CARB regulates emissions from mobile sources operating within California, including vehicles or equipment registered out-of-state. Mobile sources include light-duty vehicles (LDV), heavy-duty vehicles (HDV), and off-road equipment (ORE). They emit the majority of smog-forming oxides of nitrogen (NOX), represent the largest share of greenhouse gas (GHG) emissions, and are a major source of toxic air contaminants that pose serious health risks to communities. Recognizing their substantial impact on air quality and climate, CARB’s Research Program has long prioritized research on mobile sources. While the focus is on California, many of the research findings have broader relevance and can inform efforts in other jurisdictions.
Mobile sources research initiatives include:
Long-term trends in NOX and greenhouse gas emissions
Advances in mobile source monitoring
Understanding mobile source emission disparities
Activity and vehicle energy analysis
Controlling and monitoring off-road in-use emissions
Incentives, zero-emission vehicles, and charging infrastructure
