Mobile Source Emission Inventory

This page last updated on January 2013


Updated Release: January 2013 --> EMFAC2011

  • Includes a new handbook and tools with updated online databases and training that allow easier access to emission factor data and provide tips for project level assessment
  • Corrects the number of starts and associated emissions in Santa Clara County in EMFAC2011-LDV and EMFAC2011-SG, which had led to an overestimate of emissions. No other counties were affected and no model algorithms were changed in the update
  • Updates technical documentation to reflect these improvements
  • All EMFAC users should download the latest version of EMFAC2011-LDV and EMFAC2011-SG

Background

The mobile source emissions inventory is ARB’s tool for assessing the population, activity, and emissions from mobile sources.  These inventories are constantly being revised and updated to support the latest air quality plans and regulations.  Periodically these inventories are compiled and released to the public for use in transportation and air quality assessments both internal and external to the agency.  Mobile source inventories are developed by the Mobile Source Analysis Branch in the Planning and Technical Support Division.  In these web pages you will find two different ways of accessing current information.  Data can be accessed for specific regulatory items by mobile source category or through the methods and in some cases models that are used estimate emissions. 


Mobile Source Categories

Individual category-specific emissions estimates and documentation are developed for specific agency regulatory activities.  Categories include cars/light truck assessments for emissions standard development, heavy duty truck and in-use off-road emissions estimates for in-use diesel Rules, and category specific emissions estimates for ocean-going vessels, pleasure craft, and many other types of vehicles.


Current Methods and Data

ARB periodically releases multi-category inventories that provide a snapshot of emissions developed periodically for air quality planning purposes. These inventories are developed using methods that are integrated into database tools and models that can be found here. ARB also published emissions output periodically which can be accessed through on-line web tools that can be found here.

Previous Methods and Historical Documentation

Additional information is available for previous model versions, system documentation and archived information.

Resources


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