Review of Current Practices and New Developments in Heavy-Duty Vehicle Inspection and Maintenance Programs

This report evaluates inspection and maintenance (I/M) programs designed to identify and mitigate high emissions. The report focuses on heavy-duty vehicles (HDV) which globally produce 40-60 percent of nitrogen oxide and particulate matter on-road emissions. It discusses the state of the practice in I/M testing methods and identifies best practices. It also looks at new developments in testing protocols, on-board diagnostics (OBD), and remote sensing. Current practices in I/M programs are presented for Australia, Canada, China, Europe, Hong Kong, California, and Colorado. The report concludes with recommendations for improving I/M testing and programs in the future.