources such as construction and farm equipment, airplanes, boats, and trains. The CAA provides the principal framework for National, State, and local efforts to protect air quality from all man-made pollution sources.
The CAA requires that, in areas experiencing air quality problems, transportation planning must be consistent with air quality goals. This is determined through the transportation conformity process. In some areas, this process has forced State and local transportation officials to make tough decisions in order to meet both air quality and mobility goals. Where CAA goals were not being met, some State and local transportation officials have been challenged to find ways to reduce vehicle emissions by developing transportation plans, TIPs, and projects that will alter travel patterns, reduce the number of single-occupant vehicles, and make alternative modes of transportation (such as transit and bicycles) an increasingly important part of the transportation network.
