UC Davis Institute of Transportation Studies

By easily comprehending their own energy consumption, individuals can make both individually and socially responsible choices. How and when that potential translates into actual choices is explored, first by using mile-per-gallon fuel economy as a metric for driver feedback and finding that the metric is unable to transmit accurate information about the impact of driving style on energy use. An alternative energy economy metric, the theory of planned behavior, is tested against driver responses to an existing feedback system available in the 2008 model Toyota Prius. It appears that driver responses support the use of behavioral theories to both measure and design feedback systems. A novel feedback design based on behavioral theories and drivers' responses to the feedback is presented. The quantitative results of a year long study of fuel economy in response to feedback finds the novel feedback design generates a statistically significant increase in fuel economy overall. The feedback also influences drivers' goals and attitudes. This finding supports the underlying behavioral theory and suggests that energy related behavioral decisions are dependent on the quality and behavioral relevance of information that people have about their choices and the resulting consequences.