The EMission FACtors (EMFAC) model is the primary tool for assessing emissions from on-road vehicles including cars, trucks, and buses in California.  EMFAC produces California's official on-road mobile source emission estimates which makes it an essential tool in developing regulations and control strategies to meet air quality requirements.  The EMFAC model is widely used in State Implementation Plan development, air quality planning and modeling, conformity assessments, and CEQA assessments for environmental impact reports.

The latest version of EMFAC, EMFAC2014, reflects ARB's latest understanding of vehicle usage, emissions levels and rule implementation assumptions.  ARB staff will provide an overview on the new model structure, major updates and primary applications.  A detailed discussion will be given on the project-level (PL) analysis functions, which provide emissions rates that can be used to quantify emissions on a project level for conformity or other environmental impact assessment purposes.