What Affects the Intention to Adopt Alternative-fuel Vehicles in California? 

Abstract
California is leading the way towards a more sustainable transportation system. The state aims to have 5 million zero-carbon emission vehicles (ZEVs) on the roads by 2030, including a mix of plug-in hybrid electric vehicles (PHEVs), battery-electric vehicles (BEVs) and hydrogen fuel-cell vehicle. Nowadays, more than 0.7 million ZEVs have hit the road in the state (1, 2). This figure is expected to increase more than sevenfold during the next decade. Understanding what factors influence people’s interest, adoption and usage of ZEVs would help policy makers develop more individually-tailored policy interventions to encourage the uptake. Moreover, identifying the regions with high concentrations of potential early adopters would inform the diffusion process, which has timely implications for policy decisions on where infrastructure programs to deploy.

Since ZEVs, especially PHEVs and BEVs, were introduced to the broader consumer market in 2010, there has been a growing number of studies exploring the motives for and barriers to their adoption (3–6). Those factors can be grouped into four main categories: a) regional context including policy incentives, energy prices, charging facility readiness, media influence, peer effects and etc., b) vehicle features including purchasing price, performance, battery range and etc., c) consumer characteristics including individual/household socio-demographics, vehicle ownership and purchasing plan, travel patterns, etc., and d) perceptions/attitudes towards technology and the environment.

Many previous studies have designed stated preference surveys with hypothetical choices to understand the market penetration of ZEVs. Instead, in this study we focus on choice making process and user behavior of early adopters through empirical data. This study analyzes a sample of more than 3,000 residents from all major regions in California, which includes a group of early ZEV adopters with rich information at the individual level. We hypothesize that different lists of factors may have come into play on people’s current choice and future interest of vehicle fuel type. We estimate hybrid choice models to understand the source of preference heterogeneity among individuals, taking into account their perceptions and attitudes on various topics. Model results help understand the unique characteristics of each latent market segmentation. We further hypothesize that consumers’ current choice may also influence their future intention, namely, their existing user experience may impact their future ‘stickiness’ to vehicles with alternative fuel vs. interest in adopting one. Preliminary results suggest that current ZEV users report much higher interest in continuing to buy/lease ZEV, while several barriers exist for non-users, attributable to a mix of lack of knowledge/awareness and the role of several individual characteristics and vehicle features.

Encouraging the adoption of alternative-fuel vehicles has emerged as a mainstream policy interest in California, but many barriers remain to meeting the ambitious environmental and emission targets of the state. By modeling vehicle adoption behavior at the regional level, this study expands our understanding of the factors relating the motives and barriers of ZEV transition. Thus, it supports the development of better-informed policies to remove eventual barriers and encourage various groups of users to transition to ZEVs, and ultimately promote transportation sustainability.