Guerilla evaluation of truck HMI with VR

HMI development requires user centered testing of HMI prototypes in realistic scenarios. Typical problems are the acquisition of a representative user group and the setup of realistic scenarios. The paper describes the method of Guerilla interviews on truck stops along highways in order to approach truck drivers as participants in a user centered HMI development process. A truck steering wheel with cluster display mockup from earlier on-site interviews was compared to a new virtual reality (VR) truck cockpit simulator. The Guerilla method proofed its value to involve truck drivers in HMI evaluation as a fast and efficient approach, as long as mobile HMI prototypes are available. As a limitation of the Guerilla method we found the time limits given by the strict truck drivers' break time and little control of the participant sample. Regarding the HMI prototype comparison, we conclude that the steering wheel mockup still requires less efforts and costs for testing, however the VR simulator shows a better context representation for the function and hence better external validity of the results. Slightly longer test duration of the VR simulator is mainly attributed to the time for introducing the new technology to participants. The outlook describes how the mobile VR simulator is further developed to overcome its limitations.