The rise of cell phones and connected vehicles has led to a vast pool of vehicle trip data—known as “telematics”—that is transforming transportation and air quality planning. ERG has developed industry-leading capacity for evaluating how this type of "big data" can be used to improve our understanding of vehicle emissions. Our innovative research in this domain can help improve air quality and greenhouse gas forecasts, allowing policymakers to make more informed decisions toward reducing emissions. In a study conducted for the Coordinating Research Council, ERG reviewed several sources of telematics data and conducted case studies to demonstrate how this emerging data source can be harnessed to better quantify transportation emissions. This project resulted in a study of telematics data in the peer-reviewed journal Transportation Research Record.