Recently, in-vehicle highly intelligent information devices are rapidly widespread. Under such circumstances, the accurate evaluation of the effect of display information and switch type on driving performance is important in order to develop in-vehicle information devices that do not menace the safety. In this article, we present a basic idea to estimate properly the effect of the vehicles display information and the switch system on driving performance. We compared the index such as mean task completion time, subjective rating on usability, tracking error, and NASA-TLX workload between young and older adults. The results suggest that young will be better than older adults at both abilities on processing displayed information and operating the switch. We were found that there was a significant interaction between the switch types and installation location. On the other hand, the displayed information did not affect the performance.