Design and evaluation of a vibrotactile seat to improve spatial awareness while driving

In this paper, we describe the design and evaluation of a vibrotactile driver's seat that is used to display spatial information during two driving tasks. Many studies have recently shown the effectiveness of haptic and vibrotactile feedback to augment collision warning systems in automobiles. Simultaneously, driver distraction and situational awareness have been identified as significant safety issues in all areas of transportation. We hypothesize that vibrotactile feedback may be used to enhance and improve spatial awareness while driving if it is used continuously and naturally so that it is part of the normal operation of the automobile. We designed a tactile feedback seat from low cost pager motors and characterized the spatial resolution of the seat. We then developed a driving simulation in which the location of vehicles behind and next to the driver's vehicle is communicated through vibrotactile feedback from the seat back. The effectiveness of the seat was evaluated in two driving tasks designated commuting and racing. In the commuting exercise, the test subjects (N=12) maintained a target speed while simultaneously avoiding other vehicles and performing a secondary task. A "near-miss" blind spot recording method was used to evaluate the effect of the feedback in reducing hazard exposure. In the racing exercise, the test subjects (N=10) raced other virtual competitors while using the feedback to maintain awareness of other vehicles in close proximity. Effectiveness was measured by comparing the accumulated time that cars were blocked behind the driver's car. Three feedback conditions were tested: only vibrotactile feedback, rear view mirror and vibrotactile feedback, rear view mirror only. Our preliminary results showed that vibrotactile feedback used in conjunction with the rear view mirror improved performance over using just the rear view mirror. We discuss some of the challenges of creating driving simulations and evaluation metrics that are both realistic and repeatable.