Project at a Glance

Title: Measurement of In-Use Emissions and Field Consumption from Vocational Heavy-Duty Vehicles with Conventional and Alternative Engine and Fuel Technologies in Southern California

Principal Investigator / Author(s): Leonard, Mary

Contractor: South Coast Air Quality Management District

Contract Number: 16RD012


Research Program Area: Emissions Monitoring & Control

Topic Areas: Greenhouse Gas Emissions, Mobile Sources & Fuels


Research Summary:

Current heavy-duty engine emission standards have reduced both oxides of nitrogen (NOX) and particulate matter (PM) emissions significantly in the South Coast Air Basin (SoCAB). However, it is projected that heavy-duty vehicles (HDV) will still be a dominant source of those emissions in the SoCAB and there is a need of additional reduction in NOX emissions to meet National Ambient Air Quality Standards (NAAQS) for ambient PM and Ozone. Understanding the impact of conventional and alternative engine and fuel technologies on in-use emissions and fuel use is critical for developing State Implementation Plans (SIP) as well as for understanding the effectiveness of potential rules to further lower emission standards for HDVs.

The South Coast Air Quality Management District (AQMD), California Energy Commission (CEC), Southern California Gas Company (SoCal Gas), and California Air Resources Board (ARB or Board) jointly developed a research plan for collecting in-use vehicle activity, emissions, and fuel use data from up to 200 HDVs in various vocation types including goods movement, transit bus, school bus, refuse, and local delivery and for developing effective strategies to achieve the NAAQS requirements in the region. ARB will participate in this project as a co funding organization.

Our current research investigations characterizing HDV activity profiles by vocation and quantifying the potential greenhouse gas (GHG) benefits of aerodynamic features on HDV use only onboard diagnostic (OBD) data and do not include measurements of in use emissions and fuel use due in part to limited resources. We will use the findings from this research work to expand our understanding of vocational use of HDVs and to develop effective strategies for achieving the federal ambient air quality standards and the state GHG reduction goals.


For questions regarding this research project, including available data and progress status, contact: Research Division staff at (916) 445-0753

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