Measuring and Modeling Future Vehicle Preferences: a Preliminary Stated Preference Survey in Maryland
C Cirillo, M Maness, University of Maryland, US
This paper proposes the estimation of future demand for new technology vehicles under greater competition in energy markets and innovative policies.
Over the near term, the culmination of new vehicle technologies, greater competition in energy markets, and government policies to fight pollution and reduce energy consumption will result in changes in the vehicle marketplace. Understanding the impact of these factors, through the use of vehicle ownership modeling, is critical for achieving a country's environmental and economic goals. This project proposes to create a stated preference survey along with discrete choice models to predict future demand for battery electric, plug-in hybrid and normal hybrid electric, alternative fuel, and gasoline vehicles over the short to medium term.
The survey is divided into four parts: socioeconomics, attitudes, current vehicles, and stated preference sections. The socioeconomics portion asks respondents about themselves and their households. The attitudes section collects information on respondents' attitudes and belief about vehicles and elements of their social interaction with family and acquaintances and the media. The current vehicles portion asks about the households' current vehicles ownership and reasons for purchase.
The stated preference section presents respondents with various dynamically changing hypothetical scenarios annually over a future five-year period using one of two game designs. The designs correspond to (1) changing vehicle technology and pricing and (2) changing fuel pricing and availability. Over the course of the choice games, the vehicle and fuel attributes dynamically change to mimic changes in the marketplace. With these changes to the vehicle marketplace, respondents are asked whether they will keep or replace their current vehicles and what type of new vehicle they would buy if preferred. This allows for vehicle and fuel prices to increase while technology progresses (e.g. fuel economy increases). The survey incorporates the phasing out (e.g. income tax credit) and introduction (e.g. vehicle-miles traveled tax) of policies as well. This type of design allows for determining not only the conditions that would encourage or discourage new vehicle adoption, but also the process of households waiting for the appropriate conditions in a dynamically changing landscape.
A preliminary trial of the survey was conducted from September to October 2010 in the State of Maryland with a sample size of 141 respondents. To facilitate the design and administering of the survey, a web survey framework, JULIE, was created specifically for creating stated preference surveys. Using JULIE, the survey was conducted using computer-assisted self interviews (CASI) and web-based modes. Using the stated preference results from this preliminary trial, a multinomial logit model is used to estimate future vehicle ownership by vehicle type. The full-scale survey is being conducted during late Winter 2011. The preliminary models show that the survey design allows for estimation of important parameters in vehicle choice. Preliminary results found consumer interest in plug-in hybrid electric vehicles with a two- to three-time increase in gasoline prices and a lesser interest in alternative fuel vehicles. Increasing fuel economy in gasoline vehicles did not encourage consumers to buy newer more fuel efficient conventional vehicles. We also found that a green VMT (vehicle miles traveled) tax could generate interest in electric vehicles. The analysis showed that most recently planned vehicle offerings for electric vehicles are not sufficient for significant market penetration over the short term. Respondents' concerns over vehicle emissions did not significantly influence purchasing decisions.
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