Policy and Technical Guidance
EPA has developed many guidance documents for state, local, and tribal governments to use in state implementation plan (SIP) or other air quality planning documents to meet Clean Air Act (CAA) requirements. The CAA is the comprehensive federal law that regulates air emissions from mobile sources.
Background information and guidance are organized and can be accessed as follows.
- Background on CAA Mobile Source Programs for Ozone: CAA includes mobile source control requirements that depend upon an area's ozone nonattainment classification, such as vehicle inspection and maintenance (I/M) programs, reformulated gasoline, and VMT Offset demonstrations.
- Guidance on CAA Mobile Source Requirements: Other parts of the State and Local Transportation website contain guidance for implementing CAA requirements for mobile sources. Quick links include:
- General Guidance on Innovative and Voluntary Air Pollution Control Strategies: EPA has developed guidance for including voluntary and innovative emission reduction programs in SIPs, including economic incentive programs.
- Guidance on Control Strategies: EPA has developed several SIP guidance documents for quantifying and using emission reductions from specific control strategies, such as commuter programs and diesel retrofit and replacement projects.
- Guidance on Emissions Models and Developing SIP Emission Inventories: EPA’s MOtor Vehicle Emission Simulator (MOVES), AP-42, and CA’s EMFAC model are used in SIP inventory development. See EPA’s Transportation Conformity website for information on the latest available models for SIP development as well as inventory guidance.
- EPA's Port Emissions Inventory Guidance provides methodologies on how to develop port-related and goods movement emissions inventories. This guidance has specific information on how to develop inventories for criteria pollutants and precursors. This guidance also describes the latest, state-of-the-science methodologies for preparing an emissions inventory in the following mobile source sectors: ocean-going vessels, harbor craft, recreational marine, cargo handling equipment, onroad vehicles, and rail.