In-Vehicle Auditory Display of Symbolic Information

Abstract

Using the Federal Highway Administration Sign simulation laboratory, 24 participants were presented with roadway sign information using either computer-controlled graphic images or audio recordings. The road signs selected for display contained either symbolic or text-based messages. Following visual or auditory presentation of the information, participants were asked to identify if the displayed message matched a projected sign image. Performance accuracy and recognition times for projected signs were measured. Overall, driver response time was found to be longer for text-based messages than for symbolic messages but this difference was not affected by the type of display used to present the message. Matching tasks that paired auditory display of sign names with symbolic sign images did not result in longer recognition times or increased errors. Presenting drivers with verbal information to inform them of symbolic road signs was as effective as presenting them with graphic visual images of the signs.