On-Road Mobile Source Programs
This page last reviewed March 26, 2015
The California Clean Air Act (CCAA) mandates the Air Resources Board
(ARB) to achieve the maximum degree of emission reductions from all on-
and off-road mobile sources in order to attain the state ambient air
quality standards. On-road mobile sources include:
The On-Road Certification/Audit Section is responsible for the certification and production
audit of new passenger cars (PC), light-duty trucks (LDT), medium-duty vehicles (MDV),
heavy-duty engines (HDE) and vehicles (HDV) including urban buses (UB), on- and off-road motorcycles
(ONMC and OFMC), all-terrain vehicles (ATV), and electric golf carts (eGC).
Low Emission Vehicle Program
The Low Emission Vehicle Program area of the website includes all
recent information on the Low Emission Vehicle Program, including the
LEV II amendments.
On-Board Diagnostics (OBD) Program
On-Board Diagnostic (OBD) systems are incorporated into the computers
on-board new vehicles to monitor components and systems that affect
emissions when malfunctioning.
On-Road Heavy-Duty Vehicle Program
Emissions from on-road heavy-duty vehicles are major contributors to
poor air quality in California, in amounts highly disproportionate to
the numbers of these vehicles.
On-Road Motorcycle Regulation
Along with other motor vehicles, the ARB has identified on-road
motorcycles as a potential source of air pollution which can be reduced
On-Road Trucks (In-Use) Control Measure
All diesel fueled trucks, buses, trailers and transportation refrigeration units operating in California,
including those based out of state, have requirements to reduce air pollution and improve the state's overall air quality.
On-Road Medium- and Heavy-Duty Greenhouse Gas (GHG) Regulations
Phase 1 GHG
establishes new regulation for GHG emissions from heavy-duty trucks and
engines sold in California.
CA Phase 2 GHG regulations are being developed to achieve
further fuel economy improvements and GHG reductions beyond Phase 1.
Zero-Emission Vehicle Program
ARB is committed to the successful introduction of Zero Emission
Vehicles such as battery and fuel cell electric vehicles and is taking
steps to ensure the market is ready.