In this paper, we describe two telematics applications that we developed based on TOPAZ platform. TOPAZ is a service-oriented open software infrastructure for telematics and U-city applications, currently under development by IBM Ubiquitous Computing Lab as a four year government project. We developed call taxi service and emergency rescue service for patient in u-health scenarios. Based on TOPAZ application services such as telemetry subscription service, spatio-temporal event detection service, content push service, etc and end-to-end application model, we could complete three different applications end-to-end within relatively short time period with minimal man power.