IN SEARCH OF BETTER ROUTE GUIDANCE INSTRUCTIONS

Safety concerns have prompted designers of in-vehicle route guidance a nd information systems (IVRGIS) to make more use of an 'audible interf ace' to convey guidance instructions. Previous research has shown that , contrary to expectations, detailed guidance instructions can have a detrimental effect upon wayfinding performance, particularly for elder ly individuals. In response to these findings a second series of exper iments was carried out to try to improve the effectiveness of route gu idance. Using the same procedure, 40 male and 40 female drivers aged 1 8-35 years watched video footage of journeys through an unfamiliar are a, while hearing guidance that linked direction instructions to landma rks visible at the decision point. Results showed that those who heard these amended instructions performed significantly better than other groups at a wide range of tasks designed to measure the spatial knowle dge they had acquired. This group performed better than groups who hea rd nothing, and groups who heard full guidance. The results support th e view that, whereas full guidance instructions can have a negative im pact upon wayfinding performance, less complex instructions that link landmarks to directions have the capacity to enhance wayfinding perfor mance. This is because instructions of this form strengthen the associ ations made between directions to be taken and the spatial location of these turns, resulting in the formation of a strong representation of the route. The results also showed that those who had been driving fo r 1 year or less were significantly less accurate at these tasks than those with more driving experience. This result has important implicat ions for the widespread implementation and use of IVRGIS: suggesting t hat, for newly qualified drivers, who have not yet developed the abili ty to attend to and process information while controlling the vehicle, attending to route guidance instructions might have a detrimental eff ect upon driver safety.