Air Quality Planning and Science Division

On-Road (EMFAC)

 The EMFAC emissions model is developed and used by CARB to assess emissions from on-road vehicles including cars, trucks, and buses in California, and to support CARB's regulatory and air quality planning efforts. US EPA approves EMFAC for use in State Implementation Plan and transportation conformity analyses.

EMFAC Web Platform
EMFAC2025 Model

EMFAC2021 Model

EMFAC2017 Model

EMFAC2014 Model and Older

Emissions Inventory Support for Regulations

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Conferences and Workshops - Conferences

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This page lists the public conferences hosted by the Mobile Source Analysis Branch (MSAB) to support emissions inventory development.

On-Road (EMFAC)Off-Road ModelsConferences
EventsPresentations
Onboard Sensing, Analysis, and Reporting (OSAR) Conference hosted by the University of California Riverside (UCR) College of Engineering, Center for Environmental Research and Technology (CE-CERT) - March 14 & 15, 2024

34th Coordinating Research Council (CRC) Real World Emissions Workshop - March 2024

AGU2023 Fall Meeting - December 2023

Symposium of California Air Pollution Control Officers Association (CAPCOA)Planning Managers Committee - November 2023

Onboard Sensing, Analysis, and Reporting (OSAR) Conference hosted by the University of California Riverside (UCR) College of Engineering, Center for Environmental Research and Technology (CE-CERT) - March 2023

Coordinating Research Council (CRC) Real World Emissions Workshop - March 2023

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Current Activities

In addition to maintaining the mobile source emission inventories, MSEI staff performs additional technical work that informs air quality policy for California. This page provides a list of programs, resources, and efforts that mobile source inventory staff leads or supports.

Activity DescriptionProgram Link
Senate Bill (SB) 1 Report - Among other provisions, SB 1 states that as of January 1, 2020, the California Department of Motor Vehicles (DMV) must check that vehicles are compliant with, or exempt from, CARB’s Truck and Bus Regulation prior to being registered to operate in California. MSEI staff is leading this report that is due to the legislature by January 1, 2025, and coordinating with regulatory teams.

SB 1 Report

2020 – 2022 San Pedro Bay Port Congestion - Ports in California experienced a substantial increase in cargo imports, resulting in significant congestion at terminals and in surrounding areas. This has led to emissions increases from freight-related sources which can negatively impact air quality especially in communities near the ports of Los Angeles and Long Beach (collectively the San Pedro Bay Ports). The following documents detail the emission impacts from freight related sources due to this congestion.

Port Congestion Impacts

Smog Check Certification - California Air Resources Board staff prepared the California Smog Check Performance Standard Modeling (PSM) and Program Certification for the 70 parts per billion (ppb) 8-hour Ozone Standard (referred as “Smog Check Certification”) to address State Implementation Plan (SIP) requirements of the federal Clean Air Act (CAA, or the Act) for ozone nonattainment areas within the State.

Smog Check Certification

Emissions Surveillance Testing - CARB’s vehicle surveillance programs (VSP) for light-duty passenger vehicles (LD), light-heavy duty vehicles (LHD), Motorcycles (MCY) and truck and bus surveillance programs (TBSP) for heavy-duty trucks and buses are conducted to collect emissions data used to model the statewide in-use fleet and develop the emissions inventory. The test data collected from VSP and TBSP is used to update the state’s EMission FACtor model (EMFAC) for base exhaust emission rates, start emission rates, evaporative emission rates, deterioration rates, vehicle speed correction factors and other correction factors needed for emissions inventory development.

LD VSP

LHD VSP

MCY VSP

Class 4-6

TBSP 7-8

Smog Check/Random Roadside Failed Vehicles Test Program

Mobile Source Strategy - The State of California has many air quality, climate, and community risk reduction goals to achieve over the next thirty years. CARB staff developed the 2020 Mobile Source Strategy to take an integrated planning approach to identify the level of transition to cleaner mobile source technologies needed to achieve all of California’s targets. Mobile sources and the fossil fuels that power them continue to contribute a majority of emissions of diesel particulate matter as well as smog.

2020 Mobile Source Strategy

Off-Road Advanced Clean Equipment - This web page is a showcase of zero-emission off-road equipment (known to CARB) that are currently available in the market or are in various stages of research, development, or demonstration. By sharing this list, CARB's staff intends to achieve the following objectives:  Demonstrate progress in off-road zero-emission equipment availability, provide a comprehensive reference of zero-emission off-road equipment for incentive or regulatory strategies, and introduce alternative charging options and strategies.

List of Equipment

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Conferences and Workshops - Off-Road Models

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This page lists the public workshops and webinars hosted by the Mobile Source Analysis Branch (MSAB) in support of the OFF-ROAD emissions inventory development.

On-Road (EMFAC)Off-Road ModelsConferences
March 2026 Public Workshop for Recreational Marine Vessel (RMV2026) Emissions Inventory Model
July 2025 Public Workshop for Updates to the Transport Refrigeration Unit (TRU) Emissions Inventory Model
December 2024 Public Workshop for Draft Ocean-Going Vessels Emissions Inventory Model
October 2024 Public Workshop for the Development of the 2024 California Aircraft Emissions Inventory Model (CAI2024)
October 2023 Second Public Workshop for Tier 5 Rulemaking Inventory on Preliminary Off-Road Diesel Emission Factor Updates
January 2023 Second Public Workshop for Large-Spark Ignition Forklift Emissions Inventory
April 2022 Public Workshop for Large-Spark Ignition Equipment Emissions Inventory
September 2021 Public Workshop for Cargo Handling Equipment and Ocean-Going Vessels Emissions Inventories
March 2021 Public Workshop for the Development of the California Recreational Marine Vessel Emissions Inventory
September 2020 Public Workshop for Locomotive Emission Inventory
April 2020 SORE2020 Model Webinar - Q&A
March 2020 Public Workshop for SORE2020 Model
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Conferences and Workshops - On-Road (EMFAC)

                                                                                                                                                                    < BACK TO CONFERENCES AND WORKSHOPS

This page lists the public workshops and webinars hosted by the Mobile Source Analysis Branch (MSAB) in support of the ON-ROAD emissions inventory development (EMFAC).

On-Road (EMFAC)Off-Road ModelsConferences
April 30, 2025 Public Workshop for the EMFAC202Y (EMFAC2025) Model
October 23, 2024 Public Workshop to Discuss Updates to CARB's EMFAC202Y (EMFAC2025) Model
January 17, 2024 Public Workshop for the EMFAC202Y (EMFAC2025) Model
October 2022 Public Workshop for the EMFAC202Y (EMFAC2025) Model
December 2020 Public Workshop on the EMFAC202x (EMFAC2021) Model
July 2020 Public Workshop on the EMFAC202x (EMFAC2021) Model
October 2019 Public Workshop on the EMFAC202x (EMFAC2021) Model
June 2017 Public Webinar Workshop on Updates to CARB'S EMFAC2017 Model
June 2015 EMFAC2014 Online Training Webinar 

 

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