Roadside Emissions Data Collection

The Bureau of Automotive Repair (BAR) established the Roadside Inspection Program, as provided in Health and Safety Code section 44081, to audit the emissions of vehicles being driven on California roadways. The program is conducted with assistance from the California Highway Patrol (CHP). Data collected during roadside surveys serves as a baseline and helps the state measure its progress towards meeting federal emission reductions standards. This data also provides useful information to evaluate and improve the overall performance of the Smog Check Program.

Roadside surveys are performed in areas of the state with the poorest air quality or that contribute to other areas with poor air quality, including the Central Valley, San Francisco Bay Area, greater Los Angeles area, Inland Empire, and San Diego area. Participation in the program is voluntary and there are no consequences to consumers, regardless of the vehicle's emission levels or state of its emission control systems.

The Roadside Inspection Program was recently expanded to include model-year 2016 vehicles to ensure the most current and accurate data is collected. Various safety enhancements have also been implemented, including restructuring the survey lane setup, to ensure the safety of all participants including BAR, CHP, and the motoring public. More information is available on the Roadside Inspection Program page at

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