Multicriteria analysis on environmental impacts of accelerated vehicle retirement program from a life-cycle...

The environmental benefits of accelerated vehicle retirement programs (AVRPs), which have been extensively adopted in many countries, are highlighted by the proponents. However, the methods for evaluating their environmental effects are lacking of considering material and water criteria as well as continuous improvement in vehicle fuel efficiency and emission control. Additionally, the studies on Chinese case only considered air pollutants during vehicle usage and assumed a fixed remaining lifetime of old vehicles. This study therefore proposed a multicriteria life-cycle analysis model, which embeds not only vehicle lifetime distribution but also dynamics of vehicle fuel efficiency and emission factors, to examine the environmental effects of AVRP more comprehensively in terms of material, water, and energy consumption as well as emission of greenhouse gas, air pollutants and water pollutants. The assessment of the AVRP in Beijing, China, shows that short-term environmental benefits can be hardly gained from a life-cycle perspective, and energy consumption, greenhouse gases and other pollutants (except for volatile organic compound) decrease only when the users keep their new vehicles for 3 years or more. In the medium term, the AVRP would slightly increase material, energy and water consumption, sulfur-oxide, greenhouse gas and water pollutants, but significantly or moderately reduce other air pollutants. Moreover, the results reveal that merely considering the phase of vehicle usage may also lead underestimating some environmental benefits of AVRP by ignoring the phase of fuel production, whilst promoting vehicle fuel efficiency standards and the environmental regulations on vehicle and fuel supply chains may minimize the environmental benefits of AVRP or even have adverse effects.