Comparison of portable and onboard navigation system for the effects in real driving

Navigation systems are very useful and popular tools which display a user’s location and make use of graphics, text and voice information to guide him to a predetermined destination. Recently, some researches had revealed that drivers choose to receive driving directions using portable devices owing to their price and convenience. This study aimed to survey whether the driving efficiency and controlling are different as using portable and onboard navigation systems. A smartphone (2.7″ screen) and driving support system we instructed (8.9″ display interface) were adopted as the portable and onboard navigation systems respectively. Thirty subjects were paid to participate in this study, and field experiments were executed in urban and rural environments. Participants were randomly divided into two groups with equal numbers and drove according to instructions provided by one of these systems. The results indicated that the performance of drivers using the portable navigation system is better than that of the onboard one, in terms of efficiency and car handling, both in the urban and rural environments, despite the fact that the display screen of the phone is so small.