Live traffic camera content in the connected car: Experiences from motorway experiments

Today´s in-car driver information systems are offering a wealth of multimedia presentation features, which are relying on increasing amounts of available real-time traffic information. Such systems need to efficiently deliver safety-relevant information, but they should not overstrain the driver with too much detail. We present two user studies on the motorway to explore the impact of using live traffic content as a preview of the traffic situation ahead on the motorway. Our study showed that neither drivers did not look more often on the Human-Machine Interface (HMI) screen, nor did they display significantly less safe driving behaviors. In fact, drivers did not take too much notice of the in-car traffic content, as they tended to focus on the driving task. Our results also indicate that the impact of traffic pictures is partly mediated by the presence or absence of auditory instructions. When audio instructions were available, subjective comprehensibility did not differ between recommendations with or without traffic pictures. By contrast, when audio instructions were not presented, comprehensibility was rated lower for messages with traffic pictures than without. A further finding is that drivers recognized the displayed traffic situation better in the smartphone than in the large-screen setup. This was probably due to the fact that the multimedia contents were shown in full-screen mode on the smartphone. Regarding subjective preference, users had moderate interest for using traffic camera content while driving. A specific comparison with regard to the preference of traffic formats showed that abstract animations tended to be perceived as less distracting, but realistic contents such as videos were perceived as slightly more attractive with regard to hedonistic aspects of user experience. Implications for design and further research are discussed.