Accelerating vehicle fleet turnover to achieve sustainable mobility goals

Abstract

Achieving societal climate goals requires rapid reductions in greenhouse gas (GHG) emissions from transportation. Recent efforts by policymakers have focused on increasing consumer adoption of electric vehicles (EVs). Nevertheless, EV sales remain low. Worse, even if EV market share jumped dramatically, it would take decades to replace the existing vehicle fleet, during which time vehicle GHG emissions would continue, worsening climate change. Consequently, some argue for policies to accelerate the retirement of inefficient fossil-powered vehicles through "cash-for-clunkers" (C4C) programs. We examine C4C policies through a behavioral model of vehicle fleet turnover and EV market development in the United States. We find C4C policies can substantially reduce vehicle fleet emissions at reasonable cost per tonne of CO 2 . To meet emissions reductions goals, C4C policies should apply only when consumers replace their fossil-powered vehicles with EVs. C4C policies incentivizing EVs accelerate cost reductions through scale economies, charging infrastructure deployment, model variety, and consumer awareness, boosting EV adoption beyond the direct effect of vehicle replacement. The result is a substantial synergy amplifying the impact of C4C and lowering unit cost of emissions reductions. C4C is further amplified when deployed together with complementary policies promoting renewable electricity production and a gas tax or carbon price.

City-scale analysis of annual ambient PM2.5 source contributions with the InMAP reduced-complexity air quality model: a case study of Madison, Wisconsin

“…When calculating total percent reductions in ambient PM 2.5 versus population-weighted PM 2.5 we find similar percent reductions. In reality, emissions reductions would depend on which internal combustion engine vehicles were being replaced; EVs replacing old and inefficient internal combustion engine vehicles would have the largest impact, a replacement which can be accelerated by incentivization programs such as the 'cash-4-clunkers' program (Naumov et al 2022).…”

Do voluntary environmental programs matter? Evidence from the EPA SmartWay program

“…While our analysis is focused on truck age, we are not suggesting an optimal retirement age of trucks. One approach to evaluate the optimal retirement age would be to perform a total life cycle assessment using a math‐modeling or simulation analysis (e.g., Naumov et al (2022), Qiao et al (2019), Tan and Blanco (2009), and Yang et al (2020)). We discuss possible approaches in detail in the online appendix S1.…”

Introduction to the special issue on mobility, climate change, and economic inequality

“…This paper is a good example of how OM scholars, with their extensive research experience in transportation systems, can support policy initiatives aimed at increased sustainability and economic equality. Naumov et al (2022) study "cash-for-clunkers" (C4C) policies designed to accelerate the adoption of electric vehicles in the US. They suggest that C4C policies can considerably reduce vehicle fleet emissions at a reasonable cost per ton of CO 2 .…”

“…Naumov et al (2022) study “cash‐for‐clunkers” (C4C) policies designed to accelerate the adoption of electric vehicles in the US. They suggest that C4C policies can considerably reduce vehicle fleet emissions at a reasonable cost per ton of CO 2 .…”