Trip planning and in-vehicle navigation are crucial tasks for easier and safer driving. The existing navigation systems are based onmachine intelligence without allowing human knowledge incorporation. These systems give turn guidance with abstract visual instruction and have not reached the potential of minimizing driver's cognitive load, which is the amount of mental processing power required. In this paper, we describe the development of a multimedia system that makes driving and navigation safer and easier by offering tools for route sharing in trip planning and video-based route guidance during driving. The system provides a multimodal interface for a user to share his/her route with others by drawing on a digital map, naturally incorporating human knowledge into the trip planning process. The system gives driving instructions by overlaying navigational arrows onto live video and providing synthesized voice to reduce the driver's cognitive load, in addition to presenting landmark images for key maneuvers. We describe our observations which had motivated the development of the system, detailed architecture and user interfaces, and finally discuss our initial test findings in the real-road driving context.