Good vibrations: Using a haptic accelerator pedal to encourage eco-driving

- An evaluation of vibrotactile information presented through the accelerator pedal.
- Enhanced coasting phases can be supported, with high user acceptance.
- Mean simulated fuel savings of around 11% were supported.
- Stimulus timing shown to be important, for acceptance and for system effectiveness.
- Devices should allow self-selection of timings, but have a minimum time-to-event limit.

This article presents the experimental analysis of an in-vehicle, vibrotactile eco-driving support system, focussed on encouraging maximisation of the coasting phase of the vehicle when approaching slowing or stopping events in order to take advantage of vehicle momentum. The simulator study assessed the effects of three different time-to-event stimulus timings (four, eight, and twelve seconds) on objective driving performance metrics, and on subjective measures of acceptance, ease of use, and intention to use. The shortest time-to-event had a marginally damaging effect on performance, and was not well received by participants. Both medium and long time-to-event stimuli performed well on subjective measures, and both facilitated increased eco-driving performance. The longest lead-time stimulus was the most effective, resulting in an 11% simulated fuel saving compared to baseline. Findings are discussed in terms of the importance of the timing of information, and regarding the need for longer-term research on the potential effects of system failure on performance and safety.