Turrentine, Thomas S., Martin E. Lee-Gosselin, Kenneth S. Kurani, Daniel Sperling (1992) Household Decision Behavior and Demand for Limited Range Vehicles: Results of PIREG, a Diary Based, Interview Game for Evaluation of the Electric Vehicle Market. Institute of Transportation Studies, University of California, Davis, Presentation Series UCD-ITS-RP-92-18
Electric vehicles (EVs) promise major improvements in air quality. But the limited range and long recharge times of EVs have created great uncertainty about consumer demand. Technical constraint studies find good news, that 20-60% of all households in the United states could substitute an EV with 162 km range for one of their current vehicles. In startling contrast, choice studies – based on the responses of consumers to hypothetical choice sets – find that limited range and long recharge are extremely expensive drawbacks and forecast sales of a few percent or less of the yearly new auto market. These studies have relied on meager data and not investigated the potential revolutionary effect on the automobile market of the introduction of alternative fueled vehicles.
To explore potential dynamics, we have conducted three linked studies: 1) a test drive of EVs, natural gas, and methanol vehicles by 236 citizens in Los Angeles (with 11 post-drive focus group interviews); 2) purchase intention and range simulation games (PIREG) and 3) interviews with over 100 owners of EVs. In this paper, we focus upon the methods and results of PIREG, an interview gaming technique derived from the CUPIG (Car Use Patterns Interview-Game) developed by Martin Lee-Gosselin to study future automobile use. The interview uses one week diaries of households and detailed descriptions of a recent vehicle purchase decision to create a realistic simulation context for examining the potential substitution of several new electric vehicle technologies.
The results demonstrate several dynamics. First, increased information and learning experience will reduce uncertainty in the EV market, affecting stated preferences. In the test drive, 76% of participants said their opinion of EVs improved after a test drive. Participants were surprised at how normal the EVs looked and performed. Second, households will consider adaptive responses to limited range vehicles, given the social benefits of clean air. Most PIREG participants were surprised at how easily electrics fit their travel needs; most were highly receptive to EVs if the price were equal to that of a gas car. Using detail diaries of their own car use, participants proposed simple ways of adapting to limited range including swapping vehicles for longer days, opportunity charging at work and in some households increasing the vehicle stock. In most cases, households preferred occasional adaptations to more expensive, long range vehicles. Finally, PIREG interviews and electric vehicle owner interviews suggest that a mUlti-fueled household (gasoline and electric) will optimize the EV use with significant fuel cost differences. In some cases, the ability of households to shift vehicle use to the EV was so significant, that it may offset the higher initial cost of EVs.