The authors of this report evaluate eight vehicle replacement programs from around the world, and they identify five best practices in the areas of program design and implementation, as well as fiscal incentives and policies, to serve as guidelines for policymakers. The authors focus on replacement programs to replace older and gross-emitting vehicles with newer more efficient and environmentally friendly vehicles to reduce for transport sector emissions of greenhouse gases, particulate matter, and the pollutants CO, HC, and NOx.