We present a novel traveler support system designed for use by intermodal travelers who often inevitably have to collate information related to their journeys from different information sources and integrate them to make their travel decisions. We first provide a brief overview of an intermodal passenger support system called "CyberGuide," then propose an intelligent and just-in-time information retrieval agent that takes into consideration passengers' temporal and spatial contexts, and present a new architecture for information integration in which diverse information related to their journeys is supplied to travelers in a proactive but nonintrusive manner.