Best Practices in Reducing Emissions through Vehicle Replacement Programs

by Kristine Smukste - 19 March, 2015
New report from the ICCT

The International Council on Clean Transportation (ICCT) has published a new report on an important facet of vehicle emissions reduction – programs to replace old vehicles that contribute a disproportionate share of pollution.

The report, issued March 9, evaluates eight vehicle replacement programs from around the world and identifies five best practices in the areas of program design and implementation, as well as fiscal incentives and policies, to serve as guidelines for policymakers.

In many regions of the world, older, high-emitting vehicles account for a small percentage of the overall vehicle fleet but a disproportionately large share of total emissions. These vehicles may be responsible for more than 50% of particulate matter and black carbon emissions by 2020.

A variety of emission control programs have been developed to reduce emissions from these legacy, high-emitting vehicles. Vehicle replacement, retrofit, and repower programs can have an immediate impact because they reduce emissions from inefficient vehicles in the fleet within a short period of time. Positive environmental impacts can be achieved with the reduction of gaseous pollutants (CO, HC, NOx), as well as of particulate matter. Greenhouse gas emissions are also reduced, especially of short-lived climate pollutants such as black carbon, one of the main components of particulate emissions.


The report focuses primarily on one element of that array of policy options, vehicle replacement programs, which seek to replace older and gross-emitting vehicles with newer, more efficient, and environmentally friendly vehicles. The five best practices include:

  • For maximum environmental benefits, replacement vehicles should be as clean as possible.
  • Program implementation, management and enforcement should ensure expected benefits are actually achieved
  • Fiscal incentives should be carefully tailored to optimize both environmental benefits and cost-effectiveness
  • Program design should carefully consider and balance the different roles of national, regional and local-level policymakers
  • Complement fiscal policies with additional incentives such as low emission zones and regulatory backstops.


The ICCT is a partner of the CCAC and is a lead partner of the CCAC’s Heavy-Duty Diesel Initiative. The Initiative aims to catalyze major reductions in black carbon through adoption of clean fuel and vehicle regulations and supporting policies. The work entails laying the technical and political groundwork that will enable global black carbon emission reductions from new and in-use vehicles by developing (a) a global fuel sulfur strategy that addresses the major hurdles facing low sulfur fuels today, from financing to obstructive subsidies and political inertia, (b) national programs to address emissions from the existing vehicle stock, including retrofits, scrappage, inspection and maintenance, and (c) a high-level coalition of industry, country and NGO leaders in support of the Green Freight Call to Action to improve the energy efficiency and environmental performance of freight operations worldwide.