The sintering of precious metal particles during the operation of automotive three-way catalysts is considered to reduce the catalytic activity, that is, degrade the catalyst. In this paper, we demonstrated that the Pt particles in Pt/ceria-based catalysts did not sinter at all during high-temperature ageing in an oxidizing atmosphere, in contrast with conventional Pt/Al₂O₃ catalysts. The sintering inhibition mechanism of Pt in Pt/ceria-based oxide catalyst has been studied using X-ray absorption spectroscopy. We found that the Pt-O-Ce bond, which is the Pt-oxide-support interaction, functioned as an anchor and inhibited the sintering of Pt particles on ceria-based oxide.

To realize optimal dynamic route guidance and arrival time prediction with the TOYOTA G-BOOK telematics service, we developed a new computational method that we call the "Three-range Composite Prediction Method." With this, we can predict travel times using traffic information provided by the VICS (Vehicle Information and Communication Systems). This method involves three prediction models and a process for combining them. The three models have been developed with the aim of both characterizing the dynamics of traffic flows and the regular patterns of traffic demand, which enable us to predict traffic conditions both in the immediate future and somewhat further in the future. The combining process calculates travel times by combining the outputs of the three models using weight coefficients that are optimized for every area, route, and time range. This combining process makes it possible to predict future travel times with higher accuracy over a longer time range.

We predicted the traffic situations for Expo 2005, held in Aichi, Japan, and evaluated the plan of measures, such as traffic restrictions, by using a traffic simulator NETSTREAM which we developed. This was done in response to a request from the Aichi Prefectual Police to evaluate their plans, given that we had had prior success with predicting traffic situations.

We predicted heavy traffic jams on the Chikaraishi-Nagoya Line which is a major road between Nagoya and the venues. In this paper, we describe our evaluation of possible traffic detour controls that could have been used to avoid this congestion. In addition, to maintain smooth-running transportation links for both buses and commuters, we also evaluated the use of exclusive bus lanes on the Nagoya-Seto Expressway which is the main expressway link from the Tomei Expressway.

Based on these predictions and evaluations, we confirmed that the traffic jam information, the exclusive bus lanes (used only on weekend mornings), the prohibition of private cars within 3 km of the Expo venues, and the use of Park & Ride schemes were indispensable for reducing traffic jams around the venues and on the main roads. During the Expo, thanks to the application of these measures, there were few traffic jams and all transportation links ran smoothly.