Survey of best practices in emission control of in-use heavy-duty diesel vehicles

This paper focuses on ways to reduce the emissions of the in-use vehicle fleet, with particular emphasis on heavy-duty diesel trucks, due to their disproportionate contribution to both urban air quality and greenhouse gas emissions. The report surveys measures that are in effect across the world, including programs that help identify vehicles that disproportionately contribute to overall emissions; administer inspection, maintenance, and in-use emission testing protocols to help eliminate gross-emitting vehicles; assist in the effective deployment of retrofit emission control technology; and promote improved fuel quality to directly reduce emissions and facilitate improved emission control technology. The work highlights a number of national, regional, and local examples of effective emission control programs that exhibit best practices from around the world. The report concludes by summarizing the critical actions that can be undertaken at national and local levels to install world-class emission control programs for in-use heavy-duty vehicles.