Further evidence for benefits of verbal route guidance instructions over symbolic spatial guidance instructions

This paper reports a study that investigated how to present simple guidance instructions in a car. The literature suggests an advantage for oral over visual information because the visual channel is already heavily loaded while driving. Earlier research suggested that this was due to the fact that verbal instructions are better suited than spatial symbols (arrows) on a visual display. The major aim of the present study was to replicate this finding and to test explanations for this phenomenon in order to come to more sophisticated guidelines. The results confirm the advantage of verbal instructions and suggest that it is caused by recoding of spatial guidance instructions into a verbal memory format which is not required for verbal instructions. It is concluded that navigation instructions should basically be oral although arrows or map-like images may be used to support oral presentation.