Encouraging eco-driving : the case for vibrotactile information presented through the accelerator pedal

different methods of in-vehicle information presentation to encourage fuel efficient driving behaviours, and to explore the theoretical justifications for the use of in-vehicle haptic stimuli (related to the sense of touch), presented at the site of control (i.e., the accelerator pedal). A review of the literature concerning design, behaviour, and energy use led on to an exploration of Ecological Interface Design, and the Skills, Rules, and Knowledge (SRK) taxonomy of human behaviour, particularly with regard to haptic information presented through the accelerator pedal. Survey and on-road studies served to shed light on the practice of eco-driving more generally, in terms of attitudes, knowledge, behaviour, and cognition. Then followed an analysis of expert eco-drivers’ decision-making processes. This made use of the decision ladder, an analysis tool rooted in the SRK framework. Results of the analysis went on to inform the design of an in-vehicle information system that aimed to support optimum use of the accelerator pedal, both for efficient accelerations, and for maximisation of the coasting phase of the vehicle when approaching deceleration events. A simulator-based experiment served to assess the effects of presenting stimuli in different sensory modes (visual, auditory, vibrotactile), resulting in the conclusion that vibrotactile feedback, being both effective and well received by participants, is indeed suitable for the support of eco-driving. In a second simulator-based study, coasting support provided the sole focus; acceleration behaviours were not investigated. Results suggested that there is a minimum distance away from an event below which stimuli encouraging removal of the foot from the accelerator pedal (in order to coast down to the desired speed)have neither a beneficial effect on driving performance, nor attract positive acceptance ratings from users. Moreover, stimuli presented farther from the event supported greater benefits in terms of efficiency. Overall findings are discussed with regard to the practical aspect of how best to support eco-driving in the private road vehicle, and in relation to the theoretical justifications for accelerator-based haptic feedback in the vehicle.