Emission Saving Potentials of Accelerated Vehicle Retirement Programs: A California Heavy-Duty Trucking Case Study

摘要

California is the largest consumer of transportation fuels in the United States. Anincreasing fraction of these fuels (25-29%) is dedicated to powering heavy-duty trucks,which has significant effects on both local air quality and greenhouse gases (GHG).Following the passage of the Global Warming Solutions Act (2006), the California AirResources Board (ARB) has commenced many heavy-duty trucking initiatives to assistin meeting the goal of obtaining an 80% GHG reduction from 1990 levels by 2050.Along with these initiatives, which include fuel reformulation and programs to promotemode switch, the ARB has instituted an accelerated vehicle retirement program (AVRP)(referred to as ”Cash for Clunkers”) to subsidize the removal of older, more pollutingheavy-duty trucks from California's fleet. The purpose of this study is to develop amodel for and report on the emissions savings potentials of truck-specific AVRPsconsidering the emissions generated through vehicle manufacturing, operation,maintenance, and disposal life-cycle phases. Our results indicate that the distribution oflifetime vehicle miles traveled (VMT), useful years of replacement, and fuel economy arekey parameters that influence AVRP emission assessments. Accelerated vehicleretirement programs in California can generate enough emissions savings to effectivelyoffset the lifetime GHG footprint of a portion (1-4%) of the participating heavy-duty trucks(Class 8), a GHG saving potential of upwards of 200,000 metric tons of carbon dioxideequivalents per 1,000 vehicles replaced.