Public Workshop to Discuss Updates to CARB’s EMFAC Model

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September 13, 2022

Public Workshop to Discuss Updates to CARB’s EMFAC Model

The California Air Resources Board (CARB) invites you to participate in a workshop on Wednesday, October 12, 2022, to discuss updates to CARB’s official on-road mobile source emissions inventory model, EMFAC. At the workshop, which will be the first of a series of workshops, staff will introduce potential updates to methodologies and data sources for the next version of the model, EMFAC202Y. The most recent version of the model is EMFAC2021 (v1.0.2).

This public workshop will be held via Zoom at the following date and time. Interested parties must register to participate. After registering, participants will have the option to participate via the Zoom software platform or access the meeting by telephone with dial-in instructions. There will be no in-person attendance for this workshop. CARB staff highly recommends participating using the Zoom Desktop or Mobile App to see and hear the presentation in a single platform while participating in the event. This meeting will be recorded.

Date:                Wednesday, October 12, 2022
Time:                9:00 a.m. – 4:00 p.m. (Pacific Time)
Call-In #:          (888) 363-4734 
Passcode:        350021


Tentative Agenda

9:00 am: Introduction and Background

9:30 am: Summary of Major Updates – Part I

12:00 pm: Break (60 minutes)

1:00 pm: Summary of Major Updates – Part II

3:30 pm: Closing Remarks and Final Q&A

The time allocated for each topic includes time for questions from participants.  All times listed above are provisional and will depend on the amount of questions and discussion. Workshop materials will be posted in advance of the workshop on CARB's Mobile Source Emission Inventory (MSEI) webpage.


The EMFAC model is the primary tool that CARB uses to assess emissions from on-road motor vehicles including cars, trucks, and buses in California for regulatory and planning efforts. For example, CARB recently used EMFAC to support multiple incentive programs and regulations, and to develop planning documents including the Mobile Source Strategy and the State Strategy for the State Implementation Plan. To better estimate and evaluate the impact of various incentive programs and regulations and to support future air quality planning, CARB needs to update mobile source analysis tools with the most up-to-date data and methodologies. In addition, as the transportation sector in California is transitioning to zero-emission technologies under the direction of the Governor’s Executive Order N-79-20, the current capacity of EMFAC needs to be expanded.

The tentative release for EMFAC202Y will be in 2024 or later, and this workshop will be the first of a series of workshops to discuss the initial updates to the model. Subsequent workshops in 2023 and 2024 will cover more updates on methodologies and explain differences between the new estimates and those from the current version of the model, EMFAC2021. Please join the MSEI e-mail list to stay informed of future EMFAC developments and public meetings.


For more information or questions on EMFAC, please contact us at

Special Accommodation Request

Consistent with California Government Code Section 7296.2, special accommodation or language needs may be provided for any of the following:

  • An interpreter to be available at the meeting;
  • Documents made available in an alternate format or another language;
  • A disability-related reasonable

To request these special accommodations or language needs, please contact Dr. Satya Sardar (Tel: 951-542-3376) as soon as possible, but no later than five business days before the scheduled meeting. TTY/TDD/Speech to Speech users may dial 711 for the California Relay Service.